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Targeting Atherosclerotic Plaques with Stents made of Drug-eluting Biomaterials
Reporter: Daniel Menzin, BSc BioMedical Engineering, expected, May 2021, Research Assistant 4, Core Applications Developer and Acting CTO
Atherosclerosis is a chronic cardiovascular disease with a multitude of different implications. A coronary artery plaque may lead to congestive heart failure while an aortic plaque may cause angina. Both can quite possibly lead to a heart attack unless properly managed. One way to manage this condition is through the use of stents made of a mesh that is expanded following placement into the diseased vessel.
Unfortunately, stents are oftentimes initially effective but eventually restenosis occurs. Restenosis is a condition in which the affected vessel becomes blocked again. Cholesterol-rich blood vessel environments oftentimes lead to an irritation that results in white blood cells aggregating in the area and releasing proinflammatory chemokines and cytokines, which cause fibrosis. To make matters worse, the cholesterol plaques undergo compression against the vessel wall which causes vessel injury and further inflammation. This leads to thrombus formation and may potentiate neointimal hyperplasia, an abnormal proliferation and migration of smooth muscle cells in the tunica intima. Neointimal hyperplasia plays a major role in restenosis.
Recent research has found that interfacing drug eluting biomaterials with stents may help prevent restenosis. One study showed that rapamycin delivered with acid labile and ROS-sensitive forms of Beta-cyclodextrin produced promising results when treating atherosclerosis in rat models (Dou, et al). In this promising new paradigm of treatment, non-proinflammatory biomaterials are interfaced with stents. Once inflammation appears the biomaterial will begin to degrade, slowly releasing the drug which suppresses the underlying immune reaction and the resulting inflammation.
SOURCE
Dou Y;Chen Y;Zhang X;Xu X;Chen Y;Guo J;Zhang D;Wang R;Li X;Zhang J; “Non-Proinflammatory and Responsive Nanoplatforms for Targeted Treatment of Atherosclerosis.” Biomaterials, U.S. National Library of Medicine, 29 July 2017, pubmed.ncbi.nlm.nih.gov/28778000/.
Other related articles published in this Open Access Online Scientific Journal include:
Risks from Dual Antiplatelet Therapy (DAPT) may be reduced by Genotyping Guidance of Cardiac Patients
Reporter: Aviva Lev-Ari, PhD, RN
Genotyping Cardiac Patients May Reduce Risks From DAPT
-STEMI patient study reaches noninferiority mark for adverse cardiac events
by Vicki Brower,CME Writer, MedPage Today September 7, 2019
In the investigational arm, all 1,242 patients were tested for CYP2C19 loss-of-function alleles *2 or *3. Carriers received ticagrelor or prasugrel, while noncarriers received clopidogrel, considered to be less powerful.
No genetic testing was performed in the standard treatment arm (n=1,246), in which patients largely went on to receive ticagrelor or prasugrel. Nearly all patients in both cohorts received dual antiplatelet therapy (DAPT) with aspirin.
Following primary PCI, patients went on to the P2Y12 inhibitor for at least 12 months, with drug adherence similar between the genotype-guided (84.5%) and standard groups (82.0%).
For patients with CYP2C19 loss-of-function alleles in the genotype-guided arm, 38% received ticagrelor and 1% received prasugrel. The remaining 61% of patients — the noncarriers — received clopidogrel. In the control arm, 91% were treated with ticagrelor, 2% with prasugrel, and 7% with clopidogrel, according to local protocol.
Ten Berg said that prasugrel is not typically used in the Netherlands, where eight of the centers in the trial were located, but that this might change given that the drug lowered rates of ischemic events versus ticagrelor in the head-to-head ISAR REACT 5 trial, which was also presented at ESC.
Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco
Palmaz, Pinchuk, Schatz, Simpson and Yock are the 10th recipients of the Russ Prize for innovations leading to the widespread adoption of PCI at NAE Gala Ceremony, 2/20/2019, WashDC
Reporter: Aviva Lev-Ari, PhD, RN
National Academy of Engineering, Ohio University Award 2019 Russ Prize
Five interventional cardiologists awarded biennial $500,000 prize for innovations leading to the widespread adoption of PCI
January 3, 2019 — Ohio University and the National Academy of Engineering announced the 2019 Fritz J. and Dolores H. Russ Prize will be given to Julio Palmaz, Leonard Pinchuk, John Simpson, Richard Schatz and Paul Yock for innovations leading to the widespread adoption of percutaneous coronary intervention (PCI), also known as angioplasty with stent or coronary angioplasty. The $500,000 biennial prize, which recognizes a bioengineering achievement that significantly improves the human condition, cites PCI for “seminal contributions to coronary angioplasty, enabling minimally invasive treatment of advanced coronary artery disease.”
“The Russ Prize recipients personify engineering creations that advance health and healthcare every day,” said NAE President C. D. Mote, Jr. “The PCI makes a remarkable contribution to patient well-being, helping millions afflicted with advanced coronary artery disease and significant angina. “
Ohio University alumnus and esteemed engineer Fritz Russ, BSEE ’42, HON ‘75, and his wife, Dolores Russ, established the biennial prize in 1999 with a multimillion dollar gift to Ohio University. They modeled it after the Nobel Prize, with the goal of recognizing bioengineering achievements worldwide that are in widespread use.
“This innovation — truly, sets of innovations — enables the treatment of coronary artery disease without the complexities, cost and risk of open heart surgery. Most of us have a friend or relative who has benefited greatly from angioplasty treatment,” said Russ College Dean Dennis Irwin. “These contributions have truly improved the human condition. Rewarding such innovations was the Russes’ intent.”
Percutaneous coronary intervention, also referred to as percutaneous transluminal coronary angioplasty (PTCA), is a minimally invasive procedure that uses a catheter to place a small structure called a stent to open up blood vessels in the heart that have been narrowed by plaque buildup. PCI improves blood flow, thus decreasing heart-related chest pain, making patients feel better and increasing their ability to be active. Ten of millions of patients have benefited from PCI worldwide, and this procedure has replaced or significantly delayed the need for open heart coronary bypass surgery.
Julio C. Palmaz, inventor of the first U.S. Food and Drug Administration (FDA)-approved balloon-expandable vascular stent (1990), is Ashbel Smith Professor at the University of Texas Health Science Center in San Antonio and scientific adviser of Vactronix Scientific. The Palmaz stent is on display at the Smithsonian’s National Museum of American History in Washington, D.C. In 1994 he and Richard Schatz created a modified coronary stent — two Palmaz stents joined by a single connector — approved by the FDA as the first stent indicated for the treatment of failure of coronary balloon angioplasty. The Palmaz-Schatz stent became the gold standard for every subsequent stent submitted for FDA approval.
Leonard Pinchuk is an inventor and entrepreneur in biomedical engineering, with 128 U.S. patents and 90 publications. He has co-founded 10 companies where his major accomplishments include invention of the Nylon 12 angioplasty balloon, helical wire stent, modular stent-graft, a drug-eluting stent (Taxus), several biomaterials (Bionate and polystyrene-block-isobutylene-block-styrene [SIBS]), a novel glaucoma tube (InnFocus MicroShunt), and the next-generation intraocular lens. He is a Distinguished Research Professor of Biomedical Engineering at the University of Miami.
John Simpson has helped revolutionize the field of cardiology through innovations that fundamentally altered how physicians treat cardiovascular disease. In 1981 he created a new catheter system for coronary angioplasty with an independently steerable guidewire in the central lumen of the balloon catheter, patented as the over-the-wire balloon angioplasty catheter. He now focuses his efforts on the treatment of vascular disease through the development of new technologies combined with a new approach to optical imaging.
Richard Schatz is research director of cardiovascular interventions at the Scripps Heart, Lung and Vascular Center, and director of gene and stem cell therapy. He is a recognized international expert in interventional cardiology and has published and lectured extensively. His seminal work in coronary stents spurred a revolution in the treatment of coronary artery disease — over 2 million of them are placed annually worldwide, with an immeasurable impact on relieving mortality and morbidity, improving patients’ lives, and reducing healthcare costs.
Paul Yock is the Martha Meier Weiland Professor of Medicine and founding co-chair of Stanford’s Department of Bioengineering, with courtesy appointments in the Graduate School of Business and the Department of Mechanical Engineering. He is also founder and director of the Stanford Byers Center for Biodesign. He has authored over 300 peer-reviewed publications, chapters, and editorials and two textbooks, and holds over 50 U.S. patents. Yock is internationally known for his work in inventing, developing and testing new devices, including the Rapid Exchange stenting and balloon angioplasty system, which is now the primary system in use worldwide. He also invented the fundamental approach to intravascular ultrasound imaging and founded Cardiovascular Imaging Systems (CVIS), later acquired by Boston Scientific.
“Ohio University is honored to join the National Academy of Engineering in recognizing these accomplished individuals, who have contributed to a bioengineering advancement that has enabled better health for heart patients across the world,” said Ohio University President M. Duane Nellis. “Their multi-disciplinary collaboration that lead to the development of PCI, a technology that has revolutionized coronary health, truly embraces the vision that Fritz and Dolores Russ had when creating the Russ Prize.”
Palmaz, Pinchuk, Schatz, Simpson and Yock are the 10th recipients of the Russ Prize. They will receive the award at a National Academy of Engineering gala ceremony in Washington, D.C., on Feb. 20, 2019
BLOG | DAVE FORNELL, DAIC EDITOR | DECEMBER 11, 2018
A 40,000 Foot View of Trends in Cardiology
I was recently asked about my thoughts on the big picture, over arching trends effecting cardiology. Here is the outline I gave them.
Cardiology Cost Drivers
Reimbursements from Centers for Medicare and Medicaid Services (CMS) and insurance providers drive trends for the adoption of new technologies. However, new technologies that can show empirical evidence for being able to improve outcomes at lower costs are being moved up for better payments. CMS and other insurers are also using a carrot and stick approach with increased use of CMS bundled payments. These give a flat fee for diagnosing and treating a heart attack or heart failure, rather than hospitals being paid for all the tests and procedures they did. This approach makes the hospitals want to find new ways to be more cost effective to increase their bottom lines to capture more of the bundled payment as revenue.
Heart failure makes up about a third or more of the costs to Medicare. This has caused CMS to look closely at what is driving costs, and really high readmission rates are mainly to blame. There are penalties or no reimbursements for patients who come back for repeat treatments because they were not managed properly the first time. New technologies to address heart failure and other chronic diseases are of major interest to DAIC readers. Many of these include information technology (IT) solutions, rather than treatment device technologies.
Other conditions like atrial fibrillation (AF) also drive up costs, so vendors are attempting to find better ways to diagnose and treat this condition. Current treatments are only effective in the first attempt in about 60 percent of patients.
Consolidation of Hospitals and Outside Physicians
This is a continuing trend where single hospitals or smaller hospital systems are being bought up by bigger fish to create economy of scale with larger healthcare systems. These often cover specific geographic areas and often cast a wide net to include some luminary hospitals, smaller community hospitals, immediate care centers and minute clinics inside drug partner pharmacies. Duplicate staff and services are sometimes eliminated after mergers and consolidation. Outside physicians, including cardiologists and radiologists, are also being brought into the fold as employees of the health systems, rather than the old model as outside contractors who have access to the hospital’s amenities.
Any techniques and technologies that can improve outcomes, cut costs, reduce hospital length of stay or prevent readmissions can capture hospital and cardiologist attention in today’s healthcare environment. There has been a massive movement over the past two decades away from traditional open heart or vascular surgical procedures to catheter-based interventional procedures. This includes improvements in the durability and complexity of percutaneous coronary intervention (PCI), reopening chronic total occlusions (CTOs), endovascular aortic repair (EVAR), expanded interest in treating peripheral artery disease (PAD), and structural heart cases that used to be the realm of the cardiac surgeon.
There is a major revolution and rapid uptake in transcatheter valve technologies to replace open heart surgery. Structural heart procedures to repair or replace failing heart valves have had positive clinical trial after positive trial over the last several years. Several key cardiac surgeons in the field say catheter based interventions will likely be the way of the future and surgical case volumes will see stead declines over the next decade.
The Role of Information Technology and AI in Cardiology
IT solutions are now increasingly being leveraged in more sophisticated ways since most hospitals have converted to integrated electronic medical records (EMRs) over the past decade. These allow all patient and departmental data to be accessible in one location. Analytics software is now being used to mine this data to identify workflow inefficiencies and areas to cut costs or improve charge capture. Clinical decision support (CDS) software to help hospitals and doctors better meet guideline-based care in all specialties is being introduced to help clinicians make better care decisions. This includes choosing appropriate tests and procedures in an effort to reduce costs or avoid tests that will not be reimbursed.
Artificial intelligence (AI) will be taking over many of the manual tasks for monitoring data and to answer questions more quickly. AI will also be used to alert administrators or doctors when it autonomously identifies a problem. Applications to watch also include AI to monitor population health in the background. This can identify patients at risk for various cardiovascular diseases before they present with any symptoms. The software also can identify patients who need extra care and counseling because of the high likelihood they will not be compliant with discharge orders and be readmitted. AI also will offer a second set of eyes on cardiac imaging to help identify anomalies or greatly reduce time by performing all the measurements automatically without human intervention.
This use of IT also includes patient portals to engage with patients and allow better access to their records and care. This is already starting to filter down to apps on smart phones to improve care, compliance with doctor’s orders and to aid diagnosis of conditions before they become problematic, such as heart failure and AF.
Cardiac Imaging Trends
Cardiac ultrasound (echo) remains the No.1 imaging modality in cardiology because of its broad availability, low cost and no radiation. However, computed tomography (CT) is poised to become the front-line imaging test for acute chest pain patients in the emergency department. It is also the gold standard for structural heart procedure planning, and the number of these cases is rapidly rising. CT fractional flow reserve (CT-FFR) technology is widely expected to become the main test for chest pain in the next decade, since it has the potential to save both time and money. CT-FFR also will become the primary gate-keeper to the cath lab to significantly lower, or possibly eliminate, the need for diagnostic catheter angiograms.
Cardiac MRI has seen numerous advances in recent years that cut imaging times by 50 percent and automate quantification, cutting the time to read and process these exams. MRI is expected to see and increase for cardiac exams in the coming years. MRI and CT-FFR may greatly reduce the number of nuclear exams, which are currently the gold standard for cardiac perfusion imaging.
The FDA approved the first ultrathin strut drug-eluting stent, Orsiro, as well as a shelf-stable, premixed vancomycin injection for infective endocarditis and other indications.
Dual antiplatelet therapy with ticagrelor (Brilinta) reduced major adverse cardiovascular events in type 2 diabetes patients with coronary artery disease but no prior heart attack or stroke, Astra Zeneca announced in topline results from the THEMIS trial. However, no numerical data were released.
Coronary Artery Interventions: Balloon, Stent, Drug-eluting Stent and Antiplatelet Demand
Curator: Justin D. Pearlman, MD, PhD, FACC
Italicized text represents the voice of Dr. Pearlman
Coronary Artery Disease (CAD), causing impeded blood supply to the heart, constitutes a major cause of disability and death, amounting to triple all forms of cancer combined. The warning symptoms may include a decline in exertion tolerance, usually accompanied by additional symptoms known as “chest pain.” However, “chest pain” is an inaccurate term because it may not be in the chest and it may not include pain (commonly, “chest pain” may occur in the neck, jaw, anterior chest and/or left arm, and may just felt as a light pressure, squeezing, ache, or sense of doom, sometimes with sweating, nausea and/or palpitations, the sensation of abnormal heart beats).
Dr. Heberden is credited with establishing the diagnostic malady called “angina pectoris.” Angina Pectoris corresponds to obstruction in a coronary artery resulting in exertion-limiting symptoms related to effort (cardiac demand), typically in the chest, neck, jaw and/or arm. The term “angina pectoris” literally means sore throat in the chest. Classic angina is a pressure in the chest that moves to the left arm, reproducible at a particular degree of exertion, such as climbing 1 flight of stairs, that is relieved withing 5 minutes of rest or sublingual nitroglycerin. Other patterns of pain are called “atypical” either because they represent a different expression of the same disease, or because they are not cardiac in etiology. Many studies report that women with CAD are more often “atypical,” which can lead to missed diagnosis.
The first right heart catheterization in a human was performed by Werner Forssmann on himself in 1929. Diagnostic cardiac catheterization was introduced by André Cournand and Dickinson Richards in the early 1940s. Dr. Palin and others identified focal partial blockages in patients with angina by injecting the aorta with iodinated contrast agents followed by x-ray imaging. Selective coronary angiography was described by Mason Sones in the early 1960s, based on an accidental engagement of a catheter into a coronary origin during aortography.
The facts that coronary angiography generally leads to intervention, and has some risk of damaging an artery and possibly triggering a heart attack, has promoted widespread use of “stress tests” to screen for risk level prior to consummating a decision to perform angiography for elevated coronary risk findings. Coronary revascularization has proven beneficial for classic “ST elevation” heart attacks or the equivalent presenting as a new left bundle block, within the first 6-12 hours of onset, preferably within 1 hour, and also for blockages with poor “flow reserve” involving all tree coronary territories or the left main coronary artery. Also, revascularization provides a means to relieve angina as an alternative to medications for patients with lesser disease, even though that has not been shown to be reliable in prevention of future heart attacks. Some patients, particularly those with diffuse coronary disease not suitable for stents or bypass, undergo a repeated challenge of compression to the legs and buttocks called “EECP” (enhanced external couterpulsation) to stimulate natural remodeling of the blood supply to the heart, some, after severe damage substantially weakens the heart, take on the cancer and infection risks of a immunosuppression heart transplant, and some receive a mechanical heart or a left ventricular assist pump.
Whereas some “stress tests” check for “rush hour traffic jams” by checking status at baseline and then when speeding up the heart with an exercise challenge, other forms of “stress testing” use chemicals either to speed up the heart rate, to stimulate higher workload conditions, or just to increase blood flow in the coronary arteries (increase traffic by arterial dilation without stress). Thus, just as “chest pain” does not have to include chest or pain, stress tests do not have to include stress.
Keywords: In-stent restenosis (ISR), stent thrombosis (ST), bare metal stents (BMS), drug-eluting stent (DES), drug-coated balloon (DCB), paclitaxel-eluting balloon (PEB)
The evolution of cardiac catheterization has occurred over at least four centuries. One of the first major steps was the description of the circulation of the blood by William Harvey in 1628. The next milestone was the measurement of arterial pressure by Stephen Hales, one century later. The 19th century represented the golden age of cardiovascular physiology, highlighted by the achievements of Carl Ludwig (physiology of blood pressure), Etienne-Jules Marey (pulse and blood pressure measurement) and Claude Bernard (vasomotor control of blood supply), among others. Human cardiac catheterization developed during the 20th century. The first right heart catheterization in a human was performed by Werner Forssmann on himself in 1929. Diagnostic cardiac catheterization was introduced by André Cournand and Dickinson Richards in the early 1940s, and selective coronary angiography was described by Mason Sones in the early 1960s. More recently, with the advent of catheter-based interventions, pioneered by Andreas Gruentzig in the late 1970s, there has been considerable progress in the refinement and expansion of these techniques. Currently, the Sones technique (direct cannulation of a coronary artery) substantially replaced the previously indirect aortography coronary angiography. Both selective coronary angiography and percutaneous coronary intervention rely mainly on percutaneous femoral and percutaneous radial artery entry routs.
On the occasion of the 50th anniversary of the Montreal Heart Institute, we will highlight the contributions of that institution on selective coronary angiography and percutaneous coronary interventions.
Restenosis is a progressive phenomenon that begins in the early hours after the barotrauma from PCI (Table 1).
Table 1
Time-related assessment of in-stent restenosis (ISR)
Early (within days)
Elastic return (recoil) (ER)
Relocation of axially transmitted plaque
Late (weeks to months)
Reorganization of thrombus
Neointima formation
Cell proliferation
Cell migration
Cell matrix synthesis
Remodelling
Resolution of inflammation
ISR, in-stent restenosis; ER, elastic recoil.
The three major pathogenic mechanisms that underlie restenosis are:
Early elastic return (recoil) (ER);
Vascular remodeling;
Neointimal hyperplasia.
The first and the second mechanisms are typical of “old-style” or “plain old balloon” angioplasty (POBA) before the stent era. The presence of metallic struts from stents promotes a new mechanism called neointimal hyperplasia.
Myointimal trauma induced by PCI affects the atherosclerotic process and changes its course from the natural evolution of atherosclerotic plaque to a more aggressive local response to the treatment. Atherosclerosis is characterized by a sequence of processes which induce vasoconstriction and the initial endothelial dysfunction resulting in the mechanism of endoplasmic reticulum (ER and vascular remodelling, enhanced by an inflammatory process triggered by vessel injury, as evidenced by the increase in C-reactive protein or MCP-1 in patients at increased risk of restenosis (20).
SOURCES
The following articles review the benefits of stents to keep coronary arteries propped open after balloon expansion of a focal area of blockage. These articles establish the motivation for drug-eluting stents to address the problem that stents introduced of stimulating a tissue reaction which causes early in-stent re-stenosis (tissue in-growth obstructing the desired blood channel).
Research findings which support the widespread use of drug-eluting stents and uninterrupted use of strong antiplatelet agents
TI In-stent restenosis in the drug-eluting stent era.
AU Dangas GD, Claessen BE, Caixeta A, Sanidas EA, Mintz GS, Mehran R
SO J Am Coll Cardiol. 2010;56(23):1897.
The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing rates of restenosis and target lesion revascularization after percutaneous coronary intervention. However, the rapid implementation of DES in standard practice and expansion of the indications for percutaneous coronary intervention to high-risk patients and complex lesions also introduced a new problem: DES in-stent restenosis (ISR), which occurs in 3% to 20% of patients, depending on patient and lesion characteristics and DES type. The clinical presentation of DES ISR is usually recurrent angina, but some patients present with acute coronary syndrome. Mechanisms of DES ISR can be biological, mechanical, and technical, and its pattern is predominantly focal. Intravascular imaging can assist in defining the mechanism and selecting treatment modalities. Based upon the current available evidence, an algorithm for the treatment approaches to DES restenosis is proposed.AD
Cardiovascular Institute, Mount Sinai Medical Center, New York, New York 10029, USA. george.dangas@mssm.eduPMID
This is an early report on advantages of stent placement over the prior “plain old balloon angioplasty” (POBA).
AU Fischman DL, Leon MB, Baim DS, Schatz RA, Savage MP, Penn I, Detre K, Veltri L, Ricci D, Nobuyoshi M
SO N Engl J Med. 1994;331(8):496.
BACKGROUND: Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes.
METHODS: We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later.
RESULTS: The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P<0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, Por = 50 percent) of 22 and 32 percent, respectively (P = 0.02). Peripheral vascular complications necessitating surgery, blood transfusion, or both were more frequent after stenting than after balloon angioplasty (13.5 vs. 3.1 percent, P<0.001). The mean hospital stay was significantly longer in the stent group than in the angioplasty group (8.5 vs. 3.1 days, Por =50% follow-up diameter stenosis [DS]) in 419 of 1,437 (29%) patients undergoing routine angiographic follow-up correlated directly with the likelihood of TLR (73% vs. 26% for>70% DS compared with<60% DS). Smaller pretreatment minimum lumen diameter (MLD), smaller final MLD, longer stent length, diabetes mellitus, unstable angina, and hypertension were independent predictors of TLR. Prior MI and current smoking were negative predictors.
CONCLUSIONS: At one year after stenting, most clinical restenosis reflected TLR, which was predicted by the same variables previously associated with an increased risk of angiographic restenosis. The lower absolute rate of clinical restenosis relative to angiographic restenosis was due to infrequent TLR in lesions with less severe (28 mm for very late ST. Independent risk factors of late target lesion revascularization beyond 1 year were generally similar to those risk factors identified for early target lesion revascularization.
CONCLUSION: Late adverse events such as very late ST and late target lesion revascularization are continuous hazards, lasting at least up to 5 years after implantation of the first-generation drug-eluting stents (sirolimus-eluting stents), which should be the targets for developing improved coronary stents.
The following reports clarified the basis for early stent re-stenosis, first by intravascular miniaturized ultrasound imaging of the problem, then by animal models.
AD Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, Japan. taketaka@kuhp.kyoto-ua.ac.jp
AU Hoffmann R, Mintz GS, Dussaillant GR, Popma JJ, Pichard AD, Satler LF, Kent KM, Griffin J, Leon MB
SO Circulation. 1996;94(6):1247.
BACKGROUND: Studies have suggested that restenosis within Palmaz-Schatz stents results from neointimal hyperplasia or chronic stent recoil and occurs more frequently at the articulation.
METHODS AND RESULTS: Serial intravascular ultrasound (IVUS) was performed after intervention and at follow-up in 142 stents in 115 lesions. IVUS measurements (external elastic membrane [EEM], stent, and lumen cross-sectional areas [CSAs]and diameters) were performed, and plaque CSA (EEM lumen in reference segments and stent lumen in stented segments), late lumen loss (delta lumen), remodeling (delta EEM in reference segments and delta stent in stented segments), and tissue growth (delta plaque) were calculated. After intervention, the lumen tended to be smallest at the articulation because of tissue prolapse. At follow-up, tissue growth was uniformly distributed throughout the stent; the tendency for greater neointimal tissue accumulation at the central articulation reached statistical significance only when normalized for the smaller postintervention lumen CSA. In stented segments, late lumen area loss correlated strongly with tissue growth but only weakly with remodeling. Stents affected adjacent vessel segments; remodelingprogressively increased and tissue growth progressively decreased at distances from the edge of the stent. These findings were similar in native arteries and saphenous vein grafts and in lesions treated with one or two stents. There was no difference in the postintervention or follow-up lumen (at the junction of the two stents) when overlapped were compared with nonoverlapped stents.
CONCLUSIONS: Late lumen loss and in-stent restenosis were the result of neointimal tissue proliferation, which tended to be uniformly distributed over the length of the stent.
Animal modeling as well as human sample histology showed biochemical basis for stent tissue in-growth which lead to effective choices for drug-eluting stents to release chemicals slowly over a long time to counteract that issue. However, the treatment may be too effective, as it also blocks protective endothelial lining of the stents, so blood products in circulation passing through a stent remain exposed to trauma that can promote thrombosis.
AD Intravascular Ultrasound Imaging and Cardiac Catheterization Laboratories, Washington Hospital Center, Washington, DC, USA
AU Kornowski R, Hong MK, Tio FO, Bramwell O, Wu H, Leon MB
SO J Am Coll Cardiol. 1998;31(1):224.
OBJECTIVES: We examined the relative contributions of inflammation and arterial injury to neointimal formation in a porcine coronary overstretch restenosis model.
BACKGROUND: Previous studies established that stents cause neointimal proliferation proportional to injury. Although inflammation has been postulated to be a major contributor to restenosis after angioplasty, there is a paucity of data on the relation between inflammation and subsequent neointimal formation.
METHODS: Twenty-one pigs underwent balloon injury followed by implantation of oversized, tubular, slotted stents (stent/artery ratio 1.2:1) in the left anterior descending coronary artery. Morphometric analysis of the extent of injury (graded as injury score 0 to 3) and inflammation (graded as inflammation score 0 to 3) 1 month later was assessed and correlated with neointimal formation.
RESULTS: An inflammatory reaction was observed in 20 of 21 pigs, and significant positive correlations were found between the degree of arterial injury and the extent of the inflammatory reaction (r = 0.80, p<0.01) and between the extent of inflammatory reaction and the neointimal thickness (r = 0.75, p<0.01), neointimal area (r = 0.53, p = 0.01) and percent area stenosis (r = 0.66, p<0.01) within the stents. Importantly, there were areas with inflammation only in the absence of injury, and vice versa, that were also associated with neointimal hyperplasia.
CONCLUSIONS: These data suggest that the inflammatory reaction plays an equally important role as arterial injury in neointimal formation after coronary stenting, and that anti-inflammatory approaches may be of value to reduce in-stent restenosis.
AD Department of Internal Medicine (Cardiology Division) and Medlantic Research Institute of the Washington Hospital Center, DC, USA.
AU Komatsu R, Ueda M, Naruko T, Kojima A, Becker AE
SO Circulation. 1998;98(3):224.
BACKGROUND: Experimental animal studies have shown that coronary stenting induces neointimal proliferation. However, the histopathological events after coronary stenting in humans have not been studied systematically.
METHODS AND RESULTS: We investigated 11 stented coronary arteries (9 Palmaz-Schatz stents, 1 Wiktor stent, and 1 ACS Multi-Link stent) obtained from 11 patients who had died 2 days to 21 months after stenting. We focused on gross, histological, and immunohistochemical aspects of the repair processes. Two patients developed symptoms of restenosis. Serial sections were stained with antibodies against smooth muscle cells (SMCs), macrophages, and endothelial cells. At 9 and 12 days after stenting, the stent sites showed thrombus formation with early formation of neointima composed of abundant macrophages and alpha-actin-negative spindle cells. From 64 days on, all sites with stenting showed a distinct layer of neointima, albeit to varying degrees. In nonrestenotic lesions, neointimal thickening was markedly less than in restenotic lesions but without qualitative differences; the neointima contained macrophages but was composed predominantly of alpha-actin-positive SMCs.
CONCLUSIONS: These observations strongly support the concept that neointimal proliferation in humans is a process of staged redifferentiation of SMCs, which may cause in-stent stenosis. Moreover, the exuberant neointimal proliferation with accumulation of macrophages and extensive neovascularization at sites of stent restenosis suggests a role for organization of mural thrombus.
AD Department of Pathology, Osaka City University Medical School, Osaka, Japan.
AU Farb A, Sangiorgi G, Carter AJ, Walley VM, Edwards WD, Schwartz RS, Virmani R
SO Circulation. 1999;99(1):44.
BACKGROUND: Despite the increasing use of stents, few reports have described human coronary artery morphology early and late after stenting.
METHODS AND RESULTS: Histology was performed on 55 stents in 35 coronary vessels (32 native arteries and 3 vein grafts) from 32 patients. The mean duration of stent placement was 39+/-82 days. Fibrin, platelets, and neutrophils were associated with stent struts</=11 days after deployment. In stents implanted for20 associated inflammatory cells compared with 44% of struts embedded in a lipid core and 36% of struts in contact with damaged media (P<0.001). Neointimal growth determined late histological success, and increased neointimal growth correlated with increased stent size relative to the proximal reference lumen area. Neointimal thickness was greater for struts associated with medial damage than struts in contact with plaque (P<0.0001) or intact media (P<0.0001). When matched for time since treatment, neointimal cell density in stented arteries was similar to that in unstented arteries that had undergone balloon angioplasty and showed similar proteoglycan deposition.
CONCLUSIONS: Morphology after coronary stenting demonstrates early thrombus formation and acute inflammation followed by neointimal growth. Medial injury and lipid core penetration by struts result in increased inflammation. Neointima increases as the ratio of stent area to reference lumen area increases. Deployment strategies that reduce medial damage and avoid stent oversizing may lower the frequency of in-stent restenosis.
AD Department of Cardiovascular Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
AU Chung IM, Gold HK, Schwartz SM, Ikari Y, Reidy MA, Wight TN
SO J Am Coll Cardiol. 2002;40(12):2072.
OBJECTIVES: The goal of this study was to evaluate the cellular and extracellular composition of human coronary arterial in-stent restenosis after various periods of time following stent deployment.
BACKGROUND: Neointimal in-growth rather than stent recoil is thought to be important for coronary arterial in-stent restenosis. There is only limited data on the cellular and extracellular composition changes with time after stent deployment.
METHODS: We analyzed 29 coronary arterial in-stent restenotic tissue samples (14 left anterior descending coronary artery, 10 right coronary artery, and 5 left circumflex artery) retrieved by using directional coronary atherectomy from 25 patients at 0.5 to 23 (mean, 5.7) months after deployment of Palmaz-Schatz stents employing histochemical and immunocytochemical techniques.
RESULTS: Cell proliferation was low (0% to 4%). Myxoid tissue containing extracellular matrix (ECM) enriched with proteoglycans was found in 69% of cases and decreased over time after stenting. Cell-depleted areas were found in 57% of cases and increased with time after stenting. Versican, biglycan, perlecan, and hyaluronan were present with varying individual distributions in all samples. Positive transforming growth factor-beta1 staining was found in 80% of cases. Immunostaining with alpha-smooth muscle actin identified the majority of cells as smooth muscle cells with occasional macrophages present (<or =12 cells per section).
CONCLUSIONS: These data suggest that enhanced ECM accumulation rather than cell proliferation contribute to later stages of in-stent restenosis. Balloon angioplasty of in-stent restenosis may, therefore, fail due to ECM changes during: 1) additional stent expansion, 2) tissue extrusion out of the stent, or 3) tissue compression.
AD Department of Pathology, University of Washington, Seattle, USA.
AU Kimura T, Yokoi H, Nakagawa Y, Tamura T, Kaburagi S, Sawada Y, Sato Y, Yokoi H, Hamasaki N, Nosaka H
SO N Engl J Med. 1996;334(9):561.
BACKGROUND: Coronary-artery stents are known to reduce rates of restenosis after coronary angioplasty, but it is uncertain how long this benefit is maintained.
METHODS: We evaluated clinical and angiographic follow-up information for up to three years after the implantation of Palmaz-Schatz metallic coronary-artery stents in 143 patients with 147 lesions of native coronary arteries.
RESULTS: The rate of survival free of myocardial infarction, bypass surgery, and repeated coronary angioplasty for stented lesions was 74.6 percent at three years. After 14 months, revascularization of the stented lesion was necessary in only three patients (2.1 percent). In contrast, coronary angioplasty for a new lesion was required in 11 patients (7.7 percent). Follow-up coronary angiography of 137 lesions at six months, 114 lesions at one year, and 72 lesions at three years revealed a decrease in minimal luminal diameter from 2.54 +/- 0.44 mm immediately after stent implantation to 1.87 +/- 0.56 mm at six months, but no further decrease in diameter at one year (in patients with paired angiograms, 1.95 +/- 0.49 mm at both six months and one year). Significant late improvement in luminal diameter was observed at three years (in patients with paired angiograms, 1.94 +/- 0.48 mm at six months and 2.09 +/- 0.48 mm at three years; P<0.001).
CONCLUSIONS: Clinical and angiographic outcomes up to three years after coronary-artery stenting were favorable, with a low rate of revascularization of the stented lesions. Late improvement in luminal diameter appears to occur between six months and three years.
AD Department of Cardiology, Kokura Memorial Hospital, Kitakyushu, Japan.
AU Asakura M, Ueda Y, Nanto S, Hirayama A, Adachi T, Kitakaze M, Hori M, Kodama K
SO Circulation. 1998;97(20):2003.
BACKGROUND: Recently, it has been reported that the luminal diameter shows phasic changes after stenting: the progression of luminal narrowing followed by its regression. To elucidate the mechanisms involved in the phasic changes in luminal diameter after stenting, we examined the changes in neointimal thickness and the appearance of neointima by a series of angiographic and angioscopic observations for 3 years after stent implantation.
METHODS AND RESULTS: In 12 patients who received a Wiktor coronary stent, serial angiographic and angioscopic examinations were performed immediately, 2 to 4 weeks, 3 months, 6 months, and 3 years after the stenting without repetition of angioplasty. Neointimal thickness was determined by angiography as the difference between stent and luminal diameters. The angioscopic appearance of neointima over the stent was classified as transparent or nontransparent according to the visibility of the majority of the stent. Neointimal thickness increased significantly at 3 months (0.75+/-0.32 mm) without further changes at 6 months (0.74+/-0.32 mm). Thereafter, however, it decreased significantly over 3 years (0.51+/-0.26 mm). The angioscopic appearance was classified as transparent in 8 patients (100) immediately after stenting, 6 patients (100%) at 2 to 4 weeks, 2 patients (17%) at 3 months, 2 patients (20%) at 6 months, and 7 patients (58%) at 3 years.
CONCLUSIONS: The neointima became thick and nontransparent until 6 months and then became thin and transparent by 3 years. We conclude that neointimal remodeling exists after stenting and plays a major role in the alteration of coronary luminal diameter after stenting.
AD Cardiovascular Division, Osaka Police Hospital, Japan.
AU Kuroda N, Kobayashi Y, Nameki M, Kuriyama N, Kinoshita T, Okuno T, Yamamoto Y, Komiyama N, Masuda Y
SO Am J Cardiol. 2002;89(7):869.
Although previous randomized trials 1-2 have demonstrated lower restenosis rates in selected lesions with coronary stents than with conventional balloon angioplasty. in-stent restenosis remains an important clinical problem.(3,4) Previous serial angiographic studies(5,6) showed that lumen loss after stenting occurred within 6 months. On the other hand, improvements in lumen dimensions between 6 months and 2 to 3 years have been demonstrated by angiography.(6-9) Serial (postintervention and at 6-month follow-up) intravascular ultrasound (IVUS) studies(10,11) have demonstrated that coronary stenting eliminates negative arterial remodeling, and thus intimal hyperplasia is solely responsible for in-stent restenosis. However, little has been reported about changes in intimal hyperplasia that occur beyond this 6-month period. This serial IVUS study evaluated the changes in intimal hyperplasia between 6 and 12 months after stent placement.
AD The Third Department of Internal Medicine, Chiba University, Chiba, Japan.
AU Mehran R, Dangas G, Abizaid AS, Mintz GS, Lansky AJ, Satler LF, Pichard AD, Kent KM, Stone GW, Leon MB
SO Circulation. 1999;100(18):1872.
BACKGROUND: The angiographic presentation of in-stent restenosis (ISR) may convey prognostic information on subsequent target vessel revascularizations (TLR).
METHODS AND RESULTS: We developed an angiographic classification of ISR according to the geographic distribution of intimal hyperplasia in reference to the implanted stent. Pattern I includes focal (10 mm within the stent, pattern III includes ISR>10 mm extending outside the stent, and pattern IV is totally occluded ISR. We classified a total of 288 ISR lesions in 245 patients and verified the angiographic accuracy of the classification by intravascular ultrasound. Pattern I was found in 42% of patients, pattern II in 21%, pattern III in 30%, and pattern IV in 7%. Previously recurrent ISR was more frequent with increasing grades of classification (9%, 20%, 34%, and 50% for classes I to IV, respectively; P=0.0001), as was diabetes (28%, 32%, 39%, and 48% in classes I to IV, respectively; P<0.01). Angioplasty and stenting were used predominantly in classes I and II, whereas classes III and IV were treated with atheroablation. Final diameter stenosis ranged between 21% and 28% (P=NS among ISR patterns). TLR increased with increasing ISR class; it was 19%, 35%, 50%, and 83% in classes I to IV, respectively (Por =50%, late lumen loss as lumen diameter reduction and target lesion revascularization (TLR) as any repeat PTCA or coronary artery bypass surgery involving the stented lesion.
RESULTS: Multivariate analysis demonstrated that diabetes mellitus, placement of multiple stents and minimal lumen diameter (MLD) immediately after stenting were the strongest predictors of restenosis. Diabetes increased the risk of binary restenosis with an odds ratio (OR) [95% confidence interval]of 1.86 [1.56 to 2.16]and the risk of TLR with an OR of 1.45 [1.11 to 1.80]. Multiple stents increased the risk of binary restenosis with an OR of 1.81 [1.55 to 2.06]and that of TLR with an OR of 1.94 [1.66 to 2.22]. An MLDor = 50% diameter stenosis at follow-up angiography, diffuse restenosis as a follow-up lesion length>or = 10 mm and aggressive restenosis as either an increase in lesion length from the original lesion or a restenotic narrowing tighter than the original. Clinical, anatomic and procedural characteristics were evaluated for lesions associated with these types of restenosis.
RESULTS: Diffuse restenosis was associated with a smaller reference artery diameter, longer lesionlength, female gender, longer stent length and the use of coil stents. Aggressive restenosis was more common in women, with the use of Wallstents and with long stent to lesion length ratios. Aggressive restenosis occurred earlier and was more closely associated with symptoms and myocardial infarctions than nonaggressive restenotic lesions.
CONCLUSIONS: Markers for diffuse restenosis were also important markers for the presence of any restenosis. A long stent to lesion length ratio is an important marker for aggressive restenosis. When severe forms of in-stent restenosis occur, they tend to present earlier and with more symptoms, including myocardial infarction. More careful consideration of the type of in-stent restenosis may aid in identifying when alternative strategies may be useful.
AD Harbor-UCLA Medical Center, Torrance, California, USA. stevgold@u.washington.edu
AU Mercado N, Boersma E, Wijns W, Gersh BJ, Morillo CA, de Valk V, van Es GA, Grobbee DE, Serruys PW
SO J Am Coll Cardiol. 2001;38(3):645.
OBJECTIVES: We sought to assess whether coronary stents have modified the predictive value of demographic, clinical and quantitative coronary angiographic (QCA) predictors of coronary restenosis.
BACKGROUND: A systematic analysis in a large cohort of registries and randomized trials of the percutaneous transluminal coronary angioplasty (PTCA) and stent era has never been performed.
METHODS: A total of 9,120 treated lesions in 8,156 patients included in nine randomized trials and 10 registries, with baseline, post-procedural and six-month follow-up QCA analyses, were included in this study. Predictors of restenosis were identified with univariate and multivariate logistic regression analyses. Interaction terms were introduced in the regression equation to evaluate whether the predictors of restenosis were common to both eras or specific for either one of the revascularization techniques.
RESULTS: The restenosis rate was 35% after PTCA and 19% after angioplasty with additional stenting. In the univariate analysis, favorable predictors were previous coronary artery bypass graft surgery (CABG), stent use, stent length and a large pre-procedural minimal lumen diameter (pre-MLD); unfavorable predictors were weight, body mass index, diabetes mellitus, multi-vessel disease, lesion length and a high residual post-procedural diameter stenosis (post-DS). Predictors specific for the PTCA population were a large post-procedural MLD (post-MLD) as favorable and a severe pre-procedural DS (pre-DS) as unfavorable. Favorable predictors specific for the stent population were a large post-MLD and a large pre-procedural reference diameter (pre-RD). In the multivariate analysis, the best model included the following favorable predictors: stent use, a large post-MLD, previous CABG and the interaction term between stent use and a large post-MLD; unfavorable predictors were lesion length and diabetes mellitus.
CONCLUSIONS: There are no major differences in demographic and clinical predictors of coronary restenosis between PTCA and stent populations. In the modern (stent) era, a severe pre-DS is no longer an unfavorable predictor of restenosis. Still important, but more so in the stent population, is a large post-MLD (optimal result). Finally, a larger pre-RD became a favorable predictor with the advent of stenting.
AD Thoraxcenter, University Hospital Dijkzigt, Rotterdam, The Netherlands.
AU Kobayashi Y, De Gregorio J, Kobayashi N, Akiyama T, Reimers B, Finci L, Di Mario C, Colombo A
SO J Am Coll Cardiol. 1999;34(3):651.
OBJECTIVES: We sought to evaluate the relation between stented segment length and restenosis.
BACKGROUND: Multiple or long coronary stents are now being implanted in long lesions or in tandem lesions. A longer stented segment might result in a higher probability of restenosis. However, there is little information available on the relation between stented segment length and restenosis.
METHODS: Between April 1995 and December 1996, 725 patients with 1,090 lesions underwent stenting. Lesions were divided into three groups according to the length of the stented segment: 1) group I (n = 565): stented segment length20 but35 mm.
RESULTS: There was no significant difference in the incidence of subacute stent thrombosis among the three groups (0.4% in group I, 0.4% in group II, 1.2% in group III; p = NS). The minimal lumen diameter (MLD) after stenting was greater in group I than in group III (3.04 +/- 0.60 mm in group I, 3.01 +/- 0.54 mm in group II, 2.91 +/- 0.58 mm in group III; p<0.05). At follow up, a smaller MLD was observed in group III as compared with group I and group II (2.04 +/- 0.93 mm in group I, 1.92 +/- 1.00 mm in group II, 1.47 +/- 0.97 mm in group III; p<0.01). The restenosis rates were 23.9% in group I, 34.6% in group II and 47.2% in group III (p36 mm, and (7) bifurcation stenting. The present study population was composed of 238 patients (441 lesions) for whom 6-month angiographic follow-up data were obtained (70% of eligible patients). Significant clinical, angiographic, and procedural predictors of post-SES restenosis were evaluated. Binary in-segment restenosis was diagnosed in 7.9% of lesions (6.3% in-stent, 0.9% at the proximal edge, 0.7% at the distal edge). The following characteristics were identified as independent multivariate predictors: treatment of in-stent restenosis (OR 4.16, 95% CI 1.63 to11.01; P<0.01), ostial location (OR 4.84, 95% CI 1.81 to 12.07; P<0.01), diabetes (OR 2.63, 95% CI 1.14 to 6.31; P=0.02), total stented length (per 10-mm increase; OR 1.42, 95% CI 1.21 to 1.68; P<0.01), reference diameter (per 1.0-mm increase; OR 0.46, 95% CI 0.24 to 0.87; P=0.03), and left anterior descending artery (OR 0.30, 95% CI 0.10 to 0.69; P<0.01).
CONCLUSIONS: Angiographic restenosis after SES implantation in complex patients is an infrequent event, occurring mainly in association with lesion-based characteristics and diabetes mellitus.
AD Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands.
AU Prati F, Di Mario C, Moussa I, Reimers B, Mallus MT, Parma A, Lioy E, Colombo A
SO Circulation. 1999;99(8):1011.
BACKGROUND: The aim of this study was to evaluate the relationship between residual plaque burden after coronary stent implantation and the development of late in-stent neointimal proliferation.
METHODS AND RESULTS: Between January 1996 and May 1997, 50 patients underwent intravascular ultrasound (IVUS) interrogation at 6+/-1.2 months after coronary stent implantation in native coronary arteries. IVUS images were acquired with a motorized pullback, and cross-sectional measurements were performed within the stents at 1-mm intervals. The following measurements were obtained: (1) lumen area (LA), (2) stent area (SA), (3) area delimited by the external elastic membrane (EEMA), (4) percent neointimal area calculated as (SA-LA/SA)x100, and (5) percent residual plaque area calculated as (EEMA-SA)/EEMAx100. Volume measurements within the stented segments were calculated by applying Simpson’s rule. In the pooled data analysis of 876 cross sections, linear regression showed a significant positive correlation between percent residual plaque area and percent neointimal area (r=0.50, y= 45.03+0.29x, P<0.01). There was significant incremental increase in mean percent neointimal area for stepwise increase in percent residual plaque area. Mean percent neointimalarea was 16.3+/-10.3% for lesions with a percent residual plaque area of/=50% (P<0.001). The volumetric analysis showed that the percent residual plaque volume was significantly greater in restenotic lesions compared with nonrestenotic lesions (58.7+/-4.3% versus 51.4+/-5.7%, respectively; Por = 50% diameter stenosis at follow-up, follow-up percent diameter stenosis [DS]and follow-up minimal lumen diameter [MLD]) were determined.
RESULTS: Three variables were the most consistent predictors of the follow-up angiographic findings: ostial lesion location, IVUS preinterventional lesion site plaque burden (plaque/total arterial area) and IVUS assessment of final lumen dimensions (whether final lumen area or final MLD). All three variables predicted both the primary (binary restenosis) and secondary (follow-up MLD and follow-up DS) end points. In addition, a number of variables predicted one or more but not all the end points: 1) restenosis (IVUS preinterventional lumen and arterial area); 2) follow-up DS (QCA lesion length); and 3) follow-up MLD (QCA lesion length and preinterventional MLD and DS and IVUS preinterventional lumen and arterial area).
CONCLUSIONS: Ostial lesion location and IVUS preinterventional plaque burden and postinterventional lumen dimensions were the most consistent predictors of angiographic in-stent restenosis.
AD Intravascular Ultrasound Imaging Laboratory, Washington Hospital Center, DC, USA.
AU Serruys PW, Kay IP, Disco C, Deshpande NV, de Feyter PJ
SO J Am Coll Cardiol. 1999;34(4):1067.
OBJECTIVES: We aimed to identify periprocedural quantitative coronary angiographic (QCA) variables that have predictive value on long-term angiographic results and to construct multivariate models using these variables for postprocedural prognosis.
BACKGROUND: Coronary stent implantation has reduced the restenosis rate significantly as compared with balloon angioplasty in short de novo lesions in coronary arteries>3 mm in size. Although the postprocedural minimal luminal diameter (MLD) is known to have significant bearing on long-term angiographic results, no practically useful model exists for prediction of angiographic outcome based on the periprocedural QCA variables.
METHODS: The QCA data from patients who underwent Palmaz-Schatz stent implantation for short (3 mm and completed six months of angiographic follow-up in the four prospective clinical trials (BENESTENT I, BENESTENT II pilot, BENESTENT II and MUSIC) were pooled. Multiple models were constructed using multivariate analysis. The Hosmer-Lemeshow goodness-of-fit test was used to identify the model of best fit, and this model was used to construct a reference chart for prediction of angiographic outcome on the basis of periprocedural QCA variables.
RESULTS: Univariate analysis performed using QCA variables revealed that vessel size, MLD before and after the procedure, reference area before and after the procedure, minimal luminal cross-sectional area before and after the procedure, diameter stenosis after the procedure, area of plaque after the procedure and area stenosis after the procedure were significant predictors of angiographic outcome. Using multivariate analysis, the Hosmer-Lemeshow goodness-of-fit test showed that the model containing percent diameter stenosis after the procedure and vessel size best fit the data. A reference chart was then developed to calculate the expected restenosis rate.
CONCLUSIONS: Restenosis rate after stent implantation for short lesions can be predicted using the variables percent diameter stenosis after the procedure and vessel size. This meta-analysis indicates that the concept of “the bigger the better” holds true for coronary stent implantation. Applicability of the model beyond short lesions should be tested.
AD Department of Interventional Cardiology, Thoraxcenter, Academisch Ziekenhuis, Rotterdam, The Netherlands. Serruys@card.azr.nl
AU Singh M, Gersh BJ, McClelland RL, Ho KK, Willerson JT, Penny WF, Holmes DR Jr
SO Circulation. 2004;109(22):2727.
BACKGROUND: Restenosis prediction from published studies is hampered by inadequate sample size and incomplete angiographic follow-up. The prediction of restenosis with the existing variables is poor. The aim of the present study was to include the clinical and angiographic variables commonly associated with angiographic restenosis and develop a prediction model for restenosis from the PRESTO database.
METHODS AND RESULTS: This study included 1312 patients with a single lesion enrolled in the angiographic substudy of the PRESTO trial. We constructed 2 risk scores. The first used preprocedural variables (female gender, vessel size [4 mm], lesion length>20 mm, diabetes, smoking status, type C lesion, any previous percutaneous coronary intervention [PCI], and unstable angina) derived from previous studies. Estimated restenosis rates and corresponding variability for each possible level of the resultant risk score were obtained via bootstrapping techniques. The area under the receiver-operator characteristic (ROC) curve was 0.63, indicating modest discriminatory abilityto predict restenosis. The second approach constructed a multiple logistic regression model considering significant univariate clinical and angiographic predictors of restenosis identified from the PRESTO database (treated diabetes mellitus, nonsmoker, vessel size, lesion length, American College of Cardiology/American Heart Association type C lesion, ostial location, and previous PCI). The area under the ROC curve for this risk score was also 0.63.
CONCLUSIONS: The preprocedural clinical and angiographic variables from available studies and from the PRESTO trial have only modest predictive ability for restenosis after PCI.
AD Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minn 55905, USA.
AU Mauri L, O’Malley AJ, Cutlip DE, Ho KK, Popma JJ, Chauhan MS, Baim DS, Cohen DJ, Kuntz RE
SO Am J Cardiol. 2004;93(11):1340.
The choice of drug-eluting versus bare metal stents is based on costs and expectations of restenosis and thrombosis risk. Approaches to stent placement vary from covering just the zone of maximal obstruction to stenting well beyond the lesion boundaries (normal-to-normal vessel). The independent effects of stented lesion length, nonstented lesion length, and excess stent length, on coronary restenosis have not been evaluated for bare metal or drug-eluting stents. We analyzed the angiographic follow-up cohort (1,181 patients) from 6 recent bare metal stent trials of de novo lesions in native coronary arteries. Stent length exceeded lesion length in 87% of lesions (mean lesion length 12.4 +/- 6.3 mm, mean stent length 20.0 +/- 7.9 mm, mean difference 7.6 +/- 7.9 mm). At 6- to 9-month follow-up, the mean percent diameter stenosis was 39.1 +/- 20.1%. In an adjusted multivariable model of percent diameter stenosis, each 10 mm of stented lesion length was associated with an absolute increase in percent diameter stenosis of 7.7% (p<0.0001), whereas each 10 mm of excess stent length independently increased percent diameter stenosis by 4.0% (p<0.0001) and increased target lesion revascularization at 9 months (odds ratio 1.12, 95% confidence interval 1.02 to 1.24). Significant nonstented lesion length was uncommon (12.5% of cases). In summary, stent length exceeded lesion length in most stented lesions, and the amount of excess stent length increased the risk of restenosis independent of the stented lesion length. This analysis supports a conservative approach of matching stent length to lesion length to reduce the risk of restenosis with bare metal stents.
AD Division of Clinical Biometrics, Brigham&Women’s Hospital, 1620 Tremont Street, Boston, MA 02120, USA.
AU Mauri L, Orav EJ, O’Malley AJ, Moses JW, Leon MB, Holmes DR Jr, Teirstein PS, Schofer J, Breithardt G, Cutlip DE, Kereiakes DJ, Shi C, Firth BG, Donohoe DJ, Kuntz RE
SO Circulation. 2005;111(3):321.
BACKGROUND: Observed rates of restenosis after drug-eluting stenting are low (or =32% relative increase in power,>or =24% absolute increase for late loss between 0.2 and 0.6 mm).
CONCLUSIONS: Late loss is monotonically related to restenosis risk in published stent trials. It is a generalizable and powerful angiographic end point in early or small trials of new drug-eluting stents.
AD Brigham and Women’s Hospital and Harvard Medical School, Boston, Mass 02116, USA. lmauri1@partners.org
AU Mauri L, Orav EJ, Candia SC, Cutlip DE, Kuntz RE
SO Circulation. 2005;112(18):2833.
BACKGROUND: Binary angiographic and clinical restenosis rates can vary widely between clinical studies, even for the same stent, influenced heavily by case-mix covariates that differ among observational and randomized trials intended to assess a given stent system. We hypothesized that mean in-stent late loss might be a more stable estimator of restenosis propensity across such studies.
METHODS AND RESULTS: In 46 trials of drug-eluting and bare-metal stenting, increasing mean late loss was associated with higher target lesion revascularization (TLR) rates (P<0.001). When the class of bare-metal stents was compared with the class of effective drug-eluting stents, late loss was more discriminating than TLR as measured by the high intraclass correlation coefficient (rho) (late loss, rho=0.71 versus TLR, rho=0.22; 95% CI of difference=0.33, 0.65). When the individual drug-eluting stents and bare-metal stents were compared, late loss was a better discriminator than TLR (0.68 versus 0.19; 95% CI of difference=0.24, 0.60). Greater adjustments of study covariates are needed to stabilize assessments of TLR compared with late loss because of greater influence of reference vessel diameter on TLR than on in-stent late loss. Optimization of late loss with the use of a novel method ofstandardization according to diabetes prevalence and mean lesion length resulted in minor adjustments in late loss (<0.08 mm for 90% of reported trials) and an ordered array of mean late loss values for the stent systems studied.
CONCLUSIONS: Late loss is more reliable than restenosis rates for discriminating restenosis propensity between new drug-eluting stent platforms across studies and might be the optimum end point for evaluating drug-eluting stents in early, nonrandomized studies.
AD Brigham and Women’s Hospital, Boston, MA 02116, USA. lmauri1@partners.org
AU Moses JW, Leon MB, Popma JJ, Fitzgerald PJ, Holmes DR, O’Shaughnessy C, Caputo RP, Kereiakes DJ, Williams DO, Teirstein PS, Jaeger JL, Kuntz RE, SIRIUS Investigators
SO N Engl J Med. 2003;349(14):1315.
BACKGROUND: Preliminary reports of studies involving simple coronary lesions indicate that a sirolimus-eluting stent significantly reduces the risk of restenosis after percutaneous coronary revascularization.
METHODS: We conducted a randomized, double-blind trial comparing a sirolimus-eluting stent with a standard stent in 1058 patients at 53 centers in the United States who had a newly diagnosed lesion in a native coronary artery. The coronary disease in these patients was complex because of the frequent presence of diabetes (in 26 percent of patients), the high percentage of patients with longer lesions (mean, 14.4 mm), and small vessels (mean, 2.80 mm). The primary end point was failure of the target vessel (a composite of death from cardiac causes, myocardial infarction, and repeated percutaneous or surgical revascularization of the target vessel) within 270 days.
RESULTS: The rate of failure of the target vessel was reduced from 21.0 percent with a standard stentto 8.6 percent with a sirolimus-eluting stent (P<0.001)–a reduction that was driven largely by a decrease in the frequency of the need for revascularization of the target lesion (16.6 percent in the standard-stent group vs. 4.1 percent in the sirolimus-stent group, P<0.001). The frequency of neointimal hyperplasia within the stent was also decreased in the group that received sirolimus-eluting stents, as assessed by both angiography and intravascular ultrasonography. Subgroup analyses revealed a reduction in the rates of angiographic restenosis and target-lesion revascularization in all subgroups examined.
CONCLUSIONS: In this randomized clinical trial involving patients with complex coronary lesions, the use of a sirolimus-eluting stent had a consistent treatment effect, reducing the rates of restenosis and associated clinical events in all subgroups analyzed.
AD Cardiovascular Research Foundation and Lenox Hill Heart and Vascular Institute of New York, New York 10021, USA. jmoses@lenoxhill.net
AU Stone GW, Ellis SG, Cox DA, Hermiller J, O’Shaughnessy C, Mann JT, Turco M, Caputo R, Bergin P, Greenberg J, Popma JJ, Russell ME, TAXUS-IV Investigators
SO N Engl J Med. 2004;350(3):221.
BACKGROUND: Restenosis after coronary stenting necessitates repeated percutaneous or surgical revascularization procedures. The delivery of paclitaxel to the site of vascular injury may reduce the incidence of neointimal hyperplasia and restenosis.
METHODS: At 73 U.S. centers, we enrolled 1314 patients who were receiving a stent in a single, previously untreated coronary-artery stenosis (vessel diameter, 2.5 to 3.75 mm; lesion length, 10 to 28 mm) in a prospective, randomized, double-blind study. A total of 652 patients were randomly assigned to receive a bare-metal stent, and 662 to receive an identical-appearing, slow-release, polymer-based, paclitaxel-eluting stent. Angiographic follow-up was prespecified at nine months in 732 patients.
RESULTS: In terms of base-line characteristics, the two groups were well matched. Diabetes mellitus was present in 24.2 percent of patients; the mean reference-vessel diameter was 2.75 mm, and the mean lesion length was 13.4 mm. A mean of 1.08 stents (length, 21.8 mm) were implantedper patient. The rate of ischemia-driven target-vessel revascularization at nine months was reduced from 12.0 percent with the implantation of a bare-metal stent to 4.7 percent with the implantation of a paclitaxel-eluting stent (relative risk, 0.39; 95 percent confidence interval, 0.26 to 0.59; P<0.001). Target-lesion revascularization was required in 3.0 percent of the group that received a paclitaxel-eluting stent, as compared with 11.3 percent of the group that received a bare-metal stent (relative risk, 0.27; 95 percent confidence interval, 0.16 to 0.43; P<0.001). The rate of angiographic restenosis was reduced from 26.6 percent to 7.9 percent with the paclitaxel-eluting stent (relative risk, 0.30; 95 percent confidence interval, 0.19 to 0.46; P<0.001). The nine-month composite rates of death from cardiac causes or myocardial infarction (4.7 percent and 4.3 percent, respectively) and stent thrombosis (0.6 percent and 0.8 percent, respectively) were similar in the group that received a paclitaxel-eluting stent and the group that received a bare-metal stent.
CONCLUSIONS: As compared with bare-metal stents, the slow-release, polymer-based, paclitaxel-eluting stent is safe and markedly reduces the rates of clinical and angiographic restenosis at nine months.
AD Cardiovascular Research Foundation and Lenox Hill Heart and Vascular Institute, New York 10022, USA. gstone@crf.org
AU Cohen DJ, Doucet M, Cutlip DE, Ho KK, Popma JJ, Kuntz RE
SO Circulation. 2001;104(7):773.
BACKGROUND: Recent studies have suggested that smokers may require less frequent repeated revascularization after percutaneous coronary intervention (PCI) compared with nonsmokers. However, the mechanism of this phenomenon is unknown.
METHODS AND RESULTS: We examined the association between smoking and restenosis using pooled data from 8671 patients treated with PCI in 9 multicenter clinical trials. Clinical restenosis was examined in the cohort of 5682 patients who were assigned to clinical follow-up only. Angiographic restenosis was evaluated in the subset of 2989 patients who were assigned to mandatory angiographic restudy. Among those patients assigned to clinical follow-up only, target lesion revascularization (TLR) occurred in 6.6% of smokers and 10.1% of nonsmokers (P<0.001). After adjustment for baseline clinical and angiographic differences, the rate of TLR remained significantly lower in smokers with an adjusted relative risk of 0.69 (95% CI, 0.54 to 0.88). Among the angiographic cohort, there were no differences in the rates of angiographic restenosis or follow-up diameter stenosis in either univariate or multivariate analyses. This dissociation between clinical and angiographic restenosis was explained in part by reduced sensitivity to restenosis on the part of smokers and by the greater reluctance of smokers to seek medical attention despite recurrent angina.
CONCLUSIONS: In patients undergoing contemporary PCI, cigarette smoking is associated with a lower rate of subsequent TLR without affecting angiographic restenosis. These findings have important implications for the follow-up of smokers after PCI and suggest that cross-study comparisons of rates of clinical restenosis must account for the potential confounding effect of smoking.
AD Harvard Clinical Research Institute, Harvard Medical School, Boston, MA, USA. djc@hsph.harvard.edu
AU Violaris AG, Thury A, Regar E, Melkert R, Serruys PW
SO Heart. 2000;84(3):299.
OBJECTIVES: To assess the influence of smoking on restenosis after coronary angioplasty.
DESIGN AND PATIENTS: The incidence of smoking on restenosis was investigated in 2948 patients. They were prospectively enrolled in four major restenosis trials in which quantitative angiography was used before and immediately after successful angioplasty and again at six months.
RESULTS: Within the study population there were 530 current smokers, 1690 ex-smokers, and 728 non-smokers. Smokers were more likely to be men (85.9% v 87. 5% v 65.3%, current v ex- v non-, p<0.001), to be younger (54.0 (9. 0) v 57.0 (9.1) v 59.9 (9.4) years, p<0.001), to have peripheral vascular disease (7.2% v 5.5% v 2.3%, p<0.001), and have sustained a previous myocardial infarction (42.9% v 43.9% v 37.9%, p = 0.022), but were less likely to be diabetic (9.1% v 9.5% v 12.6%, p = 0.043) or hypertensive (24.9% v 29.3% v 37.2, p50% diameter stenosis) at six months (35.28% v 35.33% v 37.09%, current v ex- v non-), or the absolute loss (0.29 (0.54) v 0.33 (0.52) v 0. 35(0.55) mm, respectively; p = 0.172).
CONCLUSIONS: Although smokers have a lower incidence of known predisposing risk factors for atherosclerosis, they require coronary intervention almost six years earlier than non-smokers and three years earlier than ex-smokers. Once they undergo successful coronary angioplasty, there appears to be no evidence that smoking influences their short term (six month) outcome, but because of the known long term effects of smoking, patients should still be encouraged to discontinue the habit.
AD Academic Cardiology Unit, St Mary’s Hospital, London W2, UK.
AU Pache J, Kastrati A, Mehilli J, Schühlen H, Dotzer F, Hausleiter J, Fleckenstein M, Neumann FJ, Sattelberger U, Schmitt C, Müller M, Dirschinger J, Schömig A
SO J Am Coll Cardiol. 2003;41(8):1283.
OBJECTIVES: We tested the hypothesis that thinner-strut stents are associated with a reduced rate of restenosis when comparing two stents with different design.
BACKGROUND: We have previously shown that, for two stents with similar design, the risk for restenosis is dependent on the strut thickness. It is unknown whether strut thickness preserves its relevance as a determinant of restenosis even in the presence of different stent designs.
METHODS: A total of 611 patients with symptomatic coronary artery disease were randomly assigned to receive either the thin-strut ACS RX Multilink stent (Guidant, Advanced Cardiovascular Systems, Santa Clara, California) (strut thickness 50 microm, interconnected ring design; n = 309) or the thick-strut BX Velocity stent (Cordis Corp., Miami, Florida) (strut thickness 140 microm, closed cell design; n = 302). The primary end point was angiographic restenosis (>or =50% diameter stenosis at follow-up angiography). Secondary end points were the incidence of target-vessel revascularization (TVR) and the combined rate of death and myocardial infarction (MI) at one year.
RESULTS: The incidence of angiographic restenosis was 17.9% in the thin-strut group and 31.4% in the thick-strut group, relative risk, 0.57 (95% confidence interval, 0.39 to 0.84), p<0.001. A TVR due to restenosis was required in 12.3% of the thin-strut group and 21.9% of the thick-strut group, relative risk, 0.56 (95% confidence interval, 0.38 to 0.84), p = 0.002. No significant difference was observed in the combined incidence of death and MI at one year.
CONCLUSIONS: When two stents with different design are compared, the stent with thinner struts elicits less angiographic and clinical restenosis than the thicker-strut stent.
AU Yoshitomi Y, Kojima S, Yano M, Sugi T, Matsumoto Y, Saotome M, Tanaka K, Endo M, Kuramochi M
SO Am Heart J. 2001;142(3):445.
BACKGROUND: Experimental studies have revealed that stent configuration influences intimal hyperplasia. The purpose of this study was to evaluate clinical outcomes for 2 stent designs in a randomized trial with quantitative coronary angiography (QCA) and intravascular ultrasonography (IVUS).
METHODS: We randomly assigned 100 patients with 107 lesions and symptomatic coronary artery disease to deployment of a Multilink stent (Advanced Cardiovascular Systems, Guidant, Santa Clara, Calif) or a GFX stent (Applied Vascular Engineering, Santa Rosa, Calif) with IVUS guidance. QCA and IVUS studies were performed before and after intervention and at follow-up (4.2 +/- 1.0 months).
RESULTS: There were no significant differences in baseline characteristics and QCA and IVUS parameters before and after intervention between the 2 groups. However, minimal lumen diameter at follow-up was significantly larger in the Multilink group (2.46 +/- 0.59 vs 2.08 +/- 0.79 mm, P<.05). Maximal in-stent intimal hyperplasia was significantly larger in the GFX group (2.9 +/- 1.7 vs 1.8 +/- 1.2 mm(2), P<.01). The restenosis rate differed between the 2 groups (Multilink 4% vs GFX 26%, P =.003). In multiple stepwise logistic regression analysis, the only predictor that significantly correlated with restenosis was stent type (P<.01). The odds ratio for the GFX stent-treated vessels was 18.65 (95% confidence interval 2.10-165.45).
CONCLUSIONS: With deployment of the GFX stent, a thicker neointima develops within the stent. Stent configuration may affect clinical outcomes.
AD Division of Cardiology, Tohsei National Hospital, Shizuoka, Japan. ytommy@sage.ocn.ne.jp
AU Castagna MT, Mintz GS, Leiboff BO, Ahmed JM, Mehran R, Satler LF, Kent KM, Pichard AD, Weissman NJ
SO Am Heart J. 2001;142(6):970.
OBJECTIVES: Serial intravascular ultrasonographic (IVUS) studies have shown that in-stent restenosis is the result of intimal hyperplasia (IH). However, routine preintervention IVUS imaging has suggested that many restenotic stents were inadequately deployed. The purpose of this IVUS study was to determine the incidence of mechanical problems contributing to in-stent restenosis (ISR).
METHODS: Between April 1994 and June 2000, 1090 patients with ISR were treated at the Washington Hospital Center. All underwent preintervention IVUS imaging. IVUS measurements included proximal and distal reference lumen areas and diameters; stent, minimum lumen, and IH (stent minus lumen) areas; and IH burden (IH/stent area).
RESULTS: In 49 ISR lesions (4.5%), there were morphologic findings that contributed to the restenosis. These were termed mechanical complications. Examples include (1) missing the lesion (eg, an aorto-ostial stenosis), (2) stent “crush,” and (3) havingthe stent stripped off the balloon during the implantation procedure. Excluding mechanical complications, stent underexpansion was common. In 20% of the ISR cases the stents had a cross-sectional area (CSA) at the site of the lesion<80% of the average reference lumen area. Twenty percent of lesions had a minimum stent area<5.0 mm(2) and an additional 18% had a minimum stent area of 5.0 to 6.0 mm(2). Twenty-four percent of lesions had an IH burden<60%.
CONCLUSION: Mechanical problems related to stent deployment procedures contribute to a significant minority of ISR lesions (approximately 25%).
AD Intravascular Ultrasound Imaging and Cardiac Catheterization Laboratories, Cardiovascular Research Institute, Washington Hospital Center, Washington, DC 20010, USA.
AU Ellis SG, Vandormael MG, Cowley MJ, DiSciascio G, Deligonul U, Topol EJ, Bulle TM
SO Circulation. 1990;82(4):1193.
To assess the likelihood of procedural success in patients with multivessel coronary disease undergoing percutaneous coronary angioplasty, 350 consecutive patients (1,100 stenoses) from four clinical sites were evaluated. Eighteen variables characterizing the severity and morphology of each stenosis and 18 patient-related variables were assessed at a core angiographic laboratory and at the clinical sites. Most patients had Canadian Cardiovascular Society class III or IV angina (72%) and two-vessel coronary disease (78%). Left ventricular function was generally well preserved (mean ejection fraction, 58 +/- 12%; range, 18-85%) and 1.9 +/- 1.0 stenoses per patient had attempted percutaneous coronary angioplasty. Procedural success (less than or equal to 50% final diameter stenosis in one or more stenoses and no major ischemic complications) was achieved in 290 patients (82.8%), and an additional nine patients (2.6%) had a reduction in diameter stenosis by 20% or more with a final diameter stenosis 51-60% and were without major complications. Major ischemic complications (death, myocardial infarction, or emergency bypass surgery) occurred in 30 patients (8.6%). In-hospital mortality was 1.1%. Stepwise regression analysis determined that a modified American College of Cardiology/American Heart Association Task Force (ACC/AHA) classification of the primary target stenosis (with type B prospectively divided into type B1 [one type B characteristic]and type B2 [greater than or equal to two type B characteristics]) and the presence of diabetes mellitus were the only variables independently predictive of procedural outcome (target stenosis modified ACC/AHA score; p less than 0.001 for both success and complications; diabetes mellitus: p = 0.003 for success and p = 0.016 for complications). Analysis of success and complications on a per stenosis dilated basis showed, for type A stenoses, a 92% success and a 2% complication rate; for type B1 stenoses, an 84% success and a 4% complication rate; for type B2 stenoses, a 76% success and a 10% complication rate; and for type C stenoses, a 61% success and a 21% complication rate. The subdivision into types B1 and B2 provided significantly more information in this clinically important intermediate risk group than did the standard ACC/AHA scheme. The stenosis characteristics of chronic total occlusion, high grade (80-99% diameter) stenosis, stenosis bend of more than 60 degrees, and excessive tortuosity were particularly predictive of adverse procedural outcome. This improved scheme may improve clinical decision making and provide a framework on which to base meaningful subgroup analysis in randomized trials assessing the efficacy of percutaneous coronary angioplasty.
AD Division of Cardiology, University of Michigan Medical Center, Ann Arbor 48109-0022.
AU Kastrati A, Schömig A, Elezi S, Dirschinger J, Mehilli J, Schühlen H, Blasini R, Neumann FJ
SO Circulation. 1999;100(12):1285.
Background-The modified American College of Cardiology/American Heart Association (ACC/AHA) lesion morphology criteria are predictive of early outcome after various coronary catheter interventions. Their potential prognostic value after stent implantation and, in particular, for restenosis and long-term clinical outcome has not been studied. We assessed the prognostic value of the modified ACC/AHA criteria for the long-term angiographic and clinical outcome of patients after coronary stenting. Methods and Results-This study includes 2944 consecutive patients with symptomatic coronary artery disease treated with coronary stent placement. Modified ACC/AHA lesion morphology criteria were used to qualitatively assess the angiograms; type A and B1 lesions were categorized as simple, and type B2 and C lesions were designated complex. Primary end points were angiographic restenosis and 1-year event-free survival. Restenosis rate was 33.2% in complex lesions and 24.9% in simple lesions (P<0.001). It was 21. 7% for type A, 26.3% for type B1, 33.7% for type B2, and 32.6% for type C lesions. One-year event-free survival was 75.6% for patients with complex lesions and 81.1% for patients with simplelesions (P50% by QCA. IVUS predictors were minimum and mean in-stent area, stent length, and in-stent diameter. Multiple models were constructed with multivariate logistic regression analysis. The model containing minimum in-stent area and stent length best fit the Hosmer-Lemeshow goodness-of-fit test. This model was used to construct a reference chart to calculate the expected 6-month restenosis rate.
CONCLUSIONS: The expected 6-month in-stent restenosis rate after stent implantation for short lesions in relatively large vessels can be predicted by use of in-stent minimal area (which is inversely related to restenosis) and stent length (which is directly related to restenosis), both of which can be read from a simple reference chart.
AD University Hospital Rotterdam-Dijkzigt, Rotterdam, Netherlands.
AU Kastrati A, Schömig A, Elezi S, Schühlen H, Wilhelm M, Dirschinger J
SO Circulation. 1998;97(24):2396.
BACKGROUND: Little is known about the behavior with regard to restenosis of multiple lesions within the same patient treated with intracoronary stenting. Our objective was to test the hypothesis that there is an intrapatient dependence of restenosis between lesions.
METHODS AND RESULTS: Quantitative analysis was carried out on angiograms obtained before, immediately after, and at 6 months after coronary stent placement in 1734 lesions in 1244 patients. We used a specialized logistic regression that not only accounts for intraclass correlation but also quantifies it in the form of odds ratio (OR) as the change in risk of a lesion to develop restenosis if another companion lesion had restenosis. The model was based on 23 patient- and lesion-related variables with binary restenosis (diameter stenosis>or =50%) as end point. The overall restenosis rate was 27.5%: 24.4% for single-lesion, 28.6% for double-lesion, and 33.8% for>or =3-lesion interventions. After adjustment for the influence of significant factors (hypercholesterolemia, systemic arterial hypertension, diabetes mellitus, previous PTCA, ostial lesion, location in left anterior descending coronary artery, number of stents placed, vessel size, stenosis severity, balloon-to-vessel ratio, and final result), the analysis found a significant intrapatient correlation, OR 2.5 (1.8 to 3.6). This means that in patients with multilesion interventions, the risk of a lesion to develop restenosis is 2.5 times higher if a companion lesion has restenosis, independently of the presence or absence of analyzed patient risk factors (eg, diabetes).
CONCLUSIONS: This study demonstrates that there is a dependence of restenosis between coronary lesions in patients who undergo a multilesion intervention. The likelihood of restenosis for a lesion is higher when another companion lesion has also developed restenosis. Other, as yet unidentified patient factors may be the source of this intrapatient correlation of restenosis.
AD Deutsches Herzzentrum and 1. Medizinische Klinik rechts der Isar, Technische Universität München, Munich, Germany. kastrati@dhm.mhn.de
AU Best PJ, Lennon R, Ting HH, Bell MR, Rihal CS, Holmes DR, Berger PB
SO J Am Coll Cardiol. 2002;39(7):1113.
OBJECTIVES: We sought to determine the effect of varying degrees of renal insufficiency on death and cardiac events during and after a percutaneous coronary intervention (PCI).
BACKGROUND: Patients with end-stage renal disease have a high mortality from coronary artery disease. Little is known about the impact of mild and moderate renal insufficiency on clinical outcomes after PCI.
METHODS: Cardiac mortality and all-cause mortality were determined for 5,327 patients undergoing PCI from January 1, 1994, to August 31, 1999, at the Mayo Clinic, based on the estimated creatinine clearance or whether the patient was on dialysis.
RESULTS: In-hospital mortality was significantly associated with renal insufficiency (p = 0.001). Even after successful PCI, one-year mortality was 1.5% when the creatinine clearance was>or =70 ml/min (n = 2,558), 3.6% when it was 50 to 69 ml/min (n = 1,458), 7.8% when it was 30 to 49ml/min (n = 828) and 18.3% when it was<30 ml/min (n = 141). The 18.3% mortality rate for the group with<30 ml/min creatinine clearance was similar to the 19.9% mortality rate in patients on dialysis (n = 46). The mortality risk was largely independent of all other factors.
CONCLUSIONS: Renal insufficiency is a strong predictor of death and subsequent cardiac events in a dose-dependent fashion during and after PCI. Patients with renal insufficiency have more baseline cardiovascular risk factors, but renal insufficiency is associated with an increased risk of death and other adverse cardiovascular events, independent of all other measured variables.
AD Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
AU Gruberg L, Weissman NJ, Waksman R, Laird JR Jr, Pinnow EE, Wu H, Deible R, Kent KM, Pichard AD, Satler LF, Lindsay J Jr
SO Am J Cardiol. 2002;89(1):54.
Recent studies have shown that patients with mild chronic renal insufficiency (CRI) have a high prevalence of cardiovascular disease and cardiac death. Furthermore, patients with CRI undergoing percutaneous coronary intervention have a higher rate of in-hospital and long-term morbidity and mortality. A recent retrospective subgroup analysis of patients with CRI undergoing percutaneous intervention suggests that the use of stents may improve their in-hospital and long-term outcomes.
AD Cardiac Catheterization Laboratory and the Cardiovascular Research Institute, Washington Hospital Center, Washington, DC 20010, USA. gruberg67@hotmail.com
AU Taniwaki M, Stefanini GG, Silber S, Richardt G, Vranckx P, Serruys PW, Buszman PE, Kelbaek H, Windecker S, The RESOLUTE All Comers Investigators
SO J Am Coll Cardiol. 2014;
OBJECTIVE: To investigate 4-year outcomes and predictors of repeat revascularization in patients treated with Resolute™zotarolimus-eluting stent (R-ZES) and XIENCE V™everolimus-eluting stent (EES) in the RESOLUTE All Comers trial.
BACKGROUND: Data on long-term outcomes of new generation drug-eluting stents are limited, and predictors of repeat revascularization due to restenosis and/or progression of disease are largely unknown.
METHODS: Patients were randomly assigned to treatment with R-ZES (n=1,140) or EES (n=1,152). We assessed pre-specified safety and efficacy outcomes at 4 years including target-lesion failure (TLF) and stent thrombosis (ST). Predictors of revascularization at 4 years were identified by Cox regression analysis.
RESULTS: At 4 years, rates of TLF (15.2% vs. 14.6%, p=0.68), cardiac death (5.4% vs. 4.7%, p=0.44), target-vessel myocardial infarction (MI) (5.3% vs. 5.4%, p=1.00), clinically-indicated target-lesion revascularization (TLR) (7.0% vs. 6.5%, p=0.62), and definite/probable ST (2.3% vs. 1.6%, p=0.23) were similar with R-ZES and EES. Independent predictors of TLR were: age, insulin-treated diabetes, SYNTAX score, treatment of saphenous vein grafts, ostial lesions, and instent restenosis. Independent predictors of any revascularization were: age, diabetes, previous PCI, ST-elevation MI, smaller reference vessel diameter, SYNTAX score, and treatment of left anterior descending, right coronary artery, saphenous vein grafts, ostial lesions, or instent restenosis.
CONCLUSIONS: R-ZES and EES demonstrated similar safety and efficacy throughout 4 years. TLR represented less than half of all repeat revascularization procedures. Patient and lesion-related factors predicting the risk of TLR and any revascularization showed considerable overlap.
CLINICAL TRIAL INFO: RESOLUTE All Comers; NCT00617084.
AU Chen MS, John JM, Chew DP, Lee DS, Ellis SG, Bhatt DL
SO Am Heart J. 2006;151(6):1260.
BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) has been thought to present in a stable manner as exertional angina. However, the presentation of in-stent restenosis (ISR) is not well-studied. We hypothesized that a substantial proportion of bare metal ISR presents as acute coronary syndromes. We aimed to characterize the severity of the clinical presentation of ISR.
METHODS: We searched our PCI database for all cases of PCI for bare metal ISR occurring between May 1999 and September 2003. Multivessel interventions were excluded. In-stent restenosis presentation was classified into three categories: (1) myocardial infarction (MI), (2) unstable angina requiring hospitalization before angiography, and (3) exertional angina. Routine angiographic screening after initial stent placement was not performed, so ISR episodes were clinical, rather than angiographic, ISR.
RESULTS: We identified 1186 cases of bare metal ISR in 984 patients. Median age was 63, 72% were male, and 36% had diabetes. Of the ISR episodes, 9.5% presented as acute MI (7.3% as non-ST-segment elevation MI and 2.2% as ST-segment elevation MI), 26.4% as unstable angina requiring hospitalization before angiography, and 64.1% as exertional angina.
CONCLUSIONS: More than one third of bare metal ISR episodes presented as MI or unstable angina requiring hospitalization. The acuity of the clinical presentation of bare metal ISR appears to be more severe than has been previously thought. Aggressive efforts, such as drug-eluting stents to decrease the incidence of unstable angina due to bare metal ISR, are warranted.
AD The Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
AU Bossi I, Klersy C, Black AJ, Cortina R, Choussat R, Cassagneau B, Jordan C, Laborde JC, Laurent JP, Bernies M, Fajadet J, Marco J
SO J Am Coll Cardiol. 2000;35(6):1569.
OBJECTIVES: We sought to evaluate the long-term clinical outcome of patients undergoing successful balloon angioplasty for in-stent restenosis, and to determine correlates of the need for subsequent target lesion revascularization (TLR).
BACKGROUND: In-stent restenosis can be safely treated by repeat percutaneous intervention. Reported subsequent TLR rates have varied from 20% to 80% and seem related to the type of restenotic lesion.
METHODS: The study population comprised 234 patients with follow-up data who were successfully treated with repeat balloon angioplasty for in-stent restenosis in 257 lesions between May 1995 and January 1998 at our institution.
RESULTS: Clinical follow-up was available at 459 (286 to 693) days after the repeat procedure. Event-free survival was 78.5% and 74.6% at 12 and 24 months, respectively. Recurrent events occurred in 58patients (24.8%), including 6 deaths (2.6%), 4 myocardial infarction (1.7%) and repeat target vessel revascularization in 50 patients (21.4%). Independent predictors of repeat TLR were time to in-stent restenosis<90 days (Hazard ratio 4.67, p<0.001), minimal luminal diameter after repeat procedure (Hazard ratio 0.38, p = 0.034) and the angiographic pattern of in-stent restenosis (Hazard ratio 1.65, p = 0.036).
CONCLUSIONS: Balloon angioplasty is an effective means of treating in-stent restenosis. The long-term results are acceptable particularly for focal restenotic lesions. Further restenosis is more common in patients with early initial recurrence, more proliferative lesions and a poorer angiographic result from repeat angioplasty.
AD Unitéde Cardiologie Interventionelle, Clinique Pasteur, Toulouse, France. marco@interv-cardio-toul.com
AU Walters DL, Harding SA, Walsh CR, Wong P, Pomerantsev E, Jang IK
SO Am J Cardiol. 2002;89(5):491.
Coronary stents have been the major advancement in percutaneous coronary intervention in the last decade and are used in 60% to 80% of patients. However, in-stent restenosis continues to be a problem, occurring in 20% to 30% of cases. The clinical presentation of patients who develop restenosis after stenting has not been well characterized. In this study we compared the clinical presentation of in-stent restenosis with that of restenosis without stenting. Of 739 patients who underwent percutaneous coronary intervention and had repeat catheterization between October 1, 1997, and June 30, 2000, 262 consecutive patients with recurrent ischemia and restenosis were identified: 191 patients with (group A) and 71 without (Group B) stenting. Patients who underwent interventions in bypass grafts and those who developed early acute stent thrombosis were excluded from the study. Recurrent clinical ischemia occurred at a mean of 5.5 months in group A and 6.5 months in group B (p = 0.24). Rest angina (Braunwald class II and III) was more frequent in group A (48% vs 32%, p = 0.032). Acute coronary syndromes, the combination of rest angina, and acute myocardial infarction were also more frequent in group A (68% vs 46%, p = 0.03). Patients in group A were more likely to have angiographically visible thrombus than those in group B (9% vs 0%, p = 0.02). Thus, acute coronary syndromes are a common clinical presentation of restenosis among patients whose follow-up angiogram is obtained for clinical reasons, and occur more frequently in patients with in-stent restenosis than in those with restenosis without stenting.
AD Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
AU Mishkel GJ, Moore AL, Markwell S, Shelton MC, Shelton ME
SO J Am Coll Cardiol. 2007;49(2):181.
OBJECTIVES: The purpose of this study was to examine the outcomes of patients who developed coronary in-stent restenosis (ISR) or stent thrombosis (STH) inside drug-eluting stents (DES).
BACKGROUND: Drug-eluting stents have markedly reduced the incidence of restenosis. However, when restenosis occurs within a DES, its optimal management remains unclear.
METHODS: We retrospectively analyzed clinical and angiographic data from 92 patients who underwent revascularization for ISR (n = 84) or STH (n = 8) within a DES at our institution. Regular follow-ups were available up to 2 years. We recorded the occurrence of major adverse cardiac events (MACE), defined as deaths from all causes, myocardial infarction (MI), or target lesion revascularization (TLR), among patients treated by the “DES sandwich” technique or by other treatment methods.
RESULTS: In-hospital MACE included 1 periprocedural MI and 2 deaths. Over a mean follow-up of 15 +/- 6 months, the overall rates of death, MI, and TLR were 8.7%, 2.2%, and 30.6%, respectively. By actuarial analysis, the 12-month TLR and MACE rates were 28.2% and 42.9%, respectively.
CONCLUSIONS: Current treatments of ISR or STH in DES are associated with a high long-term rate of MACE.
AD Prairie Heart Institute at St. John’s Hospital, Springfield, Illinois 62794, USA.
AU Fineschi M, Gori T, Pierli C, Casini S, Sinicropi G, Buti A, Iadanza A, Bravi A
SO Can J Cardiol. 2007;23(2):139.
BACKGROUND: Limited information is available regarding restenosis after implantation of a sirolimus-eluting stent (SES).
OBJECTIVE: To report on angiographic characteristics, clinical presentation and treatment of this particularly complex type of coronary lesion.
METHODS AND RESULTS: A total of 1424 SES were implanted in 1159 patients (average 1.2 per patient) for chronic or acute coronary syndromes in the University Hospital of Siena (Siena, Italy), which is a tertiary centre. Symptomatic in-SES restenosis was observed in 26 patients (2.2%) at 10+/-5 months (median eight months, range four to 23 months) following the initial intervention. In-SES restenosis was associated with stable angina in 16 patients, acute myocardial infarction in three patients and unstable angina in seven patients. Two patients had restenosis in two separate SES. Conditions often associated with in-SES restenosis included treatment of chronic total occlusion, geographic miss or in-stent restenosis during the index procedure. Among the first 20 patients, those with focal, in-body SES (type Ic) restenosisreceived balloon-only angioplasty, and patients with other patterns received repeat SES implantation. Clinical and angiographic follow-up (average 16+/-7 months) recorded one death (noncardiac) in the balloon-only group and four cases of unstable angina (three due to relapsing in-SES restenosis in the balloon-only group and the fourth due to a de novo lesion). Follow-up quantitative angiography showed a higher incidence of binary restenosis after balloon-only treatment (57% versus 17%; P<0.05), as well as higher lumen loss and loss index (Por =10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16+/-7 mm. Balloon diameter of2.98+/-0.37 mm and maximal inflation pressure of 10+/-3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19+/-0.60 mm vs. 1.75+/-0.68 mm (p=0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p=0.046.
CONCLUSIONS: Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.
AD Department of Cardiology, Hôpital Charles Nicolle, University of Rouen, France.
AU Bauters C, Banos JL, Van Belle E, Mc Fadden EP, Lablanche JM, Bertrand ME
SO Circulation. 1998;97(4):318.
BACKGROUND: In-stent restenosis is an increasing clinical problem. Discordant results have been published regarding the risk of recurrent restenosis after repeat angioplasty for the treatment of in-stent restenosis.
METHODS AND RESULTS: One hundred three consecutive patients (107 vessels) underwent repeat percutaneous intervention for the treatment of in-stent restenosis and were entered in a prospective angiographic follow-up program. Repeat balloon angioplasty was performed at 93 lesions (87%) and additional stenting at 14 lesions (13%). The primary success rate was 98%. Six-month angiographic follow-up was performed in 85% of eligible patients. Restenosis was determined by quantitative angiography. Restenosis defined as a>50% diameter stenosis at follow-up was observed at 22% of lesions. The rate of target-lesion revascularization at 6 months was 17%. Repeat intervention for diffuse in-stent restenosis and severe stenosis before repeat intervention were associated with significantly higher rates of recurrent restenosis.
CONCLUSIONS: The overall restenosis rate after repeat intervention for in-stent restenosis is low. Thesubgroup of patients with diffuse and/or severe in-stent restenosis, however, is at higher risk of recurrent restenosis and may benefit from alternative therapeutic strategies.
AD Service de Cardiologie B, Hôpital Cardiologique, Lille, France.
AU Alfonso F, Zueco J, Cequier A, Mantilla R, Bethencourt A, López-Minguez JR, Angel J, AugéJM, Gómez-Recio M, Morís C, Seabra-Gomes R, Perez-Vizcayno MJ, Macaya C, Restenosis Intra-stent: Balloon Angioplasty Versus Elective Stenting (RIBS) Investigators
SO J Am Coll Cardiol. 2003;42(5):796.
OBJECTIVES: This randomized trial compared repeat stenting with balloon angioplasty (BA) in patients with in-stent restenosis (ISR).
BACKGROUND: Stent restenosis constitutes a therapeutic challenge. Repeat coronary interventions are currently used in this setting, but the recurrence risk remains high.
METHODS: We randomly assigned 450 patients with ISR to elective stent implantation (224 patients) or conventional BA (226 patients). Primary end point was recurrent restenosis rate at six months. Secondary end points included minimal lumen diameter (MLD), prespecified subgroup analyses, and a composite of major adverse events.
RESULTS: Procedural success was similar in both groups, but in-hospital complications were more frequent in the balloon group. After the procedure MLD was larger in the stent group (2.77 +/- 0.4 vs. 2.25 +/- 0.5 mm, por =3 mm) the restenosis rate (27% vs. 49%, p = 0.007) and the event-free survival (84% vs. 62%, p = 0.002) were better after repeat stenting.
CONCLUSIONS: In patients with ISR, repeat coronary stenting provided better initial angiographic results but failed to improve restenosis rate and clinical outcome when compared with BA. However, in patients with large vessels coronary stenting improved the long-term clinical and angiographic outcome.
AD Unidad de Hemodinámica, Servicio de Cardiología Intervencionista, Instituto Cardiovascular, University Hospital San Carlos, Ciudad Universitaria, Plaza de Cristo Rey, Madrid 28040, Spain. falf@hotmail.com
AU Alfonso F, AugéJM, Zueco J, Bethencourt A, López-Mínguez JR, Hernández JM, Bullones JA, Calvo I, Esplugas E, Pérez-Vizcayno MJ, Moreno R, Fernández C, Hernández R, Gama-Ribeiro V, RIBS Investigators
SO J Am Coll Cardiol. 2005;46(5):756.
OBJECTIVES: We sought to analyze the very late outcomes of patients treated for in-stent restenosis (ISR) according to treatment allocation and 10 prespecified variables.
BACKGROUND: Long-term results (>2 years) of patients with ISR undergoing repeat coronary interventions are not well established.
METHODS: The Restenosis Intrastent: Balloon angioplasty versus elective Stenting (RIBS) randomized study compared these two strategies in 450 patients with ISR. A detailed systematic protocol was used for late clinical follow-up.
RESULTS: At one-year follow-up (100% of patients), the event-free survival was similar in the two groups (77% stent implantation [ST]arm, 71% balloon angioplasty [BA]arm, log-rank p = 0.19). Additional long-term clinical follow-up (median 4.3 years, range 3 to5 years) was obtained in 98.6% of patients. During this time 22 additional patients died (9 ST arm, 13 BA arm), 7 suffered a myocardial infarction (3 ST arm, 4 BA arm), 23 required coronary surgery (11 ST arm, 12 BA arm), and 9 underwent repeat coronary interventions (4 ST arm, 5 BA arm) (nonexclusive events). At four years the event-free survival was 69% in the ST arm and 64% in the BA arm (log-rank p = 0.21). Among the 10 prespecified variables, vessel size>or = 3 mm had a major influence on the clinical outcome at four years, with better results in the ST group (hazard ratio 0.51, 95% confidence interval 0.3 to 0.89, p = 0.016).
CONCLUSIONS: Patients with ISR undergoing repeat interventions have a significant event rate at late follow-up. Continued medical surveillance should be continued after one year. Patients with large vessels have a better outcome after repeat stenting.
AD University Hospital Clinico San Carlos, Madrid, Spain. falf@hotmail.com
AU Mehran R, Dangas G, Abizaid A, Lansky AJ, Mintz GS, Pichard AD, Satler LF, Kent KM, Waksman R, Stone GW, Leon MB
SO Am Heart J. 2001;141(4):610.
BACKGROUND: Although both percutaneous transluminal coronary angioplasty (PTCA) and additional stenting can be used for the treatment for focal in-stent restenosis (ISR), no large-scale comparative data on the clinical outcomes after these interventional procedures have been reported.
METHODS: In the current study we compared the in-hospital and long-term clinical results of PTCA alone (n = 266 patients, n = 364 lesions) versus stenting (n = 135 patients, n = 161 lesions) for the treatment of focal ISR, defined as a lesion length less than or equal to 10 mm.
RESULTS: There were significantly more diabetic patients in the PTCA group than in the stent group (36% vs 26%, P =.04), but other baseline characteristics were similar. Lesion length and preprocedure minimal lumen diameter (MLD) were also similar in the two groups, but the stent group had a larger reference vessel diameter (3.40 +/- 0.73 mm vs 2.99 +/- 0.68 mm, P<.001). Stenting achieved a larger postprocedure MLD than PTCA did (2.95 +/- 0.95 mm vs 2.23 +/- 0.60 mm, P5 times normal was more frequent with stent (18.5% vs 9.7%, P =.05). At 1 year the two interventional strategies had similar cumulative mortality (4.6% PTCA vs 5.1% stent, P not significant) and target lesion revascularization rate (24.6% PTCA vs 26.5% stent, P not significant). By multivariate analysis, the sole predictor of target lesion revascularization was diabetes (odds ratio 2.4, 95% confidence intervals 1.2-4.7, P =.01).
CONCLUSION: Repeat stenting for the treatment of focal ISR had a higher postprocedure creatine kinase myocardial band elevation rate and similar long-term clinical results compared with PTCA alone.
AD Cardiovascular Research Foundation, 55 E 59th St., New York, NY 10022, USA.
AU Sousa JE, Costa MA, Abizaid A, Sousa AG, Feres F, Mattos LA, Centemero M, Maldonado G, Abizaid AS, Pinto I, Falotico R, Jaeger J, Popma JJ, Serruys PW
SO Circulation. 2003;107(1):24.
BACKGROUND: We have previously reported the safety and effectiveness of sirolimus-eluting stents for the treatment of de novo coronary lesions. The present investigation explored the potential of this technology to treat in-stent restenosis.
METHODS AND RESULTS: Twenty-five patients with in-stent restenosis were successfully treated with the implantation of 1 or 2 sirolimus-eluting Bx VELOCITY stents in São Paulo, Brazil. Nine patients received 2 stents (1.4 stents per lesion). Angiographic and volumetric intravascular ultrasound (IVUS) images were obtained after the procedure and at 4 and 12 months. All vessels were patent at the time of 12-month angiography. Angiographic late loss averaged 0.07+/-0.2 mm in-stent and -0.05+/-0.3 mm in-lesion at 4 months, and 0.36+/-0.46 mm in-stent and 0.16+/-0.42 mm in-lesion after 12 months. No patient had in-stent or stent margin restenosis at 4 months, and only one patient developed in-stent restenosis at 1-year follow-up. Intimal hyperplasia by 3-dimensional IVUS was 0.92+/-1.9 mm(3) at 4 months and 2.55+/-4.9 mm(3) after 1 year. Percent volume obstruction was 0.81+/-1.7% and 1.76+/-3.4% at the 4- and 12-month follow-up, respectively. There was no evidence of stent malapposition either acutely or in the follow-up IVUS images, and there were no deaths, stent thromboses, or repeat revascularizations.
CONCLUSION: This study demonstrates the safety and the potential utility of sirolimus-eluting Bx VELOCITY stents for the treatment of in-stent restenosis.
AD Institute Dante Pazzanese of Cardiology, São Paulo, Brazil. jesousa@uol.com.br
AU Degertekin M, Regar E, Tanabe K, Smits PC, van der Giessen WJ, Carlier SG, de Feyter P, Vos J, Foley DP, Ligthart JM, Popma JJ, Serruys PW
SO J Am Coll Cardiol. 2003;41(2):184.
OBJECTIVES: In this study, we assess the value of sirolimus eluting stent (SES) implantation in patients with complex in-stent restenosis (ISR).
BACKGROUND: The treatment of ISR remains a therapeutic challenge, since many pharmacological and mechanical approaches have shown disappointing results. The SESs have been reported to be effective in de-novo coronary lesions.
METHODS: Sixteen patients with severe, recurrent ISR in a native coronary artery (average lesion length 18.4 mm) and objective evidence of ischemia were included. They received one or more 18 mm Bx VELOCITY SESs (Cordis Waterloo, Belgium). Quantitative angiographic and three-dimensional intravascular ultrasound (IVUS) follow-up was performed at four months, and clinical follow-up at nine months.
RESULTS: The SES implantation (n = 26) was successful in all 16 patients. Four patients had recurrent restenosis following brachytherapy, and three patients had totally occluded vessels preprocedure. At four months follow-up, one patient had died and three patients had angiographic evidence of restenosis (one in-stent and two in-lesion). In-stent late lumen loss averaged 0.21 mm and the volume obstruction of the stent by IVUS was 1.1%. At nine months clinical follow-up, three patients had experienced four major adverse cardiac events (two deaths and one acute myocardial infarction necessitating repeat target vessel angioplasty).
CONCLUSIONS: The SES implantation in patients with severe ISR lesions effectively prevents neointima formation and recurrent restenosis at four months angiographic follow-up.
AD Thoraxcenter, University Hospital Rotterdam, The Netherlands.
AU Tanabe K, Serruys PW, Grube E, Smits PC, Selbach G, van der Giessen WJ, Staberock M, de Feyter P, Müller R, Regar E, Degertekin M, Ligthart JM, Disco C, Backx B, Russell ME
SO Circulation. 2003;107(4):559.
BACKGROUND: The first clinical study of paclitaxel-eluting stent for de novo lesions showed promising results. We performed the TAXUS III trial to evaluate the feasibility and safety of paclitaxel-eluting stent for the treatment of in-stent restenosis (ISR).
METHODS AND RESULTS: The TAXUS III trial was a single-arm, 2-center study that enrolled 28 patients with ISR meeting the criteria of lesion lengthor =50%) at 6-month follow-up angiography based on “in-segment” analysis. Primary analysis was comparison between stent groups and balloon angioplasty groups; a secondary analysis compared sirolimus and paclitaxel stents.
RESULTS: Follow-up angiography was performed in 275 (92%) of 300 patients. The incidence of angiographic restenosis was 44.6% (41/92) in the balloon angioplasty group, 14.3% (13/91) in the sirolimus stent group (P<.001 vs balloon angioplasty), and 21.7% (20/92) in the paclitaxel stent group (P = .001 vs balloon angioplasty). When compared with balloon angioplasty, receiving a sirolimus stent had a relative risk (RR) of angiographic restenosis of 0.32 (95% confidence interval [CI], 0.18-0.56); a paclitaxel stent had an RR of 0.49 (95% CI, 0.31-0.76). The incidence of target vessel revascularization was 33.0% (33/100) in the balloon angioplasty group, 8.0% (8/100) in the sirolimus stent group (P<.001 vs balloon angioplasty), and 19.0% (19/100) in the paclitaxel stent group (P = .02 vs balloon angioplasty). The secondary analysis showed a trend toward a lower rate of angiographic restenosis (P = .19) and a significantly lower rate of target vessel revascularization (P = .02) among sirolimus stent patients compared with paclitaxel stent patients.
CONCLUSIONS: In patients with in-stent restenosis, a strategy based on sirolimus- or paclitaxel-eluting stents is superior to conventional balloon angioplasty for the prevention of recurrent restenosis. Sirolimus-eluting stents may be superior to paclitaxel-eluting stents for treatment of this disorder.
AD Deutsches Herzzentrum, Technische Universität, Munich, Germany. kastrati@dhm.mhn.de
AU Alfonso F, Pérez-Vizcayno MJ, Hernandez R, Bethencourt A, MartíV, López-Mínguez JR, Angel J, Mantilla R, Morís C, Cequier A, SabatéM, Escaned J, Moreno R, Bañuelos C, Suárez A, Macaya C, RIBS-II Investigators
SO J Am Coll Cardiol. 2006;47(11):2152.
OBJECTIVES: We sought to assess the effectiveness of sirolimus-eluting stents (SES) in patients with in-stent restenosis (ISR).
BACKGROUND: Treatment of patients with ISR remains a challenge.
METHODS: The Restenosis Intrastent: Balloon Angioplasty Versus Elective Sirolimus-Eluting Stenting (RIBS-II) study is a multicenter randomized trial conducted in 150 patients with ISR (76 allocated to SES and 74 to balloon angioplasty [BA]). The primary end point was recurrent restenosis rate at nine months. Secondary end points included prespecified subgroup analysis, lumen volume on intravascular ultrasound (IVUS), and a composite of major clinical events at one year.
RESULTS: Angiographic success was obtained in all patients. At 9-month angiographic follow-up (96% of eligible patients) minimal lumen diameter was larger (2.52 mm [interquartile range (IQR) 2.09 to 2.81]vs. 1.54 mm [IQR 0.91 to 2.05]; p<0.001) and recurrent restenosis rate was lower (11% vs. 39%; p<0.001) in the SES group. Prespecified subgroup analyses were consistent with the main outcome measure. Lumen volume on IVUS at 9 months was also larger (279 mm3 [IQR 227 to 300]vs. 197 mm3 [IQR 177 to 230]; p<0.001) in the SES group. At one-year clinical follow-up (100% of patients), the event-free survival (freedom from death, myocardial infarction, and target vessel revascularization) was significantly improved in the SES group (88% vs. 69%; p<0.004) as the result of a lower requirement for target vessel revascularization (11% vs. 30%; p<0.003).
CONCLUSIONS: In patients with ISR, the use of SES provides superior long-term clinical, angiographic, and IVUS outcome than BA treatment.
AD Clinico San Carlos University Hospital, Madrid, Spain. falf@hotmail.com
AU Migliorini A, Shehu M, Carrabba N, Giurlani L, Valenti R, Buonamici P, Dovellini EV, Parodi G, Antoniucci D
SO Am J Cardiol. 2005;96(8):1110.
Few data are available on the effectiveness of sirolimus-eluting stent implantation for the treatment of in-stent restenosis, and no data exist about the predictors of outcome after sirolimus-eluting stent implantation for complex in-stent restenosis (diffuse, proliferative, or total occlusion). From April 2002 to May 2004, 136 patients with 161 complex in-stent restenoses underwent sirolimus-eluting stent implantation. At 9 months, 5 patients had died (3 of cardiac and 2 of noncardiac causes), no reinfarctions had occurred, and 11 target vessel revascularization procedures had been performed. The target vessel revascularization rate was 8%, and the in-segment binary restenosis rate was 17%. The predictors of the risk of recurrence were unstable angina as the clinical presentation of in-stent restenosis, an ostial location of the target lesion, lesion length, and sirolimus-eluting stent diameter<or =2.5 mm.
AD Division of Cardiology, Careggi Hospital, Florence, Italy.
AU Liistro F, Fineschi M, Grotti S, Angioli P, Carrera A, Ducci K, Gori T, Falsini G, Pierli C, Bolognese L
SO J Am Coll Cardiol. 2010;55(7):613.
OBJECTIVES: The aim of this study was to evaluate the long-term clinical outcome of the efficacy and safety of sirolimus-eluting stents (SES) for in-stent restenosis (ISR) in the TRUE (Tuscany Registry of Unselected In-Stent Restenosis) database.
BACKGROUND: The TRUE registry demonstrated that SES in the treatment of bare-metal stent ISR is efficacious (5% of target lesion revascularization [TLR]) and safe (stent thrombosis<1%) at 9 months. Clinical outcome at 4 years is reported.
METHODS: A total of 244 patients with ISR who were treated with SES implantation represent the study population. The incidence of major adverse cardiac events was collected at 4 years.
RESULTS: At 4-year follow-up, overall mortality was 9.8% (24 patients). Cardiac death occurred in 11 (4.5%), nonfatal myocardial infarction in 8 (3.2%), and TLR in 27 (11.1%) patients for a cumulative event-free survival rate of 80.3%. Definite stent thrombosis occurred in 5 (2%) patients and possible stent thrombosis in 2 (0.8%). Diabetes remained an independent negative predictor of freedom from TLR (odds ratio [OR]: 0.38; 95% confidence interval [CI]: 0.20 to 0.71, p = 0.002) and major adverse cardiac events (OR: 0.38; 95% CI: 0.20 to 0.71, p = 0.002).
CONCLUSIONS: The clinical benefit of SES implantation for bare-metal stent ISR is maintained at 4 years with a low TLR rate and an overall incidence of stent thrombosis of 0.7% per year.
AD Cardiovascular Department, San Donato Hospital, Arezzo, Italy. francescoliistro@hotmail.com
AU Smith SC Jr, Feldman TE, Hirshfeld JW Jr, Jacobs AK, Kern MJ, King SB 3rd, Morrison DA, O’Neill WW, Schaff HV, Whitlow PL, Williams DO, Antman EM, Smith SC Jr, Adams CD, Anderson JL, Faxon DP, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Jacobs AK, Nishimura R, Ornato JP, Page RL, Riegel B, American College of Cardiology/American Heart Association Task Force on Practice Guidelines, ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention
SO J Am Coll Cardiol. 2006;47(1):e1.
The ACC/AHA ST-Elevation and Non–ST-Elevation Myocardial Infarction (STEMI/NSTEMI) Performance Measures Writing Committee was charged with the development of performance measures concerning the diagnosis and treatment of both ST-elevation myocardial infarction (STEMI) and non–ST-elevation myocardial infarction (NSTEMI) (see the Methodology section for detailed information on how the measures were constructed and selected.)
A Scope of the Problem
Both STEMI and NSTEMI afflict an enormous number of people each year. The estimated incidence of myocardial infarction (MI) is 865 000 attacks annually. Twenty percent of men and 30% of women will die within 1 year after having an initial recognized MI. The risk of further cardiac disease complications, such as another heart attack, sudden death, angina pectoris, heart failure and stroke for those who survive an MI is substantial (2).
Over the past 30 years, advances in cardiovascular care have resulted in a dramatic decline in mortality and morbidity associated with STEMI and NSTEMI (3). However, there is strong evidence that the best treatments and strategies for these patients are not always pursued. As a result, the outcomes of STEMI and NSTEMI patients are not as good as they could be with better translation of the best scientific knowledge to the bedside.
A Definition of STEMI/NSTEMI
The Writing Committee has incorporated the use of the terms STEMI and NSTEMI throughout this document along with the all-inclusive term acute myocardial infarction (AMI) based on the revision of the 1999 ACC/AHA Guideline for the Management of Patients with Acute Myocardial Infarction (4). This guideline update resulted in the topic of AMI being separated into two guidelines: the ACC/AHA 2002 Guideline Update for the Management of Patients With Unstable Angina and Non–ST-Segment Elevation Myocardial Infarction (5) and the 2004 ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction (6). The Writing Committee has used the term AMI when the measure refers to both STEMI and NSTEMI patients, while the term STEMI was used in cases in which the clinical recommendation is specific to STEMI patients only. Measures specific to NSTEMI patients only are not contained in this set but may be considered in future updates.
Specific diagnosis codes, based on ICD-9-CM (Table 1),should be used to screen and select the inpatient target patient population. These codes correspond to the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and Centers for Medicare and Medicaid services (CMS) AMI cohort selection codes.
AU Silber S, Albertsson P, Avilés FF, Camici PG, Colombo A, Hamm C, Jørgensen E, Marco J, Nordrehaug JE, Ruzyllo W, Urban P, Stone GW, Wijns W, Task Force for Percutaneous Coronary Interventions of the European Society of Cardiology
SO Eur Heart J. 2005;26(8):804.
In patients with stable CAD, PCI can be considered a valuable initial mode of revascularization in all patients with objective large ischaemia in the presence of almost every lesion subset, with only one exception: chronic total occlusions that cannot be crossed. In early studies, there was a small survival advantage with CABG surgery compared with PCI without stenting. The addition of stents and newer adjunctive medications improved the outcome for PCI. The decision to recommend PCI or CABG surgery will be guided by technical improvements in cardiology or surgery, local expertise, and patients’ preference. However, until proved otherwise, PCI should be used only with reservation in diabetics with multi-vessel disease and in patients with unprotected left main stenosis. The use of drug-eluting stents might change this situation. Patients presenting with NSTE-ACS (UA or NSTEMI) have to be stratified first for their risk of acute thrombotic complications. A clear benefit from early angiography (<48 h) and, when needed, PCI or CABG surgery has been reported only in the high-risk groups. Deferral of intervention does not improve outcome. Routine stenting is recommended on the basis of the predictability of the result and its immediate safety. In patients with STEMI, primary PCI should be the treatment of choice in patients presenting in a hospital with PCI facility and an experienced team. Patients with contra-indications to thrombolysis should be immediately transferred for primary PCI, because this might be their only chance for quickly opening the coronary artery. In cardiogenic shock, emergency PCI for complete revascularization may be life-saving and should be considered at an early stage. Compared with thrombolysis, randomized trials that transferred the patients for primary PCI to a ‘heart attack centre’ observed a better clinical outcome, despite transport times leading to a significantly longer delay between randomization and start of the treatment. The superiority of primary PCI over thrombolysis seems to be especially clinically relevant for the time interval between 3 and 12 h after onset of chest pain or other symptoms on the basis of its superior preservation of myocardium. Furthermore, with increasing time to presentation, major-adverse-cardiac-event rates increase after thrombolysis, but appear to remain relatively stable after primary PCI. Within the first 3 h after onset of chest pain or other symptoms, both reperfusion strategies seem equally effective in reducing infarct size and mortality. Therefore, thrombolysis is still a viable alternative to primary PCI, if it can be delivered within 3 h after onset of chest pain or other symptoms. Primary PCI compared with thrombolysis significantly reduced stroke. Overall, we prefer primary PCI over thrombolysis in the first 3 h of chest pain to prevent stroke, and in patients presenting 3-12 h after the onset of chest pain, to salvage myocardium and also to prevent stroke. At the moment, there is no evidence to recommend facilitated PCI. Rescue PCI is recommended, if thrombolysis failed within 45-60 min after starting the administration. After successful thrombolysis, the use of routine coronary angiography within 24 h and PCI, if applicable, is recommended even in asymptomatic patients without demonstrable ischaemia to improve patients’ outcome. If a PCI centre is not available within 24 h, patients who have received successful thrombolysis with evidence of spontaneous or inducible ischaemia before discharge should be referred to coronary angiography and revascularized accordingly–independent of ‘maximal’ medical therapy.
AD Kardiologische Praxis und Praxisklinik, München, Germany. sigmund@silber.com
AU Kushner FG, Hand M, Smith SC Jr, King SB 3rd, Anderson JL, Antman EM, Bailey SR, Bates ER, Blankenship JC, Casey DE Jr, Green LA, Hochman JS, Jacobs AK, Krumholz HM, Morrison DA, Ornato JP, Pearle DL, Peterson ED, Sloan MA, Whitlow PL, Williams DO
SO J Am Coll Cardiol. 2009;54(23):2205.
A primary challenge in the development of clinical practice guidelines is keeping pace with the stream of new data on which recommendations are based. In an effort to respond promptly to new evidence, the American College of Cardiology Foundation/American Heart Association (ACCF/AHA) Task Force on Practice Guidelines has created a “focused update” process to revise the existing guideline recommendations that are affected by evolving data or opinion. Before the initiation of this focused approach, periodic updates and revisions of existing guidelines required up to 3 years to complete. Now, however, new evidence will be reviewed in an ongoing fashion to more efficiently respond to important science and treatment trends that could have a major impact on patient outcomes and quality of care. Evidence will be reviewed at least twice a year, and updates will be initiated on an as-needed basis as quickly as possible, while maintaining the rigorous methodology that the ACCF and AHA have developed during their 25 years of partnership.
These updated guideline recommendations reflect a consensus of expert opinion after a thorough review primarily of late-breaking clinical trials identified through a broad-based vetting process as being important to the relevant patient population, as well as a review of other new data deemed to have an impact on patient care (see Section 1.1, Methodology and Evidence Review, for details). This focused update is not intended to represent an update based on a full literature review from the date of the previous guideline publication.
AD Department of Cardiology, Columbia University Medical Center and the Cardiovascular Research Foundation, New York, NY 10032, USA. gs2184@columbia.edu
AU Stone GW, Ellis SG, O’Shaughnessy CD, Martin SL, Satler L, McGarry T, Turco MA, Kereiakes DJ, Kelley L, Popma JJ, Russell ME, TAXUS V ISR Investigators
SO JAMA. 2006;295(11):1253.
CONTEXT: Restenosis within bare-metal stents is often treated with repeat percutaneous coronary intervention, although subsequent recurrence rates are high, with vascular brachytherapy (VBT) affording the best results. The effectiveness of drug-eluting stents in this setting has not been established.
OBJECTIVE: To investigate the safety and efficacy of the polymer-based, slow-release paclitaxel-eluting stent in patients with restenotic lesions after prior stent implantation in native coronary arteries.
DESIGN, SETTING, AND PATIENTS: Prospective, multicenter, randomized trial conducted between June 6, 2003, and July 16, 2004, at 37 North American academic and community-based institutions in 396 patients with in-stent restenosis of a previously implanted bare-metal coronary stent (vessel diameter, 2.5-3.75 mm; lesion length,<or =46 mm).
INTERVENTIONS: Patients were randomly assigned to undergo angioplasty followed by VBT with a beta source (n = 201) or paclitaxel-eluting stent implantation (n = 195). Clinical and angiographic follow-up at 9 months was scheduled in all patients.
MAIN OUTCOME MEASURE: Ischemia-driven target vessel revascularization at 9 months.
RESULTS: Diabetes mellitus was present in 139 patients (35.1%). Median reference vessel diameter was 2.65 mm and median lesion length was 15.3 mm. In the VBT group, new stents were implanted in 22 patients (10.9%) and in the paclitaxel-eluting stent group, multiple stents were required in 57 patients (29.2%), with median stent length of 24 mm. Follow-up at 9 months was complete in 194 patients in the VBT group and 191 patients in the paclitaxel-eluting stent group (96.5% and 97.9%, respectively). For VBT and paclitaxel-eluting stents, respectively, the number of events and 9-month rates for ischemic target lesion revascularization were 27 (13.9%) vs 12 (6.3%) (relative risk [RR], 0.45; 95% confidence interval [CI], 0.24-0.86; P = .01); for ischemic target vessel revascularization, 34 (17.5%) vs 20 (10.5%) (RR, 0.60; 95% CI, 0.36-1.00; P = .046); and for overall major adverse cardiac events, 39 (20.1%) vs 22 (11.5%) (RR, 0.57; 95% CI, 0.35-0.93; P = .02), with similar rates of cardiac death or myocardial infarction (10 [5.2%]vs 7 [3.7%]; RR, 0.71; 95% CI, 0.28-1.83; P = .48) and target vessel thrombosis (5 [2.6%]vs 3 [1.6%]; RR, 0.61; 95% CI, 0.15-2.50; P = .72). Angiographic restenosis at 9 months was 31.2% (53 of 170 patients) with VBT and 14.5% (25 of 172 patients) with paclitaxel-eluting stents (RR, 0.47; 95% CI, 0.30-0.71; P<.001).
CONCLUSION: Treatment of bare-metal in-stent restenotic lesions with paclitaxel-eluting stents rather than angioplasty followed by VBT reduces clinical and angiographic restenosis at 9 months and improves event-free survival.
AD Department of Cardiology, Columbia University Medical Center and the Cardiovascular Research Foundation, New York, NY 10032, USA. gs2184@columbia.edu
AU Ellis SG, O’Shaughnessy CD, Martin SL, Kent K, McGarry T, Turco MA, Kereiakes DJ, Popma JJ, Friedman M, Koglin J, Stone GW, TAXUS V ISR Investigators
SO Eur Heart J. 2008;29(13):1625.
AIMS: This study sought to investigate the 2-year outcomes of patients treated with the paclitaxel-eluting TAXUS((R)) stent (PES) or vascular brachytherapy (VBT), the previous ‘gold standard therapy’, for bare metal stent in-stent restenosis (ISR).
METHODS AND RESULTS: In the TAXUS V-ISR trial, 396 patients with bare metal stent ISR referred for percutaneous coronary intervention were prospectively randomized to either PES or beta source VBT. The present analysis reports 24-month clinical outcomes from that study. Between 9 and 24 months, ischaemia-driven target lesion revascularization tended to be required less frequently with assignment to PES compared to VBT (5.3 vs. 10.3%, P = .07). As a result, ischaemia-driven target lesion revascularization at 24 months was significantly reduced with PES compared with VBT (10.1 vs. 21.6%, P = 0.003), as was ischaemia-driven target vessel revascularization (18.1 vs. 27.5%, P = .03). There were no significant differences between the two groups with regard to death, myocardial infarction, or target vessel thrombosis either between 12 and 24 months, or cumulative to 24 months.
CONCLUSION: Freedom from clinical restenosis at 2 years is significantly enhanced after PES placement compared with VBT for bare metal stent ISR, with similar rates of death, myocardial infarction, and target vessel thrombosis.
AD Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, F25, Cleveland, OH 44195, USA. elliss@ccf.org
AU Holmes DR Jr, Teirstein P, Satler L, Sketch M, O’Malley J, Popma JJ, Kuntz RE, Fitzgerald PJ, Wang H, Caramanica E, Cohen SA, SISR Investigators
SO JAMA. 2006;295(11):1264.
CONTEXT: Although vascular brachytherapy is the only approved therapy for restenosis following bare-metal stent implantation, drug-eluting stents are now being used. Data on the relative merits of each are limited.
OBJECTIVE: To determine the safety and efficacy of the sirolimus-eluting stent compared with vascular brachytherapy for the treatment of patients with restenosis within a bare-metal stent.
DESIGN, SETTING, AND PATIENTS: Prospective, multicenter, randomized trial of 384 patients with in-stent restenosis who were enrolled between February 2003 and July 2004 at 26 academic and community medical centers. Data presented represent all follow-up as of June 30, 2005.
INTERVENTIONS: Vascular brachytherapy (n = 125) or the sirolimus-eluting stent (n = 259).
MAIN OUTCOME MEASURE: Target vessel failure (cardiac death, myocardial infarction, or target vessel revascularization) at 9 months postprocedure.
RESULTS: Baseline patient characteristics were well matched. Lesion length was similar between vascular brachytherapy and sirolimus-eluting stent patients (mean [SD], 16.76 [8.55]mm vs 17.22 [7.97]mm, respectively; P = .61). Procedural success was 99.2% (124/125) in the vascular brachytherapy group and 97.3% (250/257) in the sirolimus-eluting stent group (P = .28). The rate of target vessel failure was 21.6% (27/125) with vascular brachytherapy and 12.4% (32/259) with the sirolimus-eluting stent (relative risk [RR], 1.7; 95% confidence interval [CI], 1.1-2.8; P = .02). Target lesion revascularization was required in 19.2% (24/125) of the vascular brachytherapy group and 8.5% (22/259) of the sirolimus-eluting stent group (RR, 2.3 [95% CI, 1.3-3.9]; P = .004). At follow-up angiography, the rate of binary angiographic restenosis for the analysis segment was 29.5% (31/105) for the vascular brachytherapy group and 19.8% (45/227) for the sirolimus-eluting stent group (RR, 1.5 [95% CI, 1.0-2.2]; P = .07). Compared with the vascular brachytherapy group, minimal lumen diameter was larger in the sirolimus-eluting stent group at 6-month follow-up (mean [SD], 1.52 [0.63]mm vs 1.80 [0.63]mm; P<.001), reflecting greater net lumen gain in the analysis segment (0.68 [0.60]vs 1.0 [0.61]mm; P<.001) due to stenting and no edge restenosis.
CONCLUSION: Sirolimus-eluting stents result in superior clinical and angiographic outcomes compared with vascular brachytherapy for the treatment of restenosis within a bare-metal stent.
The greatest recent mechanical advance in percutaneous coronary revascularization (PCR) has been the development of bare-metal stents, which compared with traditional balloon angioplasty substantially reduce angiographic restenosis and the need for repeat target vessel revascularization (TVR). Stents provide a larger arterial lumen diameter immediately postprocedure (acute gain), although their drawback is an increased reparative response of neointimal formation (late loss). Fortunately, the net gain remains greatest with stents compared with other PCR devices. In less complex lesions, the rate of TVR with bare-metal stents is approximately 10% to 15%, although this rate has been reported to be 2- to 3-fold higher in more complex lesions and unique patient subsets.1,2 In 2003, at a time when the use of bare-metal stents peaked, approximately 1 million coronary stents were placed in patients hospitalized in the United States.3 Even with a conservative estimate, this means at least 100 000 in-stent restenotic lesions occurred, making this an important clinical problem.
AU Lemos PA, van Mieghem CA, Arampatzis CA, Hoye A, Ong AT, McFadden E, Sianos G, van der Giessen WJ, de Feyter PJ, van Domburg RT, Serruys PW
SO Circulation. 2004;109(21):2500.
BACKGROUND: We evaluated the clinical and angiographic outcomes of patients presenting with restenosis after sirolimus-eluting stent (SES) implantation treated with repeated percutaneous intervention.
METHODS AND RESULTS: A total of 24 consecutive patients have undergone repeated percutaneous intervention to treat post-SES restenosis (27 lesions). The restenosis was located within the stent in 93% of lesions. From the 27 lesions, 1 (4%) was re-treated with a bare stent, 3 (11%) were treated with balloon dilatation, and the remaining 23 lesions (85%) were treated with repeated drug-eluting stent implantation (SES in 12 lesions [44%], paclitaxel-eluting stents in 11 lesions [41%]). The event-free survival rate was 70.8% after a median follow-up of 279 days from the post-SES treatment. The overall recurrent restenosis rate was 42.9%. The risk of recurrent restenosis was increased for patients with hypercholesterolemia, previous angioplasty, failed brachytherapy, post-SES restenosis needing early (<6 months) treatment, and post-SES restenosis treated with balloon dilatation. The recurrent restenosis rate of originally de novo lesions re-treated with drug-eluting stents was 18.2%.
CONCLUSIONS: Even though de novo lesions treated with SES at baseline and re-treated with drug-eluting stents had reasonably better outcomes than other lesion types and strategies, our study shows that the treatment of post-SES restenosis is currently suboptimal and warrants further investigation.
AD Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands.
AU Moussa ID, Moses JW, Kuntz RE, Holmes DR, Popma JJ, Teirstein PS, Wong SC, Leon MB
SO Am J Cardiol. 2006;97(11):1582.
Although clinical outcomes after sirolimus-eluting stents (SESs) have been previously described (“primary” success rates), the fate of patients whose SES implantation fail and who require ischemia-driven target lesion revascularization is poorly understood. The SIRIUS trial is a prospective, randomized, clinical trial that includes 533 evaluable patients with SESs. Twenty-two of these patients had adjudicated ischemia-driven target lesion revascularization (4.1%) within the first year of follow-up and comprised the study population of this analysis. Of these patients, 11 (50%) had diabetes, and restenotic lesions were focal and located at the proximal stent edge in 91% and 73% of patients, respectively. Restenosis was treated with bare metal stent implantation, balloon dilatation, or intravascular brachytherapy in 82%, 13.5%, and 4.5% of patients, respectively. At 1-year follow-up after the first recurrence (2-year follow-up after the index procedure), only 5 of these patients (23%) required a second repeat revascularization procedure. Risk factors for a second recurrence after treatment of SES restenosis were female gender, long lesions that required long stents at the index procedure, and an early first recurrence. In conclusion, SES failure treated with traditional percutaneous coronary intervention yielded good outcome at 1-year follow-up (secondary failure rate only 23%), perhaps due to the focal nature of the SES restenotic lesion. Future studies should evaluate other methods, including drug-eluting stents, to further optimize the outcome of treatment of SES failures.
AD Columbia University Medical Center-New York Presbyterian Hospital and Cardiovascular Research Foundation, New York, New York, USA. imoussa@crf.org
AU Cosgrave J, Melzi G, Biondi-Zoccai GG, Airoldi F, Chieffo A, Sangiorgi GM, Montorfano M, Michev I, Carlino M, Bonizzoni E, Colombo A
SO J Am Coll Cardiol. 2006;47(12):2399.
OBJECTIVES: We sought to determine if the angiographic pattern of in-stent restenosis in drug-eluting stents (DES) maintains its prognostic importance.
BACKGROUND: The pattern of restenosis in the bare-metal stent era had a significant impact on therapeutic outcomes.
METHODS: We identified a total of 250 consecutive restenotic lesions in 203 patients (66.4% sirolimus-eluting stents and 33.6% paclitaxel-eluting stents). We divided these lesions into two groups: focal, defined as<or =10 mm, 163 lesions (65.2%); and nonfocal, which were diffuse, proliferative, or obstructive, 87 lesions (34.8%). The end points analyzed were angiographic restenosis and target lesion revascularization (TLR).
RESULTS: Diabetes was the only clinical variable associated with the pattern of restenosis (28.8% focal compared with 52.9% diffuse; p = 0.0001). Angiographic follow-up of the treatment of restenosis was available in 61.2% of the lesions and was similar between the two groups. The rate of angiographic restenosis was 17.8% in the focal group and 51.1% in the nonfocal group (p = 0.0001). The incidence of TLR also increased with the type of restenosis treated (9.8% and 23%, respectively; p = 0.007). An adjusted multivariate analysis revealed that the pattern of restenosis remained associated with both the occurrence of restenosis and TLR (odds ratio [OR]5.1 [95% confidence interval (CI) 1.1 to 23], p = 0.03; and OR 3.61 [95% CI 1.2 to 10.9], p = 0.02; respectively).
CONCLUSIONS: Similar to bare-metal stent data, the angiographic pattern of restenosis following DES implantation is prognostically important. Diabetes is a significant predictor of the pattern of restenosis in the DES era.
AU Garg S, Smith K, Torguson R, Okabe T, Slottow TL, Steinberg DH, Roy P, Xue Z, Gevorkian N, Satler LF, Kent KM, Suddath WO, Pichard AD, Waksman R
SO Catheter Cardiovasc Interv. 2007;70(1):9.
OBJECTIVE: The authors aimed to compare the clinical outcomes with repeat drug-eluting stent (DES) implantation utilizing the same type versus an alternate DES type for in-stent restenosis (ISR) of DES.
BACKGROUND: : DES are proven as an effective treatment for bare metal ISR.
METHODS: A cohort of 116 patients previously treated with a sirolimus-eluting stent (SES) or a paclitaxel-eluting stent (PES) who presented with angiographic ISR were treated with repeat DES. Of these, 62 (53.4%) were treated with different DES and 54 (46.6%) were treated with the same DES. This cohort was followed for clinical events at 30 days, 6 months, and 1 year.
RESULTS: Baseline characteristics were similar except for more diabetes among patients receiving the different type of DES. Of the 116, overall 16.4% of the DES were implanted for previous ISR and 2.6% had previously received brachytherapy. At 6 months, the overall target vessel revascularization (TVR) rate was 12.2% for the entire cohort. The TVR-major adverse cardiac event (MACE) rate for the patients treated with different DES was 14.5% and 16.7% for the same DES (P = 0.750). Overall TVR rate at 1 year was 28.8%. The TVR-MACE was 32.6% for different DES and 35.0% for the same DES (P = 0.814).
CONCLUSIONS: Reimplantation of DES for the treatment of DES ISR (same or different) is safe but associated with a high rate of recurrences at 1 year regardless of the initial DES type. Other treatment modalities for ISR of DES should be considered to further improve the overall TVR-MACE.
AD Department of Cardiology, Washington Hospital Center, Washington, District of Columbia 20010, USA.
AU Abe M, Kimura T, Morimoto T, Taniguchi T, Yamanaka F, Nakao K, Yagi N, Kokubu N, Kasahara Y, Kataoka Y, Otsuka Y, Kawamura A, Miyazaki S, Nakao K, Horiuchi K, Ito A, Hoshizaki H, Kawaguchi R, Setoguchi M, Inada T, Kishi K, Sakamoto H, Morioka N, Imai M, Shiomi H, Nonogi H, Mitsudo K, j-Cypher Registry Investigators
SO Circulation. 2010;122(1):42.
BACKGROUND: Optimal treatment strategies for restenosis of sirolimus-eluting stents (SES) have not been adequately addressed yet.
METHODS AND RESULTS: During the 3-year follow-up of 12 824 patients enrolled in the j-Cypher registry, 1456 lesions in 1298 patients underwent target-lesion revascularization (TLR). Excluding 362 lesions undergoing TLR for stent thrombosis or TLR using treatment modalities other than SES or balloon angioplasty (BA), 1094 lesions with SES-associated restenosis in 990 patients treated with either SES (537 lesions) or BA (557 lesions) constituted the study population for the analysis of recurrent TLR and stent thrombosis after the first TLR. Excluding 24 patients with both SES- and BA-treated lesions, 966 patients constituted the analysis set for the mortality outcome. Cumulative incidence of recurrent TLR in the SES-treated restenosis lesions was significantly lower than that in the BA-treated restenosis lesions (23.8% versus 37.7% at 2 years after the first TLR; P<0.0001). Among 33 baseline variables evaluated, only hemodialysis was identified to be the independent risk factor for recurrent TLR by a multivariable logistic regression analysis. After adjusting for confounders, repeated SES implantation was associated with a strong treatment effect in preventing recurrent TLR over BA (odds ratio, 0.44; 95% confidence interval, 0.32 to 0.61; P50%) at 6- to 8-month follow-up, target lesion revascularization, the composite of death or myocardial infarction, and definite stent thrombosis at 12 months.
RESULTS: Regarding anti-restenotic efficacy, there were no differences between SES and PES in late loss (0.40 +/- 0.65 mm vs. 0.38 +/- 0.59 mm; p = 0.85), binary restenosis (19.6% vs. 20.6%; p = 0.69), or target lesion revascularization (16.6% vs. 14.6%; p = 0.52). In terms of safety outcomes, the rates of death/myocardial infarction (6.1% vs. 5.8%; p = 0.86) and stent thrombosis (0.4% vs. 0.4%; p>0.99) were also similar.
CONCLUSIONS: In cases of SES restenosis, treatment with either repeat SES or switch to PES was associated with a comparable degree of efficacy and safety. Drug resistance at an individual patient level may play a contributory role to the somewhat higher than expected late loss observed with the SES in the current study. (Intracoronary Stenting and Angiographic Results: Drug-Eluting Stents for In-Stent Restenosis 2 [ISAR-DESIRE 2]; NCT00598715).
AD Deutsches Herzzentrum, Technische Universität, Munich, Germany.
AU Scheller B, Hehrlein C, Bocksch W, Rutsch W, Haghi D, Dietz U, Böhm M, Speck U
SO N Engl J Med. 2006;355(20):2113.
BACKGROUND: Treatment of coronary in-stent restenosis is hampered by a high incidence of recurrent in-stent restenosis. We assessed the efficacy and safety of a paclitaxel-coated balloon in this setting.
METHODS: We enrolled 52 patients with in-stent restenosis in a randomized, double-blind, multicenter trial to compare the effects of a balloon catheter coated with paclitaxel (3 microg per square millimeter of balloon surface area) with those of an uncoated balloon catheter in coronary angioplasty. The primary end point was late luminal loss as seen on angiography. Secondary end points included the rates of restenosis (a binary variable) and major adverse cardiac events.
RESULTS: Multivessel disease was present in 80% of patients in both groups. Quantitative coronary angiography revealed no significant differences in baseline measures. At 6 months, angiography showed that the mean (+/-SD) in-segment late luminal loss was 0.74+/-0.86 mm in the uncoated-balloon group versus 0.03+/-0.48 mm in the coated-balloon group (P=0.002). A total of 10 of 23 patients (43%) in the uncoated-balloon group had restenosis, as compared with 1 of 22 patients (5%) in the coated-balloon group (P=0.002). At 12 months, the rate of major adverse cardiac events was 31% in the uncoated-balloon group and 4% in the coated-balloon group (P=0.01). This difference was primarily due to the need for target-lesion revascularization in six patients in the uncoated-balloon group (P=0.02).
CONCLUSIONS: Treatment of coronary in-stent restenosis with paclitaxel-coated balloon catheters significantly reduced the incidence of restenosis. These data suggest that the inhibition of restenosis by local drug delivery may not require stent implantation and sustained drug release at the site of injury. (ClinicalTrials.gov number, NCT00106587 [ClinicalTrials.gov].).
AD Universitätsklinikum des Saarlandes, Homburg/Saar, Germany. bruno.scheller@uniklinikum-saarland.de
AU Unverdorben M, Vallbracht C, Cremers B, Heuer H, Hengstenberg C, Maikowski C, Werner GS, Antoni D, Kleber FX, Bocksch W, Leschke M, Ackermann H, Boxberger M, Speck U, Degenhardt R, Scheller B
SO Circulation. 2009;119(23):2986.
BACKGROUND: Treatment of in-stent restenosis with paclitaxel-coated balloon catheter as compared with plain balloon angioplasty has shown surprisingly low late lumen loss at 6 months and fewer major adverse cardiac events up to 2 years. We compared the efficacy and safety of a paclitaxel-coated balloon with a paclitaxel-eluting stent as the current standard of care.
METHODS AND RESULTS: One hundred thirty-one patients with coronary in-stent restenosis were randomly assigned to treatment by a paclitaxel-coated balloon (3 microg/mm2) or a paclitaxel-eluting stent. The main inclusion criteria encompassed diameter stenosis of>or =70% and<or =22 mm in length, with a vessel diameter of 2.5 to 3.5 mm. The primary end point was angiographic in-segment late lumen loss. Quantitative coronary angiography revealed no differences in baseline parameters. At 6 months follow-up, in-segment late lumen loss was 0.38+/-0.61 mm in the drug-eluting stent group versus 0.17+/-0.42 mm (P=0.03) in the drug-coated balloon group, resulting in a binary restenosis rate of 12 of 59 (20%) versus 4 of 57 (7%; P=0.06). At 12 months, the rate of major adverse cardiac events were 22% and 9%, respectively (P=0.08). This difference was primarily due to the need for target lesion revascularization in 4 patients (6%) in the coated-balloon group, compared with 10 patients (15%) in the stent group (P=0.15).
CONCLUSIONS: Treatment of coronary in-stent restenosis with the paclitaxel-coated balloon was at least as efficacious and as well tolerated as the paclitaxel-eluting stent. For the treatment of in-stent restenosis, inhibition of re-restenosis does not require a second stent implantation.
AD Institut für Klinische Forschung, Herz- und Kreislaufzentrum, Rotenburg, Germany.
AU Alfonso F, Pérez-Vizcayno MJ, Cárdenas A, García Del Blanco B, Seidelberger B, Iñiguez A, Gómez-Recio M, Masotti M, Velázquez MT, Sanchís J, García-Touchard A, Zueco J, Bethencourt A, Melgares R, Cequier A, Dominguez A, Mainar V, López-Mínguez JR, Moreu J, MartíV, Moreno R, Jiménez-Quevedo P, Gonzalo N, Fernández C, Macaya C
SO J Am Coll Cardiol. 2013 Dec;
OBJECTIVE: We sought to compare the efficacy of drug-eluting balloons (DEB) and everolimus-eluting stents (EES) in patients with bare-metal stent (BMS) in-stent restenosis (ISR).
BACKGROUND: Treatment of patients with ISR remains a challenge.
METHODS: This was a prospective, multicenter, randomized trial comparing DEB and EES in patients with BMS-ISR. The primary end-point was minimal lumen diameter at 9-month follow-up.
RESULTS: 189 patients with BMS-ISR from 25 Spanish sites were included (95 allocated to DEB and 94 to EES). Procedural success was achieved in all patients. At late angiography (median 249 days, 92% of eligible patients) patients in the EES arm had a significantly larger minimal lumen diameter (2.36+0.6 vs 2.01+0.6 mm, p<0.001; absolute mean difference 0.35 mm 95%CI 0.16-0.53) and a lower % diameter stenosis (13+17% vs 25+20%, p<0.001). However, late loss (0.04+0.5 vs 0.14+0.5 mm, p=0.14) and binary restenosis rate (4.7 vs 9.5%, p=0.22) were very low and similar in both groups. Clinical follow-up (median 365 days) was obtained in all (100%) patients. The occurrence of the combined clinical outcome measure (cardiac death, myocardial infarction and target vessel revascularization) (6 vs 8%; HR:0.76;95%CI:0.26-2.18, p=0.6) and the need for target vessel revascularization (2 vs 6%; HR:0.32:0.07-1.59, p=0.17) were similar in the 2 groups.
CONCLUSIONS: In patients with BMS-ISR both DEB and EES provide excellent clinical results with a very low rate of clinical and angiographic recurrences. However, as compared with DEB, EES provide superior late angiographic findings.
CLINICAL TRIAL INFO: NCT01239953.
AD Hospital Universitario de la Princesa, Madrid, Spain; Hospital Universitario Clínico San Carlos, Madrid, Spain. Electronic address: falf@hotmail.com.
AU Byrne RA, Neumann FJ, Mehilli J, Pinieck S, Wolff B, Tiroch K, Schulz S, Fusaro M, Ott I, Ibrahim T, Hausleiter J, Valina C, Pache J, Laugwitz KL, Massberg S, Kastrati A, ISAR-DESIRE 3 investigators
SO Lancet. 2013;381(9865):461.
BACKGROUND: The best way to manage restenosis in patients who have previously received a drug-eluting stent is unknown. We investigated the efficacy of paclitaxel-eluting balloons (PEB), paclitaxel-eluting stents (PES), and balloon angioplasty in these patients.
METHODS: In this randomised, open-label trial, we enrolled patients older than 18 years with restenosis of at least 50% after implantation of any limus-eluting stent at three centres in Germany between Aug 3, 2009, and Oct 27, 2011. Patients were randomly assigned (1:1:1; stratified according to centre) to receive PEB, PES, or balloon angioplasty alone by means of sealed, opaque envelopes containing a computer-generated sequence. Patients and investigators were not masked to treatment allocation, but events and angiograms were assessed by individuals who were masked. The primary endpoint was diameter stenosis at follow-up angiography at 6-8 months. Primary analysis was done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00987324.
FINDINGS: We enrolled 402 patients, of whom 137 (34%) were assigned to PEB, 131 (33%) to PES, and 134 (33%) to balloon angioplasty. Follow-up angiography at 6-8 months was available for 338 (84%) patients. PEB was non-inferior to PES in terms of diameter stenosis (38·0% [SD 21·5]vs 37·4% [21·8]; difference 0·6%, one-sided 95% CI 4·9%; p(non-inferiority)=0·007; non-inferiority margin of 7%). Findings were consistent in per-protocol analysis (p(non-inferiority)=0·011). PEB and PES were superior to balloon angioplasty alone (54·1% [25·0]; p(superiority)<0·0001 for both comparisons). Frequency of death, myocardial infarction, or target lesion thrombosis did not differ between groups.
INTERPRETATION: By obviating the need for additional stent implantation, PEB could be a useful treatment for patients with restenosis after implantation of a drug-eluting stent.
FUNDING: Deutsches Herzzentrum.
AD Deutsches Herzzentrum, Technische Universität, Munich, Germany. byrne@dhm.mhn.de
AU Gross CM, Krämer J, Weingärtner O, Uhlich F, Dietz R, Waigand J
SO Heart. 2000;84(3):307.
OBJECTIVE: To evaluate the clinical and angiographic outcome in patients with in-stent restenosis in small coronary arteries and repeat target lesion revascularisation.
DESIGN: Patients with in-stent restenosis in coronary arteries<or = 2.85 mm were eligible for the study and underwent target lesion revascularisation. Clinical and angiographic variables were assessed during a six month follow up period.
RESULTS: 73 patients with 79 lesions were treated by percutaneous transluminal coronary angioplasty (47%), excimer laser angioplasty (25%), or restenting (28%). The mean (SD) reference diameter before target lesion revascularisation was 2.12 (0.5) mm. Procedural success was achieved in all cases, but 57% of the patients had restenosis after six months. The rate of further restenosis was higher with laser angioplasty (78%) than with restenting (47%) or balloon angioplasty alone (49%, p<0.05).
CONCLUSIONS: Treatment for in-stent restenosis in small coronary arteries is feasible and safe, with a second restenosis rate comparable to large coronary artery series. The strategy of target lesion revascularisation influences further in-stent restenosis, with an increased rate with laser angioplasty compared with restenting and repeat dilatation alone.
AD Franz Volhard Clinic at the Max Delbrück Centre, Charité, Campus Berlin-Buch, Humboldt University, Berlin, Germany. Gross@fvk-berlin.de
AU Moustapha A, Assali AR, Sdringola S, Vaughn WK, Fish RD, Rosales O, Schroth G, Krajcer Z, Smalling RW, Anderson HV
SO J Am Coll Cardiol. 2001;37(7):1877.
OBJECTIVE: We examined long-term outcomes of patients with in-stent restenosis (ISR) who underwent different percutaneous interventions at the discretion of individual operators: balloon angioplasty (BA), repeat stent or rotational atherectomy (RA). We also examined long-term outcomes of patients with ISR who underwent coronary artery bypass surgery (CABG).
BACKGROUND: In-stent restenosis remains a challenging problem, and its optimal management is still unknown.
METHODS: Symptomatic patients (n = 510) with ISR were identified using cardiac catheterization laboratory data. Management for ISR included BA (169 patients), repeat stenting (117 patients), RA (107 patients) or CABG (117 patients). Clinical outcome events of interest included death, myocardial infarction, target vessel revascularization (TVR) and a combined end point of these major adverse cardiovascular events (MACE). Mean follow-up was 19+/-12 months (range = 6 to 61 months).
RESULTS: Patients with ISR treated with repeat stent had significantly larger average post-procedure minimal lumen diameter compared with BA or RA (3.3+/-0.4 mm vs. 3.0+/-0.4 vs. 2.9+/-0.5, respectively, p<0.05). Incidence of TVR and MACE were similar in the BA, stent and RA groups (39%, 40%, 33% for TVR and 43%, 40%, 33% for MACE, p = NS). Patients with diabetes who underwent RA had similar outcomes as patients without diabetes, while patients with diabetes who underwent BA or stent had worse outcomes than patients without diabetes. Patients who underwent CABG for ISR, mainly because of the presence of multivessel disease, had significantly better outcomes than any percutaneous treatment (8% for TVR and 23% for MACE).
CONCLUSIONS: In this large cohort of patients with ISR and in the subset of patients without diabetes, long-term outcomes were similar in the BA, repeat stent and RA groups. Tissue debulking with RA yielded better results only in diabetic patients. Bypass surgery for patients with multivessel disease and ISR provided the best outcomes.
AD University of Texas Medical School at Houston, USA.
AU Gaudino M, Cellini C, Pragliola C, Trani C, Burzotta F, Schiavoni G, Nasso G, Possati G
SO Circulation. 2005;112(9 Suppl):I265.
BACKGROUND: In patients who develop in-stent restenosis, successful revascularization can be difficult to achieve using percutaneous methods. This study was designed to verify the surgical results in this setting and to evaluate the potential beneficial role of arterial bypass conduits.
METHODS AND RESULTS: Sixty consecutive coronary artery bypass patients with previous in-stent restenosis and 60 control cases were randomly assigned to receive an arterial conduit (either right internal thoracic or radial artery; study group) or a great saphenous vein graft (control group) on the first obtuse marginal artery to complete the surgical revascularization procedure. At a mean follow-up of 52+/-11 months, patients were reassessed clinically and by angiography. Freedom from clinical and instrumental evidence of ischemia recurrence was found in 19 of 60 subjects in the study group versus 45 of 60 in the control series (P=0.01). The results of the arterial grafts were excellent in both the study and control groups (right internal thoracic artery patency rate, 19 of 20 for both, and radial artery patency rate, 20 of 20 versus 19 of 20; P=0.99). Saphenous vein grafts showed lower patency rate than arterial grafts in both series and had extremely high failure rate in the study group (patency rate, 10 of 20 in the study group versus 18 of 20 in the control group; P=0.001). Use of venous graft was an independent predictor of failure in the study group, whereas hypercholesterolemia was associated with graft failure in both series.
CONCLUSIONS: Venous grafts have an high incidence of failure among cases who previously developed in-stent restenosis, whereas the use of arterial conduits can improve the angiographic and clinical results. Arterial grafts should probably be the first surgical choice in this patient population.
AD Department of Cardiac Surgery, Catholic University, Rome, Italy. mgaudino@tiscali.it
AU Campo G, Tebaldi M, Vranckx P, Biscaglia S, Tumscitz C, Ferrari R, Valgimigli M
SO J Am Coll Cardiol. 2014;63(6):506.
Background It is still unclear if patients treated for ISR may benefit from a long DAPT regimen.
Methods For the present purpose, we selected 224 patients undergoing the PCI procedure for ISR enrolled in the PRODIGY (Prolonging Dual Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia) trial and randomized to short (6 months) versus long (24 months) DAPT regimen. The primary objective was the cumulative incidence of death, nonfatal myocardial infarction (MI), or cerebrovascular accident at 24 months. Safety endpoints were moderate and major bleeding complications.
Results Overall, 114 patients were allocated to short DAPT regimen, whereas 110 patients were allocated to long DAPT regimen. Twenty-seven patients reached the primary endpoint (19 in short DAPT regimen vs. 8 in long DAPT regimen; p = 0.02). The cumulative incidence of the primary endpoint at 24 months was 16.7% in the short DAPT regimen group compared with 7.3% in the long DAPT regimen group (p = 0.034). This is principally due to a lower occurrence of death and MI in the long DAPT regimen group as compared to the short DAPT regimen group (6.5% vs. 15.5%; p = 0.03). There was no difference in the occurrence of bleeding complications between long and short DAPT regimen.
Conclusions Our study offers preliminary evidence that patients receiving a new PCI procedure for ISR may benefit from long-term administration of aspirin plus clopidogrel. (Synergy Between Stent and Drugs to Avoid Ischemic Recurrences After Percutaneous Coronary Intervention
AU Wiviott SD1, Braunwald E, McCabe CH, Montalescot G, Ruzyllo W, Gottlieb S, Neumann FJ, Ardissino D, De Servi S, Murphy SA, Riesmeyer J, Weerakkody G, Gibson CM, Antman EM; TRITON-TIMI 38 Investigators.
SO N Engl J Med. 2007 Nov 15;357(20):2001-15. Epub 2007 Nov 4.
BACKGROUND:
Dual-antiplatelet therapy with aspirin and a thienopyridine is a cornerstone of treatment to prevent thrombotic complications of acute coronary syndromes and percutaneous coronary intervention.
METHODS:
To compare prasugrel, a new thienopyridine, with clopidogrel, we randomly assigned 13,608 patients with moderate-to-high-risk acute coronary syndromes with scheduled percutaneous coronary intervention to receive prasugrel (a 60-mg loading dose and a 10-mg daily maintenance dose) or clopidogrel (a 300-mg loading dose and a 75-mg daily maintenance dose), for 6 to 15 months. The primary efficacy end point was death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The key safety end point was major bleeding.
RESULTS:
The primary efficacy end point occurred in 12.1% of patients receiving clopidogrel and 9.9% of patients receiving prasugrel (hazard ratio for prasugrel vs. clopidogrel, 0.81; 95% confidence interval [CI], 0.73 to 0.90; P<0.001). We also found significant reductions in the prasugrel group in the rates of myocardial infarction (9.7% for clopidogrel vs. 7.4% for prasugrel; P<0.001), urgent target-vessel revascularization (3.7% vs. 2.5%; P<0.001), and stent thrombosis (2.4% vs. 1.1%; P<0.001). Major bleeding was observed in 2.4% of patients receiving prasugrel and in 1.8% of patients receiving clopidogrel (hazard ratio, 1.32; 95% CI, 1.03 to 1.68; P=0.03). Also greater in the prasugrel group was the rate of life-threatening bleeding (1.4% vs. 0.9%; P=0.01), including nonfatal bleeding (1.1% vs. 0.9%; hazard ratio, 1.25; P=0.23) and fatal bleeding (0.4% vs. 0.1%; P=0.002).
CONCLUSIONS:
In patients with acute coronary syndromes with scheduled percutaneous coronary intervention, prasugrel therapy was associated with significantly reduced rates of ischemic events, including stent thrombosis, but with an increased risk of major bleeding, including fatal bleeding. Overall mortality did not differ significantly between treatment groups. (ClinicalTrials.gov number, NCT00097591 [ClinicalTrials.gov].)
The lumen diameter reduction after percutaneous coronary intervention (PCI) is well known as “restenosis”. This phenomenon is due to vessel remodeling/recoil in case of no-stent strategy or, in case of stent employ, “neointimal proliferation” that consists in an excessive tissue proliferation in the luminal surface of the stent otherwise by a further new-occurring atherosclerotic process called “neoatherosclerosis”. The exact incidence of in-stent restenosis (ISR) is not easy to determine caused by different clinical, angiographic and operative factors. In the pre-stent era the occurrence of restenosis ranged between 32-55% of all angioplasties, and drop to successively 17-41% in the bare metal stents (BMS) era. The advent of drug eluting stent (DES), especially 2nd generation, and drug-coated balloon (DCB) further reduce restenosis rate until <10%. We here review the main characteristics of this common complication of coronary interventions, from its pathogenesis to the most appropriate treatment strategy.
UPDATED on 12/26/2020 – CABG: a Superior Revascularization Modality to PCI in Patients with poor LVF, Multivessel disease and Diabetes, Similar Risk of Stroke between 31 days and 5 years, post intervention
Reporter: Aviva Lev-Ari, PhD, RN
UPDATED on 4/28/2023
Statin loading before coronary artery bypass grafting: a randomized trial
Evidence suggests that a high-dose statin loading before a percutaneous coronary revascularization improves outcomes in patients receiving long-term statins. This study aimed to analyse the effects of such an additional statin therapy before surgical revascularization.
Additional statin loading before CABG failed to reduce the rate of MACCE occuring within 30 days of surgery.
Long-term outcomes after percutaneous coronary intervention (PCI) with contemporary drug-eluting stents, as compared with coronary-artery bypass grafting (CABG), in patients with left main coronary artery disease are not clearly established.
METHODS
We randomly assigned 1905 patients with left main coronary artery disease of low or intermediate anatomical complexity (according to assessment at the participating centers) to undergo either PCI with fluoropolymer-based cobalt–chromium everolimus-eluting stents (PCI group, 948 patients) or CABG (CABG group, 957 patients). The primary outcome was a composite of death, stroke, or myocardial infarction.
RESULTS
At 5 years, a primary outcome event had occurred in 22.0% of the patients in the PCI group and in 19.2% of the patients in the CABG group (difference, 2.8 percentage points; 95% confidence interval [CI], −0.9 to 6.5; P=0.13). Death from any cause occurred more frequently in the PCI group than in the CABG group (in 13.0% vs. 9.9%; difference, 3.1 percentage points; 95% CI, 0.2 to 6.1). In the PCI and CABG groups, the incidences of definite cardiovascular death (5.0% and 4.5%, respectively; difference, 0.5 percentage points; 95% CI, −1.4 to 2.5) and myocardial infarction (10.6% and 9.1%; difference, 1.4 percentage points; 95% CI, −1.3 to 4.2) were not significantly different. All cerebrovascular events were less frequent after PCI than after CABG (3.3% vs. 5.2%; difference, −1.9 percentage points; 95% CI, −3.8 to 0), although the incidence of stroke was not significantly different between the two groups (2.9% and 3.7%; difference, −0.8 percentage points; 95% CI, −2.4 to 0.9). Ischemia-driven revascularization was more frequent after PCI than after CABG (16.9% vs. 10.0%; difference, 6.9 percentage points; 95% CI, 3.7 to 10.0).
CONCLUSIONS
In patients with left main coronary artery disease of low or intermediate anatomical complexity, there was no significant difference between PCI and CABG with respect to the rate of the composite outcome of death, stroke, or myocardial infarction at 5 years. (Funded by Abbott Vascular; EXCEL ClinicalTrials.gov number, NCT01205776. opens in new tab.)
Is the Tide Turning on the ‘Grubby’ Affair of EXCEL and the European Guidelines?
Taggart was chair of the surgical committee for the Abbott-sponsored EXCEL trial, which compared two procedures for patients who had blockages in their left main coronary artery: percutaneous coronary intervention (PCI) using coronary stents, and coronary artery bypass graft surgery (CABG). The investigators designed the trial to compare outcomes for the two treatments using a composite endpoint of death, stroke, and myocardial infarction (MI). The 3-year follow-up data had been published in NEJM without controversy — or, at least, without public controversy.
But when it came time to publish the 5-year follow-up, there was a significantly higher rate of death in the stent group, and both Taggart and the journal editors were concerned that this finding was being downplayed in the manuscript.
In their comments to the authors, the journal editors had recommended including the mortality difference (unless clearly trivial) ‘”in the concluding statement in the final paragraph.” Yet, the concluding statement of the published paper read that there “was no significant difference between PCI and CABG.”
Over a year after the BBC received the leaked data, the EXCEL investigators published an analysis of the primary outcome using the universal definition of MI data in the Journal of the American College of Cardiology.
It shows 141 events in the PCI arm compared to 102 in the CABG arm. The investigators acknowledge that the rates of procedural MI differ depending on the definition used. According to their analysis, the protocol definition was predictive of mortality after both treatments, whereas the universal definition of procedural MI was predictive of mortality only after CABG. Not everyone agrees with this interpretation, and an accompanying editorial questioned these conclusions.
As for the guidelines, the tide may be turning.
In a joint statement with EACTS on October 6, 2020, the ESC agreed to review its guidelines for left main disease in the light of emerging, longer-term outcome data from the trials of CABG vs PCI.
SYNTAX at 10 Years: Bypass vs PCI Still a Toss-Up Overall
But CABG beats stenting for important subgroups
SYNTAX was funded by Boston Scientific.
Thuijs, Stone, and Taggart disclosed no conflicts.
Baumbach reported receiving institutional research support from Abbott Vascular; and consultation and speaker fees from AstraZeneca, Sinomed, Microport, Abbott Vascular, Cardinal Health, KSH, Medtronic.
Pagano is the Secretary General of the European Association for Cardiothoracic Surgery.
LAST UPDATED
Overall, mortality curves did not diverge over time for SYNTAX participants now included in the trial’s extension study SYNTAXES: by 1o years, all-cause death reached 27.0% among those randomized to percutaneous coronary intervention (PCI) and 23.5% of the CABG arm (HR 1.17, 95% CI 0.97-1.41), according to Daniel Thuijs, MD, of Erasmus University Medical Centre in Rotterdam, the Netherlands.
However, people with three-vessel disease had particularly high mortality when assigned to PCI in lieu of CABG (27.7% vs 20.6%, HR 1.41, 95% CI 1.10-1.80), whereas peers with left main disease were no worse off after either procedure (26.1% vs 26.7%, HR 0.90, 95% CI 0.68-1.52),Thuijs told the audience during a late-breaking trial session at the European Society of Cardiology’s annual congress. The study was also published online in The Lancet.
CABG had a mortality benefit over PCI in patients with multivessel disease, particularly those with diabetes and higher coronary complexity. No benefit for CABG over PCI was seen in patients with left main disease. Longer follow-up is needed to better define mortality differences between the revascularisation strategies.
JACC Study, 7/2018
CONCLUSIONS
This individual patient-data pooled analysis demonstrates that 5-year stroke rates are significantly lower after PCI compared with CABG, driven by a reduced risk of stroke in the 30-day post-procedural period but a similar risk of stroke between 31 days and 5 years. The greater risk of stroke after CABG compared with PCI was confined to patients with multivessel disease and diabetes. Five-year mortality was markedly higher for patients experiencing a stroke within 30 days after revascularization.
European Journal of Cardiothoracic Surgery Study, 6/2018
CONCLUSIONS
Despite a longer length of hospital stay, patients with impaired LVF requiring intervention for coronary artery disease experienced a greater post-procedural survival benefit if they received CABG compared to PCI. We have demonstrated this at 30 days, 90 days, 1 year, 3 years, 5 years and 8 years following revascularization. At present, CABG remains a superior revascularization modality to PCI in patients with poor LVF.
New Studies on Clinical Outcomes from two Revascularization Strategies: CABG and PCI
J Am Coll Cardiol. 2018 Jul 24;72(4):386-398. doi: 10.1016/j.jacc.2018.04.071.
Stroke Rates Following Surgical Versus Percutaneous Coronary Revascularization.
Coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are used for coronary revascularization in patients with multivessel and left main coronary artery disease. Stroke is among the most feared complications of revascularization. Due to its infrequency, studies with large numbers of patients are required to detect differences in stroke rates between CABG and PCI.
OBJECTIVES:
This study sought to compare rates of stroke after CABG and PCI and the impact of procedural stroke on long-term mortality.
METHODS:
We performed a collaborative individual patient-data pooled analysis of 11 randomized clinical trials comparing CABG with PCI using stents; ERACI II (Argentine Randomized Study: Coronary Angioplasty With Stenting Versus Coronary Bypass Surgery in Patients With Multiple Vessel Disease) (n = 450), ARTS (Arterial Revascularization Therapy Study) (n = 1,205), MASS II (Medicine, Angioplasty, or Surgery Study) (n = 408), SoS (Stent or Surgery) trial (n = 988), SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) trial (n = 1,800), PRECOMBAT (Bypass Surgery Versus Angioplasty Using Sirolimus-Eluting Stent in Patients With Left Main Coronary Artery Disease) trial (n = 600), FREEDOM (Comparison of Two Treatments for Multivessel Coronary Artery Disease in Individuals With Diabetes) trial (n = 1,900), VA CARDS (Coronary Artery Revascularization in Diabetes) (n = 198), BEST (Bypass Surgery Versus Everolimus-Eluting Stent Implantation for Multivessel Coronary Artery Disease) (n = 880), NOBLE (Percutaneous Coronary Angioplasty Versus Coronary Artery Bypass Grafting in Treatment of Unprotected Left Main Stenosis) trial (n = 1,184), and EXCEL (Evaluation of Xience Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial (n = 1,905). The 30-day and 5-year stroke rates were compared between CABG and PCI using a random effects Cox proportional hazards model, stratified by trial. The impact of stroke on 5-year mortality was explored.
RESULTS:
The analysis included 11,518 patients randomly assigned to PCI (n = 5,753) or CABG (n = 5,765) with a mean follow-up of 3.8 ± 1.4 years during which a total of 293 strokes occurred. At 30 days, the rate of stroke was 0.4% after PCI and 1.1% after CABG (hazard ratio [HR]: 0.33; 95% confidence interval [CI]: 0.20 to 0.53; p < 0.001). At 5-year follow-up, stroke remained significantly lower after PCI than after CABG (2.6% vs. 3.2%; HR: 0.77; 95% CI: 0.61 to 0.97; p = 0.027). Rates of stroke between 31 days and 5 years were comparable: 2.2% after PCI versus 2.1% after CABG (HR: 1.05; 95% CI: 0.80 to 1.38; p = 0.72). No significant interactions between treatment and baseline clinical or angiographic variables for the 5-year rate of stroke were present, except for diabetic patients (PCI: 2.6% vs. CABG: 4.9%) and nondiabetic patients (PCI: 2.6% vs. CABG: 2.4%) (p for interaction = 0.004). Patients who experienced a stroke within 30 days of the procedure had significantly higher 5-year mortality versus those without a stroke, both after PCI (45.7% vs. 11.1%, p < 0.001) and CABG (41.5% vs. 8.9%, p < 0.001).
CONCLUSIONS:
This individual patient-data pooled analysis demonstrates that 5-year stroke rates are significantly lower after PCI compared with CABG, driven by a reduced risk of stroke in the 30-day post-procedural period but a similar risk of stroke between 31 days and 5 years. The greater risk of stroke after CABG compared with PCI was confined to patients with multivessel disease and diabetes. Five-year mortality was markedly higher for patients experiencing a stroke within 30 days after revascularization.
Head SJ, Milojevic M, Daemen J, Ahn JM, Boersma E, Christiansen EH, Domanski MJ, Farkouh ME, Flather M, Fuster V, Hlatky MA, Holm NR, Hueb WA, Kamalesh M, Kim YH, Mäkikallio T, Mohr FW, Papageorgiou G, Park SJ, Rodriguez AE, Sabik JF, Stables RH, Stone GW, Serruys PW, Kappetein AP. Mortality after coronary artery bypass grafting versus percutaneous coronary intervention with stenting for coronary artery disease: a pooled analysis of individual patient data. Lancet. 2018 Feb 22 [Epub ahead of print]. doi: 10.1016/S0140-6736(18)30423-9. PMID: 29478841
Numerous randomised trials have compared coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) for patients with coronary artery disease. However, no studies have been powered to detect a difference in mortality between the revascularisation strategies.
Methods
We did a systematic review up to July 19, 2017, to identify randomised clinical trials comparing CABG with PCI using stents. Eligible studies included patients with multivessel or left main coronary artery disease who did not present with acute myocardial infarction, did PCI with stents (bare-metal or drug-eluting), and had more than 1 year of follow-up for all-cause mortality. In a collaborative, pooled analysis of individual patient data from the identified trials, we estimated all-cause mortality up to 5 years using Kaplan-Meier analyses and compared PCI with CABG using a random-effects Cox proportional-hazards model stratified by trial. Consistency of treatment effect was explored in subgroup analyses, with subgroups defined according to baseline clinical and anatomical characteristics.
Findings
We included 11 randomised trials involving 11 518 patients selected by heart teams who were assigned to PCI (n=5753) or to CABG (n=5765). 976 patients died over a mean follow-up of 3·8 years (SD 1·4). Mean Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score was 26·0 (SD 9·5), with 1798 (22·1%) of 8138 patients having a SYNTAX score of 33 or higher. 5 year all-cause mortality was 11·2% after PCI and 9·2% after CABG (hazard ratio [HR] 1·20, 95% CI 1·06–1·37; p=0·0038). 5 year all-cause mortality was significantly different between the interventions in patients with multivessel disease (11·5% after PCI vs 8·9% after CABG; HR 1·28, 95% CI 1·09–1·49; p=0·0019), including in those with diabetes (15·5% vs 10·0%; 1·48, 1·19–1·84; p=0·0004), but not in those without diabetes (8·7% vs 8·0%; 1·08, 0·86–1·36; p=0·49). SYNTAX score had a significant effect on the difference between the interventions in multivessel disease. 5 year all-cause mortality was similar between the interventions in patients with left main disease (10·7% after PCI vs 10·5% after CABG; 1·07, 0·87–1·33; p=0·52), regardless of diabetes status and SYNTAX score.
Interpretation
CABG had a mortality benefit over PCI in patients with multivessel disease, particularly those with diabetes and higher coronary complexity. No benefit for CABG over PCI was seen in patients with left main disease. Longer follow-up is needed to better define mortality differences between the revascularisation strategies.
Comparison of the survival between coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with poor left ventricular function (ejection fraction <30%): a propensity-matched analysis.
Existing evidence comparing the outcomes of coronary artery bypass graft (CABG) surgery versus percutaneous coronary intervention (PCI) in patients with poor left ventricular function (LVF) is sparse and flawed. This is largely due to patients with poor LVF being underrepresented in major research trials and the outdated nature of some studies that do not consider drug-eluting stent PCI.
METHODS:
Following strict inclusion criteria, 717 patients who underwent revascularization by CABG or PCI between 2002 and 2015 were enrolled. All patients had poor LVF (defined by ejection fraction <30%). By employing a propensity score analysis, 134 suitable matches (67 CABG and 67 PCI) were identified. Several outcomes were evaluated, in the matched population, using data extracted from national registry databases.
RESULTS:
CABG patients required a longer length of hospital stay post-revascularization compared to PCI in the propensity-matched population, 7 days (lower-upper quartile; 6-12) and 2 days (lower-upper quartile; 1-6), respectively (Mood’s median test, P = 0.001). Stratified Cox-regression proportional-hazards analysis of the propensity-matched population found that PCI patients experienced a higher adjusted 8-year mortality rate (hazard ratio 3.291, 95% confidence interval 1.776-6.101; P < 0.001). This trend was consistent amongst urgent cases of revascularization: patients with 3 or more vessels with coronary artery disease and patients where complete revascularization was achieved. Although sub-analyses found no difference between survival distributions of on-pump versus off-pump CABG (log-rank P = 0.726), both modes of CABG were superior to PCI (stratified log-rank P = 0.002).
CONCLUSIONS:
Despite a longer length of hospital stay, patients with impaired LVF requiring intervention for coronary artery disease experienced a greater post-procedural survival benefit if they received CABG compared to PCI. We have demonstrated this at 30 days, 90 days, 1 year, 3 years, 5 years and 8 years following revascularization. At present, CABG remains a superior revascularization modality to PCI in patients with poor LVF.
What is the Role of Noninvasive Diagnostic Fractional Flow Reserve (FFR) CT vs Invasive FFR for PCI?
Reporter: Aviva Lev-Ari, PhD, RN
UPDATED on 7/31/2019
During the AHRA presentation, Ali Westervelt cited a study published in the Journal of the American College of Cardiology indicating that questions about obstructive coronary artery disease (CAD) in six of 10 patients who might otherwise be sent for cardiac catheterization could be answered with FFRct. During the presentation, Westervelt described a slide indicating that FFR-CT can dramatically reduce the need for cardiac catheterization. Its use, she said, focuses attention on patients most likely to test positively for CAD, as three of four patients sent to cardiac cath are found to have coronary artery disease.
The slide was based on research presented in the paper “1-Year Outcomes of FFRCT-Guided Care in Patients With Suspected Coronary Disease.” Westervelt and her colleague in the presentation, Curt Bush, noted that at one-year follow-up, no cardiac events were seen in 117 patients who had cardiac cath cancelled based on FFR-CT results. Additionally, mean costs were 33 percent lower with FFRct versus the usual care strategy — $8,127 compared with $12,145, respectively. The authors of the paper concluded that “selective FFR-CT was associated with equivalent clinical outcomes, quality of life, and lower costs, compared with usual care over one-year follow-up.”
FFR-CT has been proven to reduce unnecessary hospital admissions, according to Bush and Westervelt. In their presentation, they cited research showing that FFRct provides the information that cardiologists need without the expense, time or patient inconvenience of tests done in the nuclear medicine or cardiac catheterization labs.
Despite the advantages of FFR-CT, however, only about 200 facilities in the United States perform this procedure, according to Westervelt, who speculated that the young age of the procedure and its reimbursement status may have been barriers to wider adoption. “It is only about a three-year-old technology and until recently was not reimbursable,” she said.
The Centers for Medicare and Medicaid Services (CMS) began paying for FFR-CT January 2018. “I think there was just not a lot of interest because everybody is looking at their business plan,” said Westervelt, who is transitioning to a new job in which she expects to perform FFR-CT.
An interview with Patrick Serruys, M.D., Ph.D., Imperial College London, principal investigator of the SYNTAX III Trial presented earlier this year as a late-breaker at EuroPCR. He presented the trial again at the Society of Cardiovascular Computed Tomography (SCCT) 2018 meeting.
What is the Role of Noninvasive Diagnostic Fractional Flow Reserve (FFR) CT vs Invasive FFR for PCI?
02/27/2018
We know that FFRCT, the method of obtaining FFR from computed tomography angiographic (CTA) images, has been approved by Medicare and other third-party payers. It is used before patients come to the cath lab. The use of FFRCT in the PLATFORM study1reduced the number of unnecessary cardiac caths that had normal coronary angiography, while maintaining the same number of patients needing PCI. Before discussing the role of angio-derived FFR, let’s review how FFRCT is obtained (Figure 1). Starting with any good quality CTA, the images are sent, offline, to HeartFlow Inc.2 To derive the FFR, the CTA images are reconstructed into a 3-dimensional coronary tree, segmenting it into individual points with each point undergoing processing by specialized equations (i.e., Navier-Stokes equations) to compute pressure loss along the course of the artery at rest and again during an assumed hyperemic state. These computational fluid dynamic equations require several assumptions from a population model regarding the myocardial blood flow rates as a function of the myocardial arterial branches and the resistance of the myocardium. These values are put into the computational flow dynamics (CFD) model, and using high-power computers, the FFR is generated along the entire course of each vessel. FFRCT has been validated against invasive FFR and found to be about 80% correlative in several studies.3,4 FFRCT has better correlation with FFR than most stress tests, and based on clinical outcome data, will likely replace traditional stress testing, with a reduction in procedures in patients without significant coronary disease. However, there are some operators who may be confused, thinking that FFRCT will replace invasive FFR. FFRCT screens for important coronary artery disease (CAD) before the patient comes to the cath lab, and then once in the lab, the operators can confirm lesion significance with FFR.
Noninvasive FFR Derived From Angiography: Wireless FFR in the Lab?
Wouldn’t it be great to get the FFR from the angiogram without having to put in a guidewire? This is in our near future. The generation of a “virtual” FFR derived from angiography or other modalities (Table 1A-B, Figures 2-4) has been proposed using computational flow dynamics (CFD) or rapid flow analysis to obtain wireless image-based FFR, incorporated into the diagnostic angiography workflow. As one might expect, online implementation of angio-derived FFR requires novel concepts and systems to reduce computation time and make the analysis process acceptable to in-lab functions. Early data shows that angio-derived FFR can be obtained within several minutes during a regular coronary angiogram.5
Angio-FFR Validation StudiesTwo contenders for introduction to the cath labs in the near future are QFR and FFRangio. QFR (Quantitative Flow Ratio, Medis Medical Imaging Systems) validation was reported in the FAVOR II China study, which reported the vessel-level diagnostic accuracy of QFR in identifying hemodynamically-significant coronary stenosis was 97.7% and patient-level diagnostic accuracy was 92.4% (P<0.001 for both).6 In addition, the FAVOR II Europe-Japan trial demonstrated that QFR had superior sensitivity and specificity in comparison to 2-D QCA with FFR as the gold standard: 88% vs 46% and 88% vs 77% (P<0.001 for both). The overall diagnostic accuracy of QFR was 88%.7 For FFRangio (CathWorks), the sensitivity, specificity, and diagnostic accuracy of FFRangio were 88%, 95%, and 93%, respectively.5 The strong concordance with invasive, wire-based FFR will likely make these methods widely available, but of course, early favorable results require confirmation. Once confirmed in larger studies and for a wider spectrum of coronary lesions, angio-derived FFR should become a routine part of diagnostic angiography.
Accuracy in computing noninvasive FFR is based on the implementation of complex computational methods that can differ among the various competing methods. In contrast to FFRCT, which creates a complete and detailed 3D model of the coronary tree from CTA scans, Tu et al8 constructed vessel geometry from routine angiography, applying a simpler model for flow, derived from the division of coronary branches (as opposed to using an estimate of flow from myocardial mass)2, and an approximate algebraic computational method from experimental studies of flow through single arterial stenosis models8 (as opposed to CFD equations) to solve for pressure drop and FFR (Figure 5). Because Tu et al8 do not employ the complicated Navier-Stokes equations, the computational time is almost instantaneous once the geometry is segmented into “sub segments” from the 3D rendering. Pellicano et al5 constructed 3D artery geometry from routing angiography alone, applying rapid flow analysis where all stenoses are converted into resistances in a lumped model, while scaling laws (of branches) are used to estimate the microcirculatory bed resistance.
Competition for a winning method of angiographically-derived FFR is underway, with different companies using different models and different assumptions regarding flow and resistance inputs (Table 1A-B). An example is QFR that uses several assumptions related to flow variables. fQFR is specified hyperemic inflow, assuming a fixed inflow velocity of 0.35 m/s. cQFR is “virtual” hyperemic flow, determined from a model based on TIMI [Thrombolysis In Myocardial Infarction] frame count, relating measured flow under baseline conditions to hyperemic flow. Lastly, aQFR is the variable of directly measured hyperemic flow. From these assumptions, QFR gives highly comparable results to invasive FFR.
Advantages of Angio-Derived FFR
The in-lab computations of angio-derived FFR are fast and have the potential to provide wireless FFR lesion assessment to every angiographic procedure. Other advantages of angio-derived FFR are obvious. There is no need to insert a pressure guidewire. Pharmacologic hyperemia is not necessary. It is nearly operator independent. The angio-derived FFR is also co-registered on the angiogram with accurate and reproducible results. In addition, 3D reconstruction of the coronary tree can enhance the identification of reference vessel diameters for selection of stent sizing, and ultimately predict anatomic and physiological outcomes.5
Limitations of Angio-Derived FFR
The image acquisition requirements and the user interface of an image-based FFR system should be seamlessly incorporated into the standard work of the catheterization laboratory. Data acquisition should minimally disrupt routine angiography. Angio-derived FFR should only require the acquisition of 2 to 3 conventional radiographic projections in which the lesions can be clearly seen. It is important to visualize the entire coronary tree on the screen and to optimize vessel opacification. Poor images or overlapped segments will limit the accuracy of angio-derived FFR. The image acquisition angles needed for angio-derived FFR are the same as those used for routine procedures. High resolution imaging at >10 frames/sec are needed.5
On the technical side, coronary microvascular resistance (CMV) is a fundamental assumption to compute pressure from flow. CMV in one study was derived from invasive measurements, something which will limit future acceptance.9 As the data sets are accumulated, it is hoped that invasive CMV will not be needed. One angio-derived FFR method, vFFR9,10, requires rotational angiography, which is not yet widely available, and may produce asymmetric coronary segmentations — a concern for accurate analysis.
Finally, the amount of time required to acquire and process the data to produce angio-derived FFR is likely to be longer than the 3-minute computation time. Acquisition time should realistically include the time to overcome the difficulties of imaging complex anatomy, eliminate artifacts, upload the study for CFD analysis, and create the volumetric mesh. Furthermore, there will probably be patient-specific errors related to abnormal coronary physiology which may account for outliers in the correlations between angiography-derived and invasive FFR measurements.11
Angio-derived FFR is currently reported for off-line results, but, recently, online applications have also been presented. Minimal operator interaction is necessary in the flow calculation process, which results in low inter-operator variability.
The Bottom Line
When FFRCT and angio-derived FFR technology ultimately become more widely available, they will radically change the way diagnostic angiography is performed in the same way that invasive FFR changed the way we approach patients needing PCI.
References
Douglas PS, De Bruyne B, Pontone G, et al. 1-Year Outcomes of FFRCT-Guided Care in Patients With Suspected Coronary Disease: The PLATFORM Study. J Am Coll Cardiol. 2016 Aug 2; 68(5): 435-445. doi: 10.1016/j.jacc.2016.05.057.
Taylor CA, Fonte TA, Min JK. Computational fluid dynamics applied to cardiac computed tomography for noninvasive quantification of fractional flow reserve: scientific basis. J Am Coll Cardiol. 2013; 61(22): 2233-2241.
Norgaard BL, Leipsic J, Gaur S, et al. Diagnostic performance of noninvasive fractional flow reserve derived from coronary computed tomography angiography in suspected coronary artery disease. J Am Coll Cardiol. 2014; 63: 1145-1155.
Min JK, Leipsic J, Pencina MJ, et al. Diagnostic accuracy of fractional flow reserve from anatomic CT angiography. JAMA. 2012; 308: 1237-1234.
Pellicano M, Lavi I, Bruyne B, et al. Validation study of image-based fractional flow reserve during coronary angiography. Circ Cardiovasc Interv. 2017; 10: e005259. doi: 10.1161/CIRCINTERVENTIONS.116.005259.
Xu B, Tu S, Qiao S, et al. Diagnostic accuracy of angiography-based quantitative flow ratio measurements for online assessment of coronary stenosis. J Am Coll Cardiol. 2017 Dec 26; 70(25): 3077-3087. doi: 10.1016/j.jacc.2017.10.035.
Tu S, Westra J, Yang J, et al. Diagnostic accuracy of fast computational approaches to derive fractional flow reserve from diagnostic coronary angiography: the international multicenter FAVOR pilot study. J Am Coll Cardiol Intv. 2016; 9: 2024-2035.
Morris PD, van de Vosse FN, Lawford PV, et al. “Virtual” (computed) fractional flow reserve: current challenges and limitations. JACC Cardiovasc Interv. 2015; 8: 1009-1017. doi: 10.1016/j.jcin.2015.04.006.
Morris PD, Ryan D, Morton AC, et al. Virtual fractional flow reserve from coronary angiography: modeling the significance of coronary lesions: results from the VIRTU-1 (VIRTUal Fractional Flow Reserve From Coronary Angiography) study. JACC Cardiovasc Interv. 2013; 6: 149-157. doi: 10.1016/j.jcin.2012.08.024.
Papafaklis MI, Muramatsu T, Ishibashi Y, et al. Fast virtual functional assessment of intermediate coronary lesions using routine angiographic data and blood flow simulation in humans: comparison with pressure wire – fractional flow reserve. EuroIntervention. 2014; 10: 574-583. doi: 10.4244/EIJY14M07_01
Tu S, Barbato E, Köszegi Z, et al. Fractional flow reserve calculation from 3-dimensional quantitative coronary angiography and TIMI frame count: a fast computer model to quantify the functional significance of moderately obstructed coronary arteries. JACC Cardiovasc Interv. 2014 Jul; 7(7): 768-777. doi: 10.1016/j.jcin.2014.03.004.
Disclosure: Dr. Kern is a consultant for Abiomed, Merit Medical, Abbott Vascular, Philips Volcano, ACIST Medical, Opsens Inc., and Heartflow Inc.
Expanded Stroke Thrombectomy Guidelines: FDA expands treatment window for use (Up to 24 Hours Post-Stroke) of clot retrieval devices (Stryker’s Trevo Stent) in certain stroke patients
Reporter: Aviva Lev-Ari, PhD, RN
The stent retriever from Stryker was cleared for thrombectomy-eligible patients as initial therapy to reduce paralysis and other stroke disability only as an addition to tissue plasminogen activator (tPA). Previously, the device was approved only for use within 6 hours of ischemic stroke onset.
FDA Clears Trevo Stent Retriever for Up to 24 Hours Post-Stroke
FDA move follows expanded stroke thrombectomy guidelines
by Nicole Lou, Reporter, MedPage Today/CRTonline.org
“Time is critical following the onset of stroke symptoms. Expanding the treatment window from 6 to 24 hours will significantly increase the number of stroke patients who may benefit from treatment,” said Carlos Peña, PhD, director of the division of neurological and physical medicine devices at the FDA’s Center for Devices and Radiological Health, in a statement. “Healthcare providers and their patients now have better tools for treating stroke and potentially preventing long-term disability.”
The American Heart Association and American Stroke Association recently revised their guidelines to recommend stent retriever use up to 24 hours after symptom onset. This was announced at the International Stroke Conference in January, where the DEFUSE 3 trial added to the evidence from DAWN in demonstrating benefits to relatively late endovascular thrombectomy.
In particular, DAWN data were used to support the FDA’s latest decision. Trial investigators had reported more functional independence when patients were randomized to Trevo thrombectomy over medical management alone.
FDA expands treatment window for use of clot retrieval devices in certain stroke patients
For Immediate Release
February 15, 2018
Summary
FDA expands treatment window for use of clot retrieval devices in certain stroke patients
Release
The U.S. Food and Drug Administration today cleared the use of the Trevo clot retrieval device to treat certain stroke patients up to 24 hours after symptom onset, expanding the device’s indication to a broader group of patients. This device is cleared for use as an initial therapy for strokes due to blood clots (also known as an acute ischemic stroke) to reduce paralysis, speech difficulties and other stroke disabilities and only as an addition to treatment with a medication that dissolves blood blots called tissue plasminogen activator (t-PA). The device was previously cleared for use in patients six hours after symptom onset.
“Time is critical following the onset of stroke symptoms. Expanding the treatment window from 6 to 24 hours will significantly increase the number of stroke patients who may benefit from treatment,” said Carlos Peña, Ph.D., director of the division of neurological and physical medicine devices at the FDA’s Center for Devices and Radiological Health. “Health care providers and their patients now have better tools for treating stroke and potentially preventing long-term disability.”
A stroke is a serious medical condition that requires emergency care and can cause lasting brain damage, long-term disability or even death. According to the Centers for Disease Control and Prevention, stroke is the fifth leading cause of death in the U.S. and is a major cause of serious disability for adults. About 795,000 people in the U.S. have a stroke each year. Ischemic strokes represent about 87 percent of all strokes.
The Trevo device was first cleared by the FDA in 2012 to remove a blood clot and restore blood flow in stroke patients who could not receive t-PA or for those patients who did not respond to t-PA therapy. In 2016, the FDA allowed expanded marketing of the device for certain patients in addition to treatment with t-PA if used within six hours of the onset of symptoms. Today’s expanded indication increases the amount of time that the device can be used once the symptoms are present.
Trevo is a clot removal device that is inserted through a catheter up into the blood vessel to the site of the blood clot. When the shaped section at the end of the device is fully expanded (up to three to six millimeters in diameter), it grips the clot, allowing the physician to retrieve the clot by pulling it back through the blood vessel along with the device for removal through a catheter or sheath.
The FDA evaluated data from a clinical trial comparing 107 patients treated with the Trevo device and medical management to 99 patients who had only medical management. About 48 percent of patients treated with the Trevo device were functionally independent (ranging from no symptoms to slight disability) three months after their stroke compared to 13 percent of patients who were not treated with the Trevo device.
Risks associated with using the Trevo device include a failure to retrieve the blood clot, embolization (blockage) to new territories in the brain, arterial dissections and vascular perforations, and access site complications at the femoral (thigh) artery entry point.
Trevo was reviewed through the premarket notification (510(k)) pathway. A 510(k) is a premarket submission made by device manufacturers to the FDA to demonstrate that the new device is substantially equivalent to a legally marketed predicate device. The FDA granted premarket clearance of the Trevo device to Concentric Medical Inc.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.
Spectranetics, a Technology Leader in Medical Devices for Coronary Intervention, Peripheral Intervention, Lead Management to be acquired by Philips for 1.9 Billion Euros
Dutch healthcare company Philips (PHG.AS) has agreed to buy U.S.-based Spectranetics Corp (SPNC.O), a maker of devices to treat heart disease, for 1.9 billion euros (£1.68 billion) including debt, as it expands its image-guided therapy business.
Spectranetics uses techniques including lasers and tiny drug-covered balloons to clean the insides of veins and arteries that have become clogged due to heart disease.
Philips will pay Spectranetics shareholders $38.50 per share, a 27 percent premium to their closing price on June 27.
Philips Chief Executive Frans van Houten has transformed the former conglomerate into a focused maker of healthcare equipment over the past five years, spinning off its lighting division (LIGHT.AS) and selling most of its remaining consumer products business.
Philips said Spectranetics, which expects sales of around $300 million this year, will continue to grow revenues at double-digit rates and will begin adding to Philips’ earnings in 2018.
Coronary Artery Disease (CAD) is the leading cause of death among men and women. Each year, one in four deaths are attributed to CAD in the United States, accounting for over a half million lives lost. From scoring balloon technology to laser atherectomy to thrombus aspiration and removal, Spectranetics offers a comprehensive portfolio of solutions to cross, prep and treat compromised vessels. Learn more about CAD by navigating through the tile grid below and exploring the products that are saving lives.
Spectranetics is dedicated to helping physicians cross, prep and treat complex clinical challenges of Peripheral Artery Disease, such as Critical Limb Ischemia, Chronic Total Occlusions and In-Stent Restenosis. We provide expert tools, training, ongoing support and patient education so that you can help eradicate restenosis, and amputation and modify all plaque. Explore the tile grid below to learn more about Peripheral Artery Disease and Spectranetics’ comprehensive portfolio of products to successfully treat this challenging cardiovascular condition at every stage.
Managing cardiac implantable electronic device (CIED) leads has never been more important. Patients with CIEDs are on a lifelong journey, and Spectranetics is there to make sure it’s a healthy one. Making the right decision at the right time, for every patient, is critical. Lives depend on it. Explore the tile grid below to learn more about Lead Management and the products that ensure lead extraction is done safely, responsibly and predictably.
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FFR-CT has been proven to reduce unnecessary hospital admissions, according to Bush and Westervelt. In their presentation, they cited research showing that FFRct provides the information that cardiologists need without the expense, time or patient inconvenience of tests done in the nuclear medicine or cardiac catheterization labs.
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