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Posts Tagged ‘Coronary circulation’


Introducing Dr. Tim Wu – Interventional Cardiologist, Inventor and Entrepreneur

Author: Ed Kislauskis, PhD

Welcome readers to the first in a series of interviews with future scientific leaders in biotechnology and medicine.  In this post I interview a close colleague and clinical scientist who appears to be on a fast-track to achieving his vision for the future of interventional cardiology – at the very vanguard of applied nanotechnology.

Tim (Tiangen) Wu, M.D has graciously accepted my invitation to answer a few questions about how his career path and primary goal to develop and commercialize his first product, a fully-biodegradable drug-eluting stent he calls the PowerStent® Absorb (see insert).  This technology combines three especially innovations:  a unique balloon-expandable stent design (PowerStent®), a bioabsorbable nanoparticle composition (BioDe®), and a formulation of two commercially-available anti-restenosis drugs (Combo®).

Stent

About the Subject

Dr. Wu received his clinical education in China and research training in the USA. In 1988, he graduated with an MD from the prestigious Linyli Medical School and completed a fellowship in clinical cardiology at the Tonji Medical University.  In 1993, presented with an opportunity to travel to the US, he uprooted to accept a position as visiting scholar, and ultimately post-doctoral fellow,in Jeffrey Isner’s lab at St. Elizabeth Hospital (Tufts University) and the Beth Israel Medical Center (Harvard Medical).  There he investigated the biology of stenosis, and directed sponsored research projects to evaluate the safety and efficacy of the latest commercially-developed drug-coated stents (DES) in animals.

After  a decade in academia, Dr. Wu made the successful transition to industry and joined Nitromed Inc. as a Research Scientist.  His next stop was as a Research Director at Biomedical Research Models, Inc (2000-2006) where we met and collaborated on developing and characterizing macrovascular disease in an inbred, type 2 diabetic rat model.  After a 20 year career, and upon gaining additional qualification in Mechanical Engineering (Wentworth Institute), Business Administration (MIT), Clinical Research Affairs (Mass. Biotech Council), and Medical Device Regulatory Affairs (North Eastern Univ.), he was ready to take the entrepreneurial leap.  His first company, VasoTech would aim to re-engineer the clinical standards of stent design and drug delivery.

In 2007, Dr. Wu founded VasoTech, Inc. from inside his home garage. Less than a year later, VasoTech received a $1.5M SBIR fast-track grant award from the NIH.  With funding, VasoTech joined the newly announced M2D2 facility on the University of Massachusetts Lowell campus, and expanded operations in China.  With the support of one of his closest advisors, Dr. Stephen McCarthy and other research faculty, Dr. Wu was appointed as an adjunct faculty in the Dept. of BioMedical Engineering at the UMass/Lowell where he mentored a number of talented graduate students.  Dr. Wu is recognized as a senior reviewer on the NIH Bioengineering, Surgical Science and Technology Study Section, and Biomaterials, Delivery Systems and Nanotechnology Special Emphasis Panels servicing the  Small Business Innovation Research (SBIR) grant program.

Dr. Wu’s work at Vasotech is devoted to developing a 3rd generation of fully biodegradable DES coronary stents to solve two major complications associated with stenting, restenosis and late-stage thrombosis. Thusfar, his ideas have attracted well over $1.5 Million (USD) in Small Business Innovation Research (SBIR) grant awards from the National Institute of Diabetes and Digestive and Kidney Diseases, and $1million (USD) from China Innovative Talent Leadership Program.  Through his efforts VasoTech is well positioned to attract the strategic partnerships and venture capital investments necessary to translate his research through clinical stages of development both in China and the US.

The Interview

Kislauskis:  Please help our readers understand the current clinical approach to CAD.

Wu:  Most patients with advanced atherosclerosis diseases are at risk for occlusive coronary arterial disease and stroke. Consequently, it is recommended they undergo a percutaneous intervention (PCI); essentially, balloon angioplasty followed by instillation of one or more expandable metal stents. A properly expanded stent will dilate the vessel and increase blood flow to cardiac muscle tissue. Current 2nd generation drug-eluting-stents (DES) release drugs to inhibit the process of vascular remodeling leading to restenosis. Because the DES approach is remarkably successful and lowers the rate of restenosis to < 10%, DESs is now performed in 85% of the 2 million percutaneous coronary interventions (PCI) procedures annually in the U.S.

Kislauskis:  What is your impression of the recent 5 yr update of the FREEDOM trial comparing effectiveness of coronary artery bypass grafting (CABG) to PCI among diabetics? 1

Wu:  It makes perfect sense. There are other reports evaluating PCI in patients within high risk categories, including those with small diameter vessels, diabetes, and extensive, systemic vascular disease, showing unacceptably high rates of restenosis with bare metal stents (30%-60%) and DESs (6%-18%) 2-4.  We also know first-hand using an inbred rat strain that develops macrovascular disease 4 months after onset of spontaneous diabetes.  In our experiment model, just 4weeks following balloon-induced injury to the coratid artery (PTCA),  we observed 2x greater restenosis in female obese rats, and 4x greater stenosis in obese, diabetic rats  littermates (syndrome X) relative to the non-obese, non-diabetic littermates.  These results predicted that obesity (dyslipidemia) and diabetes (severe hyperglycemia) were major risk factors promoting the complication of restenosis (Wu and Kislauskis, unpublished).

Kislauskis: Can you tell our readers a bit more about the significance of restenosis and thrombosis and the concept behind your approach.

Wu: Two significant drawbacks to conventional PCI are the need for costly, long-term anti-platelet therapy; and having a metal artifact within the coronary vessel. In fact, once installed, the purpose of DES is to maintain patency and provide a scaffold until remodeling is complete, maybe 6 months.  The period of drug elution is typically shorter in duration.  In the event of restenosis, a second DES procedure is recommended and performed with satisfactory results.  However, leaving another metal artifact is problematic.

Most concerning to PCI patients, however, should be an increased risk of sudden death from heart attack from a clot (thrombosis) and tissue ischemia (myocardial infarction).  No available DES technology (eg. Cypher®or Taxus® DES) demonstrates any advantage over bare metal stents in this regard 5-7.  So the thinking is a metal artifact create an irregular vessel surface and micro-eddys in blood flow which ultimately result in late-stage thrombosis, particularly in patients who go off anti-their platelet therapy too soon 8.  Therefore and conceptually, by combining potent DES technology with a fully-biodegradable scaffold, designed to be absorbed fully into the tissue, likely will reduce the rate in-stent stenosis and prevents late-stage thrombosis.

Kislauskis: How did you come up with your unique polymer formulation?

Wu: It turns out that through a process of trial and error in the lab I was able to identify a biodegradable formulation which reduces the local inflammatory response common to all DES formulations while improving the stent’s radial strength.  With a stable drug delivery platform (BioDe®), the process of remodeling will contribute far less to restenosis.  Furthermore, and unlike all prior art, my BioDe® formulation can neutralize acidic intermediates generated during stent degradation that induce inflammation.  The combination of anti-restenosis drugs (Combo®) also is effective at inhibiting signaling pathways that contribute to restenosis.

Kislauskis:  How did you come to design the PowerStent®?

Wu: Again, a long process of trial and error, initially using computer applied design (CAD) principals I learned while earning attending a mechanical engineering certificate program at Wentworth Institute of Technology in Boston. Elements behind my concept for BioDe® came to me while I was involved in a home renovation project, working with grout.  Although the formulation is simple and may be duplicated, the process of manufacturing is complicated.

Kislauskis: So it’s your trade secret.

Wu: Absolutely.

Kislauskis: Can you summary its other advantages and your plans to commercialize the PowerStent®?

Wu: Preclinical, short duration (30 day) studies in porcine models with the PowerStent® Absorb deployed indicate that it will be non-inferior to the current metal DES and competing biodegradable stent technologies. Important functional attributes of the BioDe® polymer include better biocompatibility (less inflammatory), excellent radial strength, potent anti-restenosis activity, and a unique microporous surface that promotes integration into neointimal layer of stented vessel.  Ongoing and much longer duration studies may also support our contention that this design can reduce risks of late-stage in-stent thrombosis.

Kislauskis: What path and difficulties to you foresee in obtaining a regulatory approval to conduct clinical trials with the PowerStent® Absorb?

Wu:  FDA Guidance to commercialize conventional DES technology is available. Unfortunately, no guidance is published for a fully-biodegradable stent.  Therefore, I anticipate seeking advice from the regulatory bodies prior to petitioning for approval to perform clinical trials.  It will no doubt be a complicated process as this technology involves a novel drug combination (albeit FDA-approved drugs), and a novel formulation (albeit FDA-approved components), and a novel indwelling and bioabsorbable medical device (stent).  We are presently completing several required engineering studies for the final phase of pre-clinical safety and efficacy testing, in China. The goals are to obtain FDA pre-market and NDA approvals, and to receive a CE mark from major international markets including Europe and the BRICK nations.

Kislauskis: How will you commercialize this 3rd generation, fully-biodegradable stent?

Wu: There are likely 3 scenarios to complete development and commercialization.  One involves securing bridge funding from the NIH SBIR program, supplemented with angel financing to complete preclinical program. I project that a minimum of $6 Million (USD) will be required to complete regulatory approval and pivotal clinical trials.  Therefore, it is conceivable that a Series A round of equity financing from venture capitalists, in either US or China, will be required. A third scenario is to partner or sell the technology to a major player in this space to complete clinical testing and commercialization. Potential partners include Boston Scientific Company, J&J, etc. Any of these partners could facilitate the processes of regulatory approval, manufacturing, global distribution and marketing.  Discussions are underway with one such prospective partner and with several VC groups.

Kislauskis: What is its likely impact of this product on patient care and the field of interventional cardiology?

Wu: According to US statistics, approximately 14 million Americans suffer from CAD, and 500,000 people die from acute myocardial infarction. One million more survive but with a 1.5 to 15 times greater risk of mortality or morbidity than the rest of the population each year.  In the U.S., the annual health care costs of CAD are estimated to be in excess of $112 billion, and the estimated annual total direct cost associated with PCI with stents is over $2 billion.  I anticipate that our PowerStent® Absorb stent will be competitive in a marketplace estimated to be over $5 billion in 2010. Although CAD patients are the primary market, other related applications for our PowerStent Absorb technology include peripheral arteries, intracerebral vascular and small vessels which are also significant.

Kislauskis:  Thank you for your contribution to this site.  For more information about MMG, LLC and Dr. Wu’s technology please refer to his publications 9-13 or contact him directly at tiangenwu@yahoo.com.

REFERENCES

1.   Mark A. Hlatky, M.D. Compelling Evidence for Coronary-Bypass Surgery in Patients with Diabetes.   N Engl J Med 2012; 367:2437-2438.

2.  Stamler, J. (1989) Epidemiology.  Established major risk factors, and the primary prevention of coronary heart disease. In: Chatterjee K, Karliner J, Rapaport E, Cheitlin MD, Parmlee WW, Sheinman, M eds. Cardiology, Philadelphia Penn: JB Lippincott, 1991, 7.2-7.35. (volume 2).

3. Tanabe, K, Regar, E et al.  Sirolimus-eluting stent for treatment of in-stentrestenosis: One-year angiographic and intravascular ultrasound follow-up. J. Am Col.Cardi.   (2003) 41: 12A.

4. Grube, Eberhard;  Silber, Sigmund.  Six- and twelve-month results from a randomized, double-blind trial on a slow-release paclitaxel-eluting stent for de novo coronary lesions. Circulation 2003: 107, 38-42.

5.  Iakovou I, Schmidt T, Bonizzoni E, et al. Incidence, predictors, and outcome of thrombosis after successful implantation of drug-eluting stents. JAMA 2005;293:2126–2130.

6.  Ong AT, McFadden EP, Regar E, et al. Late angiographic stent thrombosis (LAST) events with drug-eluting stents. J Am Coll Cardiol 2005;45:2088–2092.

7. Wang F, Stouffer GA, Waxman S, et al. Late coronary stent thrombosis: Early vs late stent thrombosis in the stent era. Catheter Cardiovasc Interven 2002;55:142–147.

8. McFadden EP, Stabile E, Regar E, et al. Late thrombosis in drug-eluting coronary stents after discontinuation of antiplatelet therapy. Lancet 2004;364:1519–1521.

9. Ma X, Oyamada S, Wu T, Robich MP, Wu H, Wang X, Buchholz B, McCarthy S, Bianchi CF, Sellke FW, Laham R. In vitro and in vivo degradation of poly(D, L-lactide-co-glycolide)/amorphous calcium phosphate copolymer coated on metal stents. J Biomed Mater Res A. 2011 Mar 15;96(4):632-8. doi: 10.1002/jbm.a.33016. Epub 2011 Jan 25.

10. Oyamada S, Ma X, Wu T, Robich MP, Wu H, Wang X, Buchholz B, McCarthy S, Bianchi CF, Sellke FW, Laham R. Trans-iliac rat aorta stenting: a novel high throughput preclinical stent model for restenosis and thrombosis. J Surg Res. 2011 Mar;166(1):e91-5. Erratum in: J Surg Res. 2012 May 1;174(1):184.

11. Ma X, Oyamada S, Gao F, Wu T, Robich MP, Wu H, Wang X, Buchholz B, McCarthy S, Gu Z, Bianchi CF, Sellke FW, Laham R Paclitaxel/sirolimus combination coated drug-eluting stent: in vitro and in vivo drug release studies. J Pharm Biomed Anal. 2011 Mar 25;54(4):807-11. Erratum in: J Pharm Biomed Anal. 2012 Feb 5;59:217.

12. Ma X, Wu T, Robich MP, Wang X, Wu H, Buchholz B, McCarthy S. Drug-eluting stents. Int J Clin Exp Med. 2010 Jul 15;3(3):192-201.

Other articles related to this subject were published in this Open Access OnlIne Scientific Journal:

Lev-Ari, A. (2012aa). Renal Sympathetic Denervation: Updates on the State of Medicine

https://pharmaceuticalintelligence.com/2012/12/31/renal-sympathetic-denervation-updates-on-the-state-of-medicine/

 

Lev-Ari, A. (2012U). Imbalance of Autonomic Tone: The Promise of Intravascular Stimulation of Autonomics

https://pharmaceuticalintelligence.com/2012/09/02/imbalance-of-autonomic-tone-the-promise-of-intravascular-stimulation-of-autonomics/

Lev-Ari, A. (2012R). Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents https://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

 

Lev-Ari, A. (2012K). Percutaneous Endocardial Ablation of Scar-Related Ventricular Tachycardia

https://pharmaceuticalintelligence.com/2012/07/18/percutaneous-endocardial-ablation-of-scar-related-ventricular-tachycardia/

 

Lev-Ari, A. (2012C). Treatment of Refractory Hypertension via Percutaneous Renal Denervation

https://pharmaceuticalintelligence.com/2012/06/13/treatment-of-refractory-hypertension-via-percutaneous-renal-denervation/

Lev-Ari, A. (2012D). Competition in the Ecosystem of Medical Devices in Cardiac and Vascular Repair: Heart Valves, Stents, Catheterization Tools and Kits for Open Heart and Minimally Invasive Surgery (MIS)

https://pharmaceuticalintelligence.com/2012/06/22/competition-in-the-ecosystem-of-medical-devices-in-cardiac-and-vascular-repair-heart-valves-stents-catheterization-tools-and-kits-for-open-heart-and-minimally-invasive-surgery-mis/

Lev-Ari, A. (2012E). Executive Compensation and Comparator Group Definition in the Cardiac and Vascular Medical Devices Sector: A Bright Future for Edwards Lifesciences Corporation in the Transcatheter Heart Valve Replacement Market

https://pharmaceuticalintelligence.com/2012/06/19/executive-compensation-and-comparator-group-definition-in-the-cardiac-and-vascular-medical-devices-sector-a-bright-future-for-edwards-lifesciences-corporation-in-the-transcatheter-heart-valve-replace/

 

Lev-Ari, A. (2012F). Global Supplier Strategy for Market Penetration & Partnership Options (Niche Suppliers vs. National Leaders) in the Massachusetts Cardiology & Vascular Surgery Tools and Devices Market for Cardiac Operating Rooms and Angioplasty Suites

https://pharmaceuticalintelligence.com/2012/06/22/global-supplier-strategy-for-market-penetration-partnership-options-niche-suppliers-vs-national-leaders-in-the-massachusetts-cardiology-vascular-surgery-tools-and-devices-market-for-car/

 

Lev-Ari, A. (2012G).  Heart Remodeling by Design: Implantable Synchronized Cardiac Assist Device: Abiomed’s Symphony

https://pharmaceuticalintelligence.com/2012/07/23/heart-remodeling-by-design-implantable-synchronized-cardiac-assist-device-abiomeds-symphony/

 

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Coronary artery disease in symptomatic patients referred for coronary angiography: Predicted by Serum Protein Profiles

Reporter: Aviva Lev-Ari, PhD, RN
BMC Med. 2012 Dec 5;10(1):157. [Epub ahead of print]

Serum protein profiles predict coronary artery disease in symptomatic patients referred for coronary angiography.

Laframboise WADhir RKelly LAPetrosko PKrill-Burger JMSciulli CMLyons-Weiler MAChandran URLomakin AMasterson RVMarroquin OC,Mulukutla SRMcNamara DM.

ABSTRACT:

BACKGROUND: More than a million diagnostic cardiac catheterizations are performed annually in the US for evaluation of coronary artery anatomy and the presence of atherosclerosis. Nearly half of these patients have no significant coronary lesions or do not require mechanical or surgical revascularization. Consequently, the ability to rule out clinically significant coronary artery disease (CAD) using low cost, low risk tests of serum biomarkers in even a small percentage of patients with normal coronary arteries could be highly beneficial.

METHODS:

Serum from 359 symptomatic subjects referred for catheterization was interrogated for proteins involved in atherogenesis, atherosclerosis, and plaque vulnerability. Coronary angiography classified 150 patients without flow-limiting CAD who did not require percutaneous intervention (PCI) while 209 required coronary revascularization (stents, angioplasty, or coronary artery bypass graft surgery). Continuous variables were compared across the two patient groups for each analyte including calculation of false discovery rate (FDR [less than or equal to]1%) and Q value (P value for statistical significance adjusted to [less than or equal to]0.01).

RESULTS:

Significant differences were detected in circulating proteins from patients requiring revascularization including increased apolipoprotein B100 (APO-B100), C-reactive protein (CRP), fibrinogen, vascular cell adhesion molecule 1 (VCAM-1), myeloperoxidase (MPO), resistin, osteopontin, interleukin (IL)-1beta, IL-6, IL-10 and N-terminal fragment protein precursor brain natriuretic peptide (NT-pBNP) and decreased apolipoprotein A1 (APO-A1). Biomarker classification signatures comprising up to 5 analytes were identified using a tunable scoring function trained against 239 samples and validated with 120 additional samples. A total of 14 overlapping signatures classified patients without significant coronary disease (38% to 59% specificity) while maintaining 95% sensitivity for patients requiring revascularization. Osteopontin (14 times) and resistin (10 times) were most frequently represented among these diagnostic signatures. The most efficacious protein signature in validation studies comprised osteopontin (OPN), resistin, matrix metalloproteinase 7 (MMP7) and interferon gamma (IFNgamma) as a four-marker panel while the addition of either CRP or adiponectin (ACRP-30) yielded comparable results in five protein signatures.

CONCLUSIONS:

Proteins in the serum of CAD patients predominantly reflected (1) a positive acute phase, inflammatory response and (2) alterations in lipid metabolism, transport, peroxidation and accumulation. There were surprisingly few indicators of growth factor activation or extracellular matrix remodeling in the serum of CAD patients except for elevated OPN. These data suggest that many symptomatic patients without significant CAD could be identified by a targeted multiplex serum protein test without cardiac catheterization thereby eliminating exposure to ionizing radiation and decreasing the economic burden of angiographic testing for these patients.

 
 SOURCE:

Other related articles on this Open Access Online Scientific Journal:

 

Assessing Cardiovascular Disease with Biomarkers

https://pharmaceuticalintelligence.com/2012/12/25/assessing-cardiovascular-disease-with-biomarkers/#comment-6990

 

To Stent or Not? A Critical Decision

https://pharmaceuticalintelligence.com/2012/10/23/to-stent-or-not-a-critical-decision/

Obstructive coronary artery disease diagnosed by RNA levels of 23 genes – CardioDx heart disease test wins Medicare coverage

https://pharmaceuticalintelligence.com/2012/08/14/obstructive-coronary-artery-disease-diagnosed-by-rna-levels-of-23-genes-cardiodx-heart-disease-test-wins-medicare-coverage/

 

https://pharmaceuticalintelligence.com/?s=PCI

 

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Reporter: Aviva Lev-Ari, PhD, RN

International Consortium Finds 15 Novel Risk Loci for Coronary Artery Disease

“lipid metabolism and inflammation as key biological pathways involved in the genetic pathogenesis of CAD”

Themistocles Assimes from Stanford University Medical Center said in a statement that these findings begin to clear up its role. “Our network analysis of the top approximately 240 genetic signals in this study seems to provide evidence that genetic defects in some pathways related to inflammation are a cause,” he said.

On this Open Access Online Scientific Journal, lipid metabolism and inflammation were researched and exposed in the following entries.

However, it is ONLY,  these 15 Novel Risk Loci for Coronary Artery Disease published on 12/3/2012 that provides the genomics loci and the genetic explanation for the following empirical results obtained in the recent research on Cardiovascular diseases, as present in the second half of this post, below.

Special Considerations in Blood Lipoproteins, Viscosity, Assessment and Treatment

https://pharmaceuticalintelligence.com/2012/11/28/special-considerations-in-blood-lipoproteins-viscosity-assessment-and-treatment/

What is the role of plasma viscosity in hemostasis and vascular disease risk?

https://pharmaceuticalintelligence.com/2012/11/28/what-is-the-role-of-plasma-viscosity-in-hemostasis-and-vascular-disease-risk/

PIK3CA mutation in Colorectal Cancer may serve as a Predictive Molecular Biomarker for adjuvant Aspirin therapy

https://pharmaceuticalintelligence.com/2012/11/28/pik3ca-mutation-in-colorectal-cancer-may-serve-as-a-predictive-molecular-biomarker-for-adjuvant-aspirin-therapy/

Peroxisome proliferator-activated receptor (PPAR-gamma) Receptors Activation: PPARγ transrepression for Angiogenesis in Cardiovascular Disease and PPARγ transactivation for Treatment of Diabetes

https://pharmaceuticalintelligence.com/2012/11/13/peroxisome-proliferator-activated-receptor-ppar-gamma-receptors-activation-pparγ-transrepression-for-angiogenesis-in-cardiovascular-disease-and-pparγ-transactivation-for-treatment-of-dia/

Positioning a Therapeutic Concept for Endogenous Augmentation of cEPCs — Therapeutic Indications for Macrovascular Disease: Coronary, Cerebrovascular and Peripheral

https://pharmaceuticalintelligence.com/2012/08/29/positioning-a-therapeutic-concept-for-endogenous-augmentation-of-cepcs-therapeutic-indications-for-macrovascular-disease-coronary-cerebrovascular-and-peripheral/

Cardiovascular Risk Inflammatory Marker: Risk Assessment for Coronary Heart Disease and Ischemic Stroke – Atherosclerosis.

https://pharmaceuticalintelligence.com/2012/10/30/cardiovascular-risk-inflammatory-marker-risk-assessment-for-coronary-heart-disease-and-ischemic-stroke-atherosclerosis/

The Essential Role of Nitric Oxide and Therapeutic NO Donor Targets in Renal Pharmacotherapy

https://pharmaceuticalintelligence.com/2012/11/26/the-essential-role-of-nitric-oxide-and-therapeutic-no-donor-targets-in-renal-pharmacotherapy/

Nitric Oxide Function in Coagulation

https://pharmaceuticalintelligence.com/2012/11/26/nitric-oxide-function-in-coagulation/Nitric Oxide Function in Coagulation

15 Novel Risk Loci for Coronary Artery Disease

December 03, 2012

NEW YORK (GenomeWeb News) – A large-scale association analysis of coronary artery disease has detected 15 new loci associated with risk of the disease, bringing the total number of known risk alleles to 46. As the international CARDIoGRAMplusC4D Consortium reported in Nature Genetics yesterday, the study also found that lipid metabolism and inflammation pathways may play a part in coronary artery disease pathogenesis.

“The number of genetic variations that contribute to heart disease continues to grow with the publication of each new study,” Peter Weissberg from the British Heart Foundation, a co-sponsor of the study, said in a statement. “This latest research further confirms that blood lipids and inflammation are at the heart of the development of atherosclerosis, the process that leads to heart attacks and strokes.”

For its study, the consortium, which was comprised of more than 180 researchers, performed a meta-analysis of data from the 22,233 cases and 64,762 controls of the CARDIoGRAM genome-wide association study and of the 41,513 cases and 65,919 controls from 34 additional studies of people of European and South Asian descent. Using the custom Metabochip array from Illumina, the team tested SNPs for disease association in those populations. The SNPs that reached significance in that stage of the study were then replicated using data from a further four studies.

From this, the team identified 15 new loci with genome-wide significance for risk of coronary artery disease, in addition to known risk loci.

The consortium also reported an additional 104 SNPs that appeared to be associated with coronary artery disease but did not meet the cut-off for genome-wide significance.

Then looking to other known risk factors for coronary artery disease, like blood pressure and diabetes, the researchers assessed whether any of those risk factors were associated with the risk loci. Of the 45 known risk loci, 12 were associated with blood lipid content and five with blood pressure. And while people with type 2 diabetes have a higher risk of developing coronary artery disease, none of the known risk loci were linked to diabetic traits.

An analysis of the pathways that SNPs linked to coronary artery disease fall in revealed that many of them are involved in lipid metabolism and inflammation pathways — 10 risk loci were found to be involved in lipid metabolism. “Our network analysis identified lipid metabolism and inflammation as key biological pathways involved in the genetic pathogenesis of CAD,” the researchers wrote in the paper. “Indeed, there was significant crosstalk between the lipid metabolism and inflammation pathways identified.”

The role of inflammation in coronary artery disease has been up for debate — a debate centering on whether it is a cause or a consequence of the disease — and study author Themistocles Assimes from Stanford University Medical Center said in a statement that these findings begin to clear up its role. “Our network analysis of the top approximately 240 genetic signals in this study seems to provide evidence that genetic defects in some pathways related to inflammation are a cause,” he said.

Related Stories

SOURCE:

http://www.genomeweb.com//node/1159041?hq_e=el&hq_m=1424172&hq_l=3&hq_v=09187c3305

 

GWAS, Meta-Analyses Uncover New Coronary Artery Disease Risk Loci

March 07, 2011

By a GenomeWeb staff reporter

NEW YORK (GenomeWeb News) – Three new studies — including the largest meta-analysis yet of coronary artery disease — have identified dozens of coronary artery disease risk loci in European, South Asian, and Han Chinese populations. All three papers appeared online yesterday in Nature Genetics.

For the first meta-analysis, members of a large international consortium known as the Coronary Artery Disease Genome-wide Replication and Meta-Analysis study, or CARDIoGRAM, sifted through data on more than 135,000 individuals from the UK, US, Europe, Iceland, and Canada. In so doing, they tracked down nearly two-dozen new and previously reported coronary artery disease risk loci.

Because only a few of these loci have been linked to other heart disease-related risk factors such as high blood pressure, those involved say the work points to yet unexplored heart disease pathways.

“[W]e have discovered several new genes not previously known to be involved in the development of coronary heart disease, which is the main cause of heart attacks,” co-corresponding author Nilesh Samani, a cardiology researcher affiliated with the University of Leicester and Glenfield Hospital, said in a statement. “Understanding how these genes work, which is the next step, will vastly improve our knowledge of how the disease develops, and could ultimately help to develop new treatments.”

Samani and his co-workers identified the loci by bringing together data on 22,233 individuals with coronary artery disease and 64,762 unaffected controls. The participants, all of European descent, had been sampled through 14 previous genome-wide association studies and genotyped at an average of about 2.5 million SNPs each. The team then assessed the top candidate SNPs found in this initial analysis in another 56,582 individuals (roughly half of whom had coronary artery disease).

The search not only confirmed associations between coronary artery disease and 10 known loci, but also uncovered associations with 13 other loci. All but three of these were distinct from loci previously implicated in other heart disease risk factors such as hypertension or cholesterol levels, researchers noted.

Consequently, those involved in the study say that exploring the biological functions of the newly detected genes could offer biological clues about how heart disease develops — along with strategies for preventing and treating it.

The genetic complexity of coronary artery disease being revealed by such studies has diagnostic implications as well, according to some.

“Each new gene identified brings us a small step closer to understanding the biological mechanisms of cardiovascular disease development and potential new treatments,” British Heart Foundation Medical Director Peter Weissberg, who was not directly involved in the new studies, said in a statement. “However, as the number of genes grows, it takes us further away from the likelihood that a simple genetic test will identify those most of risk of suffering a heart attack or a stroke.”

Meanwhile, researchers involved with Coronary Artery Disease Genetics Consortium did their own meta-analysis using data collected from four GWAS to find five coronary artery-associated loci in European and South Asian populations.

The group initially looked at 15,420 individuals with coronary artery disease — including 6,996 individuals from South Asia and 8,424 from Europe — and 15,062 unaffected controls. Participants were genotyped at nearly 575,000 SNPs using Illumina BeadChips. Most South Asian individuals tested came from India and Pakistan, researchers noted, while European samples came from the UK, Italy, Sweden, and Germany.

For the validation phase of the study, the team focused in on 59 SNPs at 50 loci from the discovery group that seemed most likely to yield authentic new disease associations. These variants were assessed in 10 replication groups comprised of 21,408 individuals with coronary artery disease and 19,185 individuals without coronary artery disease.

All told, researchers found five loci that seem to influence coronary artery disease risk in the European and South Asian populations: one locus each on chromosomes 7, 11, and 15, along with a pair of loci on chromosome 10.

The team didn’t see significant differences in the frequency or effect sizes of these newly identified variants between the European and South Asian populations, though they emphasized that their approach may have missed some potential risk variants, particularly in those of South Asian descent.

“[C]urrent genome-wide arrays may not capture all important variants in South Asians,” they explained, “Nevertheless, all of the known and new variants were significantly associated with [coronary artery disease] risk in both the European and South Asian populations in the current study, indicating the importance of genes associated with [coronary artery disease] beyond the European ancestry groups in which they were first defined.”

Finally, using a three-stage discovery, validation, and replication GWAS approach, Chinese researchers identified a single coronary artery disease risk variant in the Han Chinese population.

In this first phase of that study, researchers tested samples from 230 cases and 230 controls from populations in Beijing and in China’s Hubei province that were genotyped at Genentech and CapitalBio using Affymetrix Human SNP5.0 arrays.

From the nearly three-dozen SNPs identified in the first stage of the study, they narrowed in on nine suspect variants. After finding linkage disequilibrium between two of the variants, they did validation testing on eight of these in 572 individuals with coronary artery disease and 436 unaffected controls, all from Hubei province.

That analysis implicated a single chromosome 6 SNP called rs6903956 in coronary artery disease — a finding the team ultimately replicated in another group of 2,668 coronary artery disease cases and 3,917 controls from three independent populations in Hubei, Shandong province, and northern China.

The team’s subsequent experiments suggest that the newly detected polymorphism, which falls within a putative gene called C6orf105 on chromosome 6, curbs the expression of this gene. The functional consequences of this shift in expression, if any, are yet to be determined.

Because C6orf105 shares some identity and homology with an androgen hormone inducible gene known as AIG1, those involved in the study argue that it may be worthwhile to investigate possible ties between C6orf105 expression, androgen signaling, and coronary artery disease.

“Androgen has previously been reported to be associated the pathogenesis of atherosclerosis,” they wrote. “Future studies are needed to explore whether C6orf105 expression can be induced by androgen and to further determine the potential mechanism of [coronary artery disease] associated with decreased C6orf105 expression.”

 SOURCE:

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Absorb™ Bioresorbable Vascular Scaffold: An International Launch by Abbott Laboratories

Reporter: Aviva Lev-Ari, PhD, RN

 

Abbott Laboratories (ABT) Announces International Launch of the Absorb™ Bioresorbable Vascular Scaffold

9/25/2012 10:26:30 AM

ABBOTT PARK, Ill., Sept. 25, 2012 /PRNewswire/ — Abbott (NYSE: ABT) announced today that Absorb, the world’s first drug eluting bioresorbable vascular scaffold (BVS), is now widely available across Europe and parts of Asia Pacific and Latin America. Absorb is a first-of-its-kind device for the treatment of coronary artery disease (CAD). It works by restoring blood flow to the heart similar to a metallic stent, but then dissolves into the body, leaving behind a treated vessel that may resume more natural function and movement because it is free of a permanent metallic stent. Absorb is made of polylactide, a naturally dissolvable material that is commonly used in medical implants such as dissolving sutures.

The potential long-term benefits of a scaffold that dissolves are significant. The vessel may expand and contract as needed to increase the flow of blood to the heart in response to normal activities such as exercising; treatment and diagnostic options are broadened; the need for long-term treatment with anti-clotting medications may be reduced; and future interventions would be unobstructed by a permanent implant.

“This innovation represents a true paradigm shift in how we treat coronary artery disease. With the launch of Absorb, a scaffold that disappears after doing its job is no longer a dream, but a reality,” said Patrick W. Serruys, M.D., Ph.D., professor of interventional cardiology at the Thoraxcentre, Erasmus University Hospital, Rotterdam, the Netherlands. “Patients are excited about Absorb since it may allow blood vessels to return to a more natural state and expand long-term diagnostic and treatment options.”

The international launch of Absorb is supported by a robust clinical trial program that encompasses five studies in more than 20 countries around the world. Study data indicate that Absorb performs similar to a best-in-class drug eluting stent across traditional measures such as major adverse cardiovascular events (MACE) and target lesion revascularization (TLR), while providing patients with the added benefits associated with a device that dissolves over time. As the Absorb scaffold dissolves, vascular function is potentially restored to the blood vessel, allowing more blood to flow through the vessel as the body requires.

“Absorb is a leading example of Abbott’s dedication to advancing patient outcomes through innovative technology. Abbott has remained committed to meeting the growing physician and patient demand for a bioresorbable vascular scaffold from the initial device developed nearly 10 years ago to the expansion of our manufacturing capabilities to support this international launch,” said John M. Capek, executive vice president, Medical Devices, Abbott. “We are proud to be the first company to commercialize a drug eluting bioresorbable vascular scaffold, which has the potential to revolutionize the way physicians treat their patients with coronary artery disease.”

Heart disease is the leading cause of death for men and women around the world, and CAD is the most common type of heart disease.1,2 CAD occurs when arteries that supply blood to the heart become narrowed or blocked, leading to chest pain or shortness of breath and increased risk of heart attack.

About the Absorb Bioresorbable Vascular Scaffold

Absorb is now available in a broad size matrix to support the needs of physicians treating patients with CAD.

The Absorb bioresorbable vascular scaffold, similar to a small mesh tube, is designed to open a blocked heart vessel and restore blood flow to the heart. Absorb is referred to as a scaffold to indicate that it is a temporary structure, unlike a stent, which is a permanent implant. The scaffold provides support to the vessel until the artery can stay open on its own, and then dissolves naturally. Absorb leaves patients with a vessel free of a permanent metallic stent and may allow the vessel to resume more natural function and movement, enabling long-term benefits.3,4

Abbott’s BVS delivers everolimus, an anti-proliferative drug used in Abbott’s XIENCE coronary stent systems. Everolimus was developed by Novartis Pharma AG and is licensed to Abbott by Novartis for use on its drug eluting vascular devices. Everolimus has been shown to inhibit in-stent neointimal growth in the coronary vessels following stent implantation, due to its anti-proliferative properties.

Absorb is neither approved nor authorized for sale and currently is in development with no regulatory status in the United States. Absorb is authorized for sale in CE Mark countries. Absorb is now available in Europe, the Middle East, parts of Asia Pacific, including Hong Kong, Singapore, Malaysia and New Zealand, and parts of Latin America.

About Abbott Vascular

Abbott Vascular is the world’s leader in drug eluting stents. Abbott Vascular has an industry-leading pipeline and a comprehensive portfolio of market-leading products for cardiac and vascular care, including products for coronary artery disease, vessel closure, endovascular disease and structural heart disease.

About Abbott

Abbott is a global, broad-based health care company devoted to the discovery, development, manufacture and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs approximately 91,000 people and markets its products in more than 130 countries.

Abbott’s news releases and other information are available on the company’s Web site at www.abbott.com.

1The top 10 causes of death, World Health Organization. June 2011 Available at: http://www.who.int/mediacentre/factsheets/fs310/en/index.html 2 Coronary Artery Disease. National Heart, Lung and Blood Institute. May 2011 Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/cad/ 3Absorb completely dissolves except for two pairs of tiny metallic markers, which help guide placement and remain in the artery to enable a physician to see where the device was placed.4Early evidence indicates natural vessel function is possible to achieve improved long term outcomes. Absorb is a trademark of the Abbott Group of Companies.

On this Scientific Web Site the, Cardiovascular Medical Devices are addressed in the following posts:

Lev-Ari, A. (2012U). Imbalance of Autonomic Tone: The Promise of Intravascular Stimulation of Autonomics

https://pharmaceuticalintelligence.com/2012/09/02/imbalance-of-autonomic-tone-the-promise-of-intravascular-stimulation-of-autonomics/

 

Lev-Ari, A. (2012R). Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents https://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

 

Lev-Ari, A. (2012K). Percutaneous Endocardial Ablation of Scar-Related Ventricular Tachycardia

https://pharmaceuticalintelligence.com/2012/07/18/percutaneous-endocardial-ablation-of-scar-related-ventricular-tachycardia/

 

Lev-Ari, A. (2012C). Treatment of Refractory Hypertension via Percutaneous Renal Denervation

https://pharmaceuticalintelligence.com/2012/06/13/treatment-of-refractory-hypertension-via-percutaneous-renal-denervation/

 

Lev-Ari, A. (2012D). Competition in the Ecosystem of Medical Devices in Cardiac and Vascular Repair: Heart Valves, Stents, Catheterization Tools and Kits for Open Heart and Minimally Invasive Surgery (MIS)

https://pharmaceuticalintelligence.com/2012/06/22/competition-in-the-ecosystem-of-medical-devices-in-cardiac-and-vascular-repair-heart-valves-stents-catheterization-tools-and-kits-for-open-heart-and-minimally-invasive-surgery-mis/

 

Lev-Ari, A. (2012E). Executive Compensation and Comparator Group Definition in the Cardiac and Vascular Medical Devices Sector: A Bright Future for Edwards Lifesciences Corporation in the Transcatheter Heart Valve Replacement Market

https://pharmaceuticalintelligence.com/2012/06/19/executive-compensation-and-comparator-group-definition-in-the-cardiac-and-vascular-medical-devices-sector-a-bright-future-for-edwards-lifesciences-corporation-in-the-transcatheter-heart-valve-replace/

 

Lev-Ari, A. (2012F). Global Supplier Strategy for Market Penetration & Partnership Options (Niche Suppliers vs. National Leaders) in the Massachusetts Cardiology & Vascular Surgery Tools and Devices Market for Cardiac Operating Rooms and Angioplasty Suites

https://pharmaceuticalintelligence.com/2012/06/22/global-supplier-strategy-for-market-penetration-partnership-options-niche-suppliers-vs-national-leaders-in-the-massachusetts-cardiology-vascular-surgery-tools-and-devices-market-for-car/

 

Lev-Ari, A. (2012G).  Heart Remodeling by Design: Implantable Synchronized Cardiac Assist Device: Abiomed’s Symphony

https://pharmaceuticalintelligence.com/2012/07/23/heart-remodeling-by-design-implantable-synchronized-cardiac-assist-device-abiomeds-symphony/

 

SOURCE Abbott

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