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Archive for the ‘Electrophysiology’ Category


Cardiac Medical Devices Pioneer, Earl E. Bakken, Medtronic Co-founder, the developer of the first external, battery-powered, transistorized pacemaker, died at 94 on 10/21/2018 in Hawaii

Reporter: Aviva Lev-Ari, PhD, RN

 

Earl Bakken was born to Florence and Osval Bakken on January 10, 1924, in Minneapolis. After serving as a radar instructor in World War II, Bakken earned a degree in electrical engineering at the University of Minnesota.

In the late 1950’s, Bakken developed the first external, wearable, battery-powered, transistorized heart pacemaker, and commercialized the first implantable pacemaker in 1960. Medtronic grew rapidly from there; today its medical products and devices improve the lives of two people every second.

Earl with five-year-old pacemaker recipient Lyla Koch in 1984

Image Sourcehttp://www.medtronic.com/us-en/about/news/celebrating-earl-bakken.html

CELEBRATING EARL BAKKEN

Legendary Medtronic co-founder passes away in Hawaii.

Earl Bakken, Co-founder, Medtronic, died at 94

Image Sourcehttp://www.medtronic.com/us-en/about/news/celebrating-earl-bakken.html

The business struggled, but while servicing medical equipment, Bakken and Hermundslie built relationships with doctors at university hospitals in Minneapolis. There they met C. Walton Lillehei, a young staff surgeon who would later become famous for pioneering open-heart surgery. Following a blackout in the Twin Cities that caused the death of an infant, Lillehei asked Bakken to come up with a solution. He responded by adapting a circuit described in Popular Electronics magazine to create the first external wearable, battery-powered pacemaker, replacing the large, alternating current-powered pacemakers that were in use at the time.

The original Medtronic "Garage Gang" poses in front of Medtronic Operational Headquarters in Fridley, Minnesota.

The Garage Gang

Standing: Dale Blosberg, Norman Hagfors, Earl Hatten. Seated: John Bravis, Earl Bakken, Louis Leisch

They expanded services to other medical technology. Then in 1960, the first implantable pacemaker was implanted in a human patient. Bakken and Hermundslie reached a licensing agreement with the inventors, giving their small company exclusive manufacturing and marketing rights to the device, and Medtronic took off.

“Earl always had a vision of healthcare of not being about devices, about drugs, but about restoring people to full health,” said former Medtronic CEO Bill George. “And so from the very start he was focused on not implanting a device, but enabling people to live a full active life and he delivered that point of view to all Medtronic employees through The Mission.

A lifelong aspiration came true for Bakken in 2013, when Medtronic Philanthropy launched The Bakken Invitation to honor people who received medical devices, and who made an impact on the lives of others, through service and volunteerism. Bakken, who in his later years became a medical device patient, with a pacemaker, coronary stents and insulin pump, was fond of asking patients what they planned to do with their gift of “extra life.” Each year Bakken met with the honorees. “Their stories are a powerful reminder that we can all give back-no matter our current situation,” he said after meeting them in 2014.

Earl poses with recipients of the Bakken Invitation in 2013.Earl with Bakken Invitation recipients in 2013

Every year in December, Medtronic employees gather to mark another Bakken inspiration — the employee holiday program. The company invites patients from all over the world to share their stories of how medical technology has improved their lives. Hundreds of employees fill the Medtronic conservatory for the event, while thousands of others listen or watch via Medtronic TV.

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Rhythm Management Device Hardware (Dual-chamber Pacemaker) coupled with BackBeat’s Cardiac Neuromodulation Therapy (CNT) bioelectronic therapy for Lowering Systolic Blood Pressure for patients with Pacemakers

Reporter: Aviva Lev-Ari, PhD, RN

 

BackBeat’s CNT is a bioelectronic therapy that immediately, substantially and chronically lowers blood pressure (BP) while simultaneously modulating the autonomic nervous system (ANS).  Mimicking the effects of multiple medications by reducing pre-load, after-load and sympathetic tone, it can be delivered using standard rhythm management device hardware such as dual-chamber pacemakers.

For more information: www.orchestrabiomed.com

October 2, 2018 — Two-year results of the Moderato I Study demonstrated immediate, substantial and sustained reduction in blood pressure when BackBeat cardiac neuromodulation therapy (CNT) was used in patients with persistent hypertension (office BP > 150mmHg). Patients in the study had persistent hypertension despite two or more anti-hypertensive medications and an indication for a pacemaker.

Results of the multicenter clinical trial were presented at the 2018 Transcatheter Cardiovascular Therapeutics (TCT) conference, Sept. 21-25 in San Diego, by Daniel Burkhoff, M.D., Ph.D., director, heart failure, hemodynamics and mechanical circulatory support research for the Cardiovascular Research Foundation (CRF).

“The clinical efficacy and safety data observed with BackBeat CNT in a patient population with a significant portion of isolated systolic disease is very promising. Hypertension affects over 70 percent of pacemaker patients. These patients could benefit substantially from a potent hypertension therapy such as BackBeat CNT that could be included in their already necessary pacemaker,” said Prof. Petr Neuzil, M.D., head of the Department of Cardiology of Na Homolce Hospital in Prague, Czech Republic and one of the principal investigators of the study.

The 27 patients that met the study inclusion criteria were implanted with BackBeat’s proprietary Moderato dual-chamber pacemaker that incorporates the BackBeat CNT algorithms. The primary safety and efficacy endpoint results of the study were as follows:

  • Efficacy Outcomes: Immediate, substantial and sustained reduction in blood pressure.
    • 14.2 mmHg decrease from baseline (p<0.001) in 24 hours ambulatory systolic blood pressure (AMB BP) at 3 months
    • 23.4 mmHg decrease from baseline (p < 0.001) in systolic blood pressure (SBP) sustained out to 2 years
  • High responder rate in a population where 78 percent of patients had isolated systolic hypertension.
    • 85 percent AMB BP reduced >5mmHg
    • 74 percent AMB BP reduced >10 mmHg
  • Safety Outcomes: The study met the safety endpoint.
    • Observed reduction in end systolic and diastolic volumes with no change to ejection fraction suggests improvement of cardiac function
    • Observed reduction in heart rate out to 2 years indicative of reduced sympathetic activity

“These statistically significant results demonstrate the potential for BackBeat CNT to be a broadly applicable therapy that substantially lowers blood pressure immediately and maintains reduced pressures for years,” commented Burkhoff. “It is rare to see a new therapy show such dramatic and sustained effects in such a small number of patients.”

To further investigate the efficacy and safety of BackBeat CNT for the treatment of hypertension, Orchestra BioMed is enrolling patients into a prospective, 1:1 randomized double-blind active treatment (BackBeat CNT) versus standard medical therapy trial, Moderato II. The study will enroll patients with uncontrolled blood pressure (office systolic > 140, day and AMB BP > 130 mmHg) treated with at least one anti-hypertension medication that are indicated for a dual-chamber pacemaker. The primary efficacy endpoint of the first cohort of the study is the comparison of the mean reduction in 24-hour systolic ambulatory blood pressure following 6 months of therapy between the treatment and the control. Primary safety endpoint is the rate of major adverse cardiac event (MACE) at 6 months between the treatment and control.  The company is expecting results on the first cohort of patients in 2019.

SOURCE

https://www.dicardiology.com/content/backbeat-cardiac-neuromodulation-therapy-reduces-blood-pressure-two-years?eid=333021707&bid=2258792

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Renowned Electrophysiologist Dr. Arthur Moss Died on February 14, 2018 at 86

Reporter: Aviva Lev-Ari, PhD, RN

 

— Stephen

Dr. Moss never lost the opportunity to get to know who an individual is by name, to complement one, to greet one, to teach one, to be available, and to show respect. His contributions to clinical medicine, patient care and physician education, along with pivotal research, is among the ver most notable of our era. I will miss him greatly and extend my most heartfelt gratitude to him and his family.

Stephen Winters, MD
Morristown Medical Center

Comments Section

 

Renowned Cardiologist Arthur J. Moss, Pioneer of Research and Treatment in Sudden Death, Passes Away

Friday, February 16, 2018

Arthur J. Moss, M.D.

Arthur J. Moss, M.D.

Cardiologist Arthur J. Moss, whose research saved hundreds of thousands of lives and improved the standard of care for legions of people with heart disease, died on February 14, 2018. He was 86.

During a career spanning six decades, Moss made some of the most significant and long-lasting discoveries in the prevention and treatment of sudden cardiac death. His astounding accomplishments in scientific research and clinical care stemmed especially from his special devotion to patients; he understood the importance of listening, building trust and working together to bring about change. He was also a skilled leader, able to foster meaningful collaborations that led to some of the most productive clinical trials in all of cardiology.

“Arthur was a man of absolute integrity, both of science and of character, and an amazing visionary who could see where the field of electrophysiology was headed long before others,” said Wojciech Zareba, M.D., Ph.D.,director of the Heart Research Follow-up Program at the University of Rochester Medical Center, who worked closely with Moss for the past 26 years. “He was eternally optimistic in all aspects of his life; he brought a positive attitude to everything he did and didn’t worry about the small stuff, which helped him accomplish great things.”

In 1958, as an intern at Massachusetts General Hospital, Moss planned to pursue a career in hematology. That summer he was called to serve in the United States Navy. When he arrived in Pensacola, Fla., his commanding officers thought he was a cardiologist, for reasons unbeknownst to him. They asked Moss to teach flight surgeons electrocardiography, a test known as an EKG that checks the electrical activity of the heart. Undaunted, he read multiple books on the topic and taught them. The intricacy of the heart’s electrical activity captured Moss’ interest and he never looked back.

Moss spent the first half of his career figuring out which patients were at high risk of sudden cardiac death and the second half finding the best ways to treat them. He became an eminent authority on common arrhythmias that afflict hundreds of thousands of adults with heart disease and often lead to sudden death, as well as rare heart rhythm disorders that are smaller in number but no less deadly.

An unexpected patient visit in 1970 started what Moss called the most rewarding part of his career: his life-long quest to help individuals with Long QT syndrome (LQTS). Doctors could not understand why this patient – a woman in her 30s – would suddenly fall unconscious when she got excited while bowling. An unusual EKG led Moss, then a young cardiologist at URMC, to diagnose LQTS. An uncommon genetic condition caused by a glitch in the heart’s electrical system, LQTS puts patients at high risk of arrhythmias, fainting spells and sudden death.

Moss devised the first effective surgical treatment for the disorder and had the foresight to create the International Long QT Syndrome Registry in 1979, one of the first rare disease registries in the world. The registry allowed Moss and colleagues to identify risk factors that enable early diagnosis; develop multiple treatment options that have achieved an 80 percent reduction in life-threatening events; and contribute to the discovery of multiple genes associated with the disorder. The National Institutes of Health has supported the registry since its creation, and in 2014 Moss received a NIH grant to fund the registry and associated research projects through 2019.

“Not only was Arthur extraordinary in understanding the immediate problem, but he was also visionary in that long before we knew how to analyze genes he started the registry and preserved blood samples that could be used in the future,” said Mark B. Taubman, M.D., CEO of URMC and dean of the School of Medicine and Dentistry. “The registry has become one of the most important repositories in the world, helping prevent thousands of untimely deaths from Long QT and enabling the in-depth investigation of how genetics influence a form of heart disease. The impact of his work is unparalleled.”

Beginning in the 1990s, Moss led the MADIT (Multicenter Automatic Defibrillator Implantation Trial) series of clinical trials, which showed that the implantable cardioverter defibrillator or ICD – a device that detects arrhythmias and shocks the heart back into a normal rhythm – significantly reduces the risk of sudden death in patients who’ve experienced a heart attack. In the early 2000s these findings changed medical guidelines worldwide and led to the use of life-saving ICD therapy in hundreds of thousands of patients.

Later, in 2009, Moss completed the MADIT-CRT trial, which found that cardiac resynchronization therapy plus defibrillator – CRT-D therapy – prevents the progression of heart failure in patients living with mild forms of the disease. The device, which improves the mechanical pumping action of the heart and corrects fatal rhythms, was originally approved to treat patients with severe heart failure. Moss’ work opened the door for multitudes more patients to benefit and live longer, better lives.

“Arthur’s research was so successful and powerful because the results of his studies were usually strikingly positive or negative. This came from his rare ability to ask a simple question, and use a simple clinical trial design,” said Bradford C. Berk, M.D., Ph.D., professor of Medicine and Cardiology at URMC. “He did this so well because he was a superb clinician who had a remarkable insight into the underlying pathologic mechanisms of heart disease.”

Colleagues also credit Moss’ research success to his unique ability to bring people together, trigger discussion, and make all involved – from the highest-ranking physician to the newest graduate student or fellow – feel welcome and valued.

“I first met Art in 1976 and was at least three academic ranks lower than anyone else at the meeting,” said Henry (Hank) Greenberg, M.D., special lecturer of Epidemiology and Medicine at the Columbia University Medical Center. “Art sensed this and stated that everyone at the table contributed. This carried forward for four decades and was a reason why his trials were always superbly done. His ego did not get in the way.”

Moss was founding director of URMCs Heart Research Follow-up Program, a worldwide hub of international studies on medical interventions for sudden death, cardiac arrhythmias, heart attack and heart failure. He published more than 750 scientific papers, including a 1962 article – his first of many in the New England Journal of Medicine – highlighting the first three published cases of cardiopulmonary resuscitation (CPR), which included external chest massage followed by external defibrillation.

Charles J. Lowenstein, M.D., chief of Cardiology at URMC, said, “Arthur’s contributions to cardiac electrophysiology were vast and he was extremely well respected as a clinician and researcher. He also trained hundreds of medical students, residents, and fellows, and inspired many of us to dedicate our lives to medicine. This is his greatest legacy.”

Moss attended Yale as an undergraduate then Harvard Medical School. He interned at Massachusetts General Hospital and finished his residency in Rochester, where he also did a fellowship in cardiology. Moss joined the faculty at URMC in 1966 and stayed for the rest of his career, ultimately becoming  the Bradford C. Berk, M.D., Ph.D. Distinguished Professor in Cardiology. A valued member of the faculty, Moss received the Eastman Medal in 2012, the University of Rochester’s highest honor that recognizes individuals who, through their outstanding achievement and dedicated service, embody the high ideals for which the University stands.

On numerous other occasions, Moss was recognized locally, nationally and internationally for his tenacity and advancement of medical and cardiologic science. In 2008 he received the Glorney-Raisbeck Award in Cardiology, the highest honor of the New York Academy of Medicine. A year later he was awarded the prestigious Golden Lionel Award at the Venice International Cardiac Arrhythmias Meeting. The Heart Rhythm Society, the major international electrophysiology society, bestowed its top honor, the Distinguished Scientist Award, to Moss in 2011 and its Pioneer in Cardiac Pacing and EP Award to Moss in 2017.  

On November 11, 2017, just four months before his death, Moss was given the 2017 James B. Herrick Award at the American Heart Association’s Scientific Sessions. The award is given annually to a physician whose scientific achievements have contributed profoundly to the advancement and practice of clinical cardiology.

“Arthur’s passing is very sad news for the world of cardiology and clinical trials,” said David Cannom, director of Cardiology at Good Samaritan Hospital in Los Angeles. “There was no one quite like Arthur in terms of intelligence, judgement, leadership skills and thoughtful friendship. Plus good humor. An era is closing and he will be sorely missed.”  Other colleagues from around the world described him as a “true giant” in the field, a “role model,” and a “pioneer.”

Moss’s daughter Deborah, herself a physician, was always inspired by her dad’s curiosity, creativity and perseverance. “He paid close attention to his patients, their stories and their situations, and generated research questions that would make a difference not just for one patient, but for many patients. He was bold, never afraid to try something new, and wouldn’t stop until he solved a problem. Looking back on the entirety of his career, it was really incredible.”

Moss is survived by his wife Joy F. Moss, three children – Katherine M. Lowengrub, M.D., instructor in Psychiatry at the Sackler School of Medicine in Tel Aviv, Israel; Deborah R. Moss, M.D., M.P.H., associate professor of Pediatrics at the University of Pittsburgh Medical Center; and David A. Moss, Ph.D., professor at Harvard Business School – and nine grandchildren and two great-grandchildren. A memorial service will take place at Temple B’rith Kodesh on Elmwood Ave at 11 a.m. on Sunday, February 18. In lieu of flowers, donations may be sent to:

UR Heart Research Follow-Up Program

Alumni & Advancement Center

300 East River Rd. P.O. Box 270032

Rochester, NY 14627

SOURCE

https://www.urmc.rochester.edu/news/story/5273/renowned-cardiologist-arthur-j.-moss-pioneer-of-research-and-treatment-in-sudden-death-passes-away.aspx

His legacy is a career spanning more than 60 years that was marked by major contributions to cardiac electrophysiology, including the first surgical treatment for long QT syndrome and his leadership in the MADIT trials showing that an implantable cardioverter defibrillator could reduce the risk of sudden cardiac death.

Moss started his career in risk stratification studies and evaluating the potential of ventricular arrhythmias, according to longtime colleague Sanjeev Saksena, MD, past president of the North American Society of Pacing and Electrophysiology. Sakesna said that in 1983 Moss published “pivotal studies on risk stratification after myocardial infarction that led to his recognition as a leader in this field and was famously covered by TIME magazine for these contributions.”

Saksena also noted his early support of Michel Mirowski’s concept of an implanted standby defibrillator. This support, Saksena said “made him a lone voice arguing against the medical establishment more than 40 years ago for development of a therapy that is now a cornerstone of cardiovascular medicine.”

Douglas Zipes, MD, Past President, American College of Cardiology: “Wonderful man, scientist. He was the gold standard role model for the clinician investigator: he took care of patients and advanced the science of cardiology. A great loss, but his observations will live on.”

Robert Myerberg, MD, Professor of Medicine, University of Miami: “Art Moss had had an incredibly productive career. His dominant characteristic was a lack of fear of stepping into areas where there were gaps in our knowledge or untested hypotheses, and find a way to get us on to a path that would ultimately answer important and practical questions … His impact will continue to be felt long into the future. And on a personal level, his warmth and collegiality will be missed by his friends and colleagues.”

Bernard Gersh, MD, Professor of Medicine, Mayo Clinic: “Major contributions to our understanding of the long QT syndrome and the PI [principal investigator] of the major trials that established the clinical role of the ICD.”

Richard L. Page, MD, Chair, Department of Medicine, University of Wisconsin, School of Medicine & Public Health: “Arthur Moss was a consummate professional, gentleman, scholar, and physician. He was a role model for me and for a generation of cardiologists.”

Jagmeet P. Singh MD, Roman W. DeSanctis Endowed Chair in Cardiology, Massachusetts General Hospital Heart Center: “A huge loss for our community. He was my mentor.”

SOURCE

Eminent Cardiologist Arthur Moss Dies

Tributes to a giant in electrophysiology

https://www.medpagetoday.com/cardiology/arrhythmias/71227?xid=nl_mpt_cardiodaily_2018-02-20&eun=g99985d0r&utm_source=Sailthru&utm_medium=email&utm_campaign=CDnews_022018&utm_term=AHA%20Cardiovascular%20Daily%20-%20Active%20Users%20180%20days

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Arrhythmias Detection: Speeding Diagnosis and Treatment – New deep learning algorithm can diagnose 14 types of heart rhythm defects by sifting through hours of ECG data generated by some REMOTELY iRhythm’s wearable monitors

Reporter: Aviva Lev-Ari, PhD, RN

 

Long term, the group hopes this algorithm could be a step toward expert-level arrhythmia diagnosis for people who don’t have access to a cardiologist, as in many parts of the developing world and in other rural areas. More immediately, the algorithm could be part of a wearable device that at-risk people keep on at all times that would alert emergency services to potentially deadly heartbeat irregularities as they’re happening.

said Pranav Rajpurkar, a graduate student and co-lead author of the paper. “For example, two forms of the arrhythmia known as second-degree atrioventricular block look very similar, but one requires no treatment while the other requires immediate attention.”

To test accuracy of the algorithm, the researchers gave a group of three expert cardiologists 300 undiagnosed clips and asked them to reach a consensus about any arrhythmias present in the recordings. Working with these annotated clips, the algorithm could then predict how those cardiologists would label every second of other ECGs with which it was presented, in essence, giving a diagnosis.

http://news.stanford.edu/2017/07/06/algorithm-diagnoses-heart-arrhythmias-cardiologist-level-accuracy/

 iRhythm, maker of portable ECG devices

Image Source:

https://www-technologyreview-com.cdn.ampproject.org/c/s/www.technologyreview.com/s/608234/the-machines-are-getting-ready-to-play-doctor/amp/

Cardiologist-Level Arrhythmia Detection with Convolutional Neural Networks

We develop an algorithm which exceeds the performance of board certified cardiologists in detecting a wide range of heart arrhythmias from electrocardiograms recorded with a single-lead wearable monitor. We build a dataset with more than 500 times the number of unique patients than previously studied corpora. On this dataset, we train a 34-layer convolutional neural network which maps a sequence of ECG samples to a sequence of rhythm classes. Committees of board-certified cardiologists annotate a gold standard test set on which we compare the performance of our model to that of 6 other individual cardiologists. We exceed the average cardiologist performance in both recall (sensitivity) and precision (positive predictive value).

Subjects: Computer Vision and Pattern Recognition (cs.CV)
Cite as: arXiv:1707.01836 [cs.CV]
(or arXiv:1707.01836v1 [cs.CV] for this version)

Submission history

From: Awni Hannun [view email]
[v1] Thu, 6 Jul 2017 15:42:46 GMT (852kb,D)

SOURCE

Active Learning Applied to Patient-Adaptive Heartbeat Classification

Part of: Advances in Neural Information Processing Systems 23 (NIPS 2010)

[PDF] [BibTeX] [Supplemental]

Authors

Abstract

While clinicians can accurately identify different types of heartbeats in electrocardiograms (ECGs) from different patients, researchers have had limited success in applying supervised machine learning to the same task. The problem is made challenging by the variety of tasks, inter- and intra-patient differences, an often severe class imbalance, and the high cost of getting cardiologists to label data for individual patients. We address these difficulties using active learning to perform patient-adaptive and task-adaptive heartbeat classification. When tested on a benchmark database of cardiologist annotated ECG recordings, our method had considerably better performance than other recently proposed methods on the two primary classification tasks recommended by the Association for the Advancement of Medical Instrumentation. Additionally, our method required over 90% less patient-specific training data than the methods to which we compared it.

SOURCE

Cardiologist-Level Arrhythmia Detection With Convolutional Neural Networks

Pranav Rajpurkar*, Awni Hannun*, Masoumeh Haghpanahi, Codie Bourn, and Andrew Ng

A collaboration between Stanford University and iRhythm Technologies

https://stanfordmlgroup.github.io/projects/ecg/

JULY 6, 2017

Stanford computer scientists develop an algorithm that diagnoses heart arrhythmias with cardiologist-level accuracy

A new deep learning algorithm can diagnose 14 types of heart rhythm defects, called arrhythmias, better than cardiologists. This could speed diagnosis and improve treatment for people in rural locations.

The Machines Are Getting Ready to Play Doctor

An algorithm that spots heart arrhythmia shows how AI will revolutionize medicine—but patients must trust machines with their lives.

by Will Knight,  July 7, 2017

https://www-technologyreview-com.cdn.ampproject.org/c/s/www.technologyreview.com/s/608234/the-machines-are-getting-ready-to-play-doctor/amp/

The Dark Secret at the Heart of AI

No one really knows how the most advanced algorithms do what they do. That could be a problem.

by Will Knight, April 11, 2017

https://www.technologyreview.com/s/604087/the-dark-secret-at-the-heart-of-ai/

 

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First U.S. TAVR Patients Treated With Temporary Pacing Lead (Tempo Lead)

Reporter: Aviva Lev-Ari, PhD, RN

 

UPDATED on 8/2/2017

Medtronic wins FDA nod, CE Mark for Avalus aortic valve

AUGUST 2, 2017 BY FINK DENSFORD

http://www.massdevice.com/medtronic-wins-fda-nod-ce-mark-avalus-aortic-valve/?utm_source=newsletter-170802&utm_medium=email&utm_campaign=newsletter-170802&spMailingID=11611945&spUserID=MTU0MTAzNDg3OTA5S0&spJobID=1220180538&spReportId=MTIyMDE4MDUzOAS2

 

 

BioTrace Medical, Inc., a venture backed company based in San Carlos, Calif., is dedicated to reinventing temporary pacing to improve patient outcomes and reduce hospital costs.

For more information: www.biotracemedical.com

 

FDA Clears Temporary Pacing Technology for Transcatheter Aortic Valve and EP Procedures

The BioTrace Medical Tempo temporary pacing lead is designed to reduce complications and hospital length of stay

The Tempo Lead represents the first major advance in temporary pacing since the technology was introduced decades ago,” said Susheel Kodali, M.D., director of the Heart Valve Program at the Center for Interventional Vascular Therapy at Columbia University Medical Center in New York. “As a critical component of every TAVR procedure, temporary leads are integral to successful clinical outcomes for patients. I am excited about the potential of this technology and look forward to using it in my practice.”

Results of the first-in-human study of the technology will be presented at the annual Transcatheter Cardiac Therapeutics (TCT) conference in Washington, D.C. on Sunday, Oct. 30, at 10:59 a.m. eastern time in Room 209, Level 2.

“FDA clearance is an exciting milestone for BioTrace,” said Laura Dietch, CEO of BioTrace Medical. “We are pleased to bring this important innovation to the significant and growing number of patients needing better temporary pacing options to minimize risks and life-threatening complications. We look forward to launching in select U.S. centers in the coming weeks.”

For more information: www.biotracemedical.com

SOURCE

http://www.dicardiology.com/product/fda-clears-temporary-pacing-technology-transcatheter-aortic-valve-and-ep-procedures

December 19, 2016 — BioTrace Medical Inc. announced the first commercial use of the company’s Tempo Temporary Pacing Lead since U.S. Food and Drug Administration (FDA) 510(k) clearance in October.

The first cases involved patients undergoing transcatheter aortic valve replacement (TAVR) procedures and were performed by James Harkness, M.D., interventional cardiologist, and Brian K. Whisenant, M.D., medical director of the Structural Heart Disease Program at Intermountain Medical Center in Salt Lake City, Utah, and Susheel Kodali, M.D., director of the Heart Valve Program at Columbia University Medical Center/New York Presbyterian Hospital.

BioTrace Medical’s Tempo Lead is for use in procedures in which

  • Temporary pacing is indicated, including
  • TAVR and
  • Electrophysiology (EP) procedures.

The lead is designed for secure and stable cardiac pacing with the goal of reducing complications and allowing patients to ambulate sooner after procedures.

“The Tempo Lead is designed to alleviate the risks associated with lead dislodgement and inconsistent pacing, providing a safer option for patients.”

Temporary leads are used in more than 350,000 procedures each year, a number that is growing rapidly as the population ages and TAVR becomes increasingly common. The temporary pacing lead, a small catheter with two electrodes, is placed in the right ventricle of the heart through a vein in the groin or neck. The lead is then connected to an external pacemaker allowing a physician to monitor and control a patient’s heart rate for several days.

SOURCE

http://www.dicardiology.com/content/first-us-tavr-patients-treated-temporary-pacing-lead?eid=333021707&bid=1620839

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The presence of any Valvular Heart Disease (VHD) did not influence the comparison of Dabigatran [Pradaxa, Boehringer Ingelheim] with Warfarin

Reporter: Aviva Lev-Ari, PhD, RN

 

UPDATED on 10/22/2018

Dabigatran (Pradaxa) was no better than aspirin for prevention of recurrent stroke among patients with an embolic stroke of undetermined source in the RE-SPECT ESUS trial reported at the World Stroke Congress.

 

Pradaxa® (dabigatran etexilate)
Clinical experience of Pradaxa® equates to over 9 million patient-years in all licensed indications worldwide. Pradaxa® has been in the market for more than ten years and is approved in over 100 countries.15
Currently approved indications for Pradaxa® are:16,17
  • Prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation and a risk factor for stroke
  • Primary prevention of venous thromboembolic events in patients undergoing elective total hip replacement surgery or total knee replacement surgery
  • Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) and the prevention of recurrent DVT and recurrent PE in adults
Dabigatran, a direct thrombin inhibitor (DTI), was the first widely approved drug in a new generation of direct oral anticoagulants, available to target a high unmet medical need in the prevention and treatment of acute and chronic thromboembolic diseases.18,19,20
REFERENCES

SOURCE

https://www.boehringer-ingelheim.com/press-release/Results-from-two-Pradaxa-trials-to-be-presented-at-WSC

 

 

Event Rate and Outcome Risk, With vs Without Valvular Heart Disease

Outcome Valvular heart disease, event rate/y, % No valvular heart disease, event rate/y, % HR (95% CI)* P
Stroke, systemic embolic event 1.61 1.41 1.09 (0.88–1.33) 0.43
Major bleeding 4.36 2.84 1.32 (1.16–1.33) <0.001
Intracranial hemorrhage 0.51 0.41 1.20 (0.83–1.74) 0.32
All-cause mortality 4.45 3.67 1.09 (0.96–1.23) 0.18
*Adjusted using propensity scores

ORIGINAL RESEARCH ARTICLE

Comparison of Dabigatran versus Warfarin in Patients with Atrial Fibrillation and Valvular Heart Disease: The RE-LY Trial

Michael D. Ezekowitz, Rangadham Nagarakanti, Herbert Noack, Martina Brueckmann, Claire Litherland, Mark Jacobs, Andreas Clemens,Paul A. Reilly, Stuart J. Connolly, Salim Yusuf and Lars Wallentin

 http://dx.doi.org/10.1161/CIRCULATIONAHA.115.020950

 

Results—There were 3950 patients with any VHD:

  • 3101 had mitral regurgitation,
  • 1179 tricuspid regurgitation,
  • 817 aortic regurgitations,
  • 471 aortic stenosis and
  • 193 mild mitral stenosis.

At baseline patients with any VHD had more

  • heart failure,
  • coronary disease,
  • renal impairment and
  • persistent atrial fibrillation.

Patients with any VHD had higher rates of

  • major bleeds (HR 1.32; 95% CI 1.16-1.5)

but similar

  • stroke or systemic embolism (SEE) rates (HR 1.09; 95% CI 0.88-1.33).

For D110 patients, major bleed rates were lower than warfarin (HR 0.73; 95% CI 0.56-0.95 with and HR 0.84; 95% CI 0.71-0.99 without VHD) and

For D150 similar to warfarin in patients with (HR 0.82; 95% CI 0.64-1.06) or without VHD (HR 0.98; 95% CI 0.83-1.15).

For D150 patients stroke/SEE rates were lower versus warfarin with (HR 0.59; 95% CI 0.37-0.93) and without VHD (HR 0.67; 95% CI 0.52-0.86) and similar to warfarin for D110 irrespective of presence of VHD (HR 0.97 CI 0.65-1.45 and 0.85 CI 0.70-1.10).

For intracranial bleeds and death rates for D150 and D110 were lower vs warfarin independent of presence of VHD.

Conclusions—The presence of any VHD did not influence the comparison of dabigatran with warfarin.

Clinical Trial Registration—URL: http://clinicaltrials.gov. Unique Identifier: NCT00262600.

SOURCES

http://circ.ahajournals.org/content/early/2016/08/05/CIRCULATIONAHA.115.020950

http://www.medscape.com/viewarticle/867482?nlid=108872_3866&src=WNL_mdplsfeat_160816_mscpedit_card&uac=93761AJ&spon=2&impID=1179558&faf=1

 

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Familial transthyretin amyloid polyneuropathy

Curator: Larry H. Bernstein, MD, FCAP

LPBI

 

First-Ever Evidence that Patisiran Reduces Pathogenic, Misfolded TTR Monomers and Oligomers in FAP Patients

We reported data from our ongoing Phase 2 open-label extension (OLE) study of patisiran, an investigational RNAi therapeutic targeting transthyretin (TTR) for the treatment of TTR-mediated amyloidosis (ATTR amyloidosis) patients with familial amyloidotic polyneuropathy (FAP). Alnylam scientists and collaborators from The Scripps Research Institute and Misfolding Diagnostics, Inc. were able to measure the effects of patisiran on pathogenic, misfolded TTR monomers and oligomers in FAP patients. Results showed a rapid and sustained reduction in serum non-native conformations of TTR (NNTTR) of approximately 90%. Since NNTTR is pathogenic in ATTR amyloidosis and the level of NNTTR reduction correlated with total TTR knockdown, these results provide direct mechanistic evidence supporting the therapeutic hypothesis that TTR knockdown has the potential to result in clinical benefit. Furthermore, complete 12-month data from all 27 patients that enrolled in the patisiran Phase 2 OLE study showed sustained mean maximum reductions in total serum TTR of 91% for over 18 months and a mean 3.1-point decrease in mNIS+7 at 12 months, which compares favorably to an estimated increase in mNIS+7 of 13 to 18 points at 12 months based upon analysis of historical data sets in untreated FAP patients with similar baseline characteristics. Importantly, patisiran administration continues to be generally well tolerated out to 21 months of treatment.

Read our press release

View the non-native TTR poster (480 KB PDF)

View the complete 12-month patisiran Phase 2 OLE data presentation (620 KB PDF)

We are encouraged by these new data that provide continued support for our hypothesis that patisiran has the potential to halt neuropathy progression in patients with FAP. If these results are replicated in a randomized, double-blind, placebo-controlled study, we believe that patisiran could emerge as an important treatment option for patients suffering from this debilitating, progressive and life-threatening disease.

 

Hereditary ATTR Amyloidosis with Polyneuropathy (hATTR-PN)

ATTR amyloidosis is a progressive, life-threatening disease caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in multiple organs, but primarily in the peripheral nerves and heart. ATTR amyloidosis can lead to significant morbidity, disability, and mortality. The TTR protein is produced primarily in the liver and is normally a carrier for retinol binding protein – one of the vehicles used to transport vitamin A around the body.  Mutations in the TTR gene cause misfolding of the protein and the formation of amyloid fibrils that typically contain both mutant and wild-type TTR that deposit in tissues such as the peripheral nerves and heart, resulting in intractable peripheral sensory neuropathy, autonomic neuropathy, and/or cardiomyopathy.

Click to Enlarge

 

ATTR represents a major unmet medical need with significant morbidity and mortality. There are over 100 reported TTR mutations; the particular TTR mutation and the site of amyloid deposition determine the clinical manifestations of the disease whether it is predominantly symptoms of neuropathy or cardiomyopathy.

Specifically, hereditary ATTR amyloidosis with polyneuropathy (hATTR-PN), also known as familial amyloidotic polyneuropathy (FAP), is an inherited, progressive disease leading to death within 5 to 15 years. It is due to a mutation in the transthyretin (TTR) gene, which causes misfolded TTR proteins to accumulate as amyloid fibrils predominantly in peripheral nerves and other organs. hATTR-PN can cause sensory, motor, and autonomic dysfunction, resulting in significant disability and death.

It is estimated that hATTR-PN, also known as FAP, affects approximately 10,000 people worldwide.  Patients have a life expectancy of 5 to 15 years from symptom onset, and the only treatment options for early stage disease are liver transplantation and TTR stabilizers such as tafamidis (approved in Europe) and diflunisal.  Unfortunately liver transplantation has limitations, including limited organ availability as well as substantial morbidity and mortality. Furthermore, transplantation eliminates the production of mutant TTR but does not affect wild-type TTR, which can further deposit after transplantation, leading to cardiomyopathy and worsening of neuropathy. There is a significant need for novel therapeutics to treat patients who have inherited mutations in the TTR gene.

Our ATTR program is the lead effort in our Genetic Medicine Strategic Therapeutic Area (STAr) product development and commercialization strategy, which is focused on advancing innovative RNAi therapeutics toward genetically defined targets for the treatment of rare diseases with high unmet medical need.  We are developing patisiran (ALN-TTR02), an intravenously administered RNAi therapeutic, to treat the hATTR-PN form of the disease.

Patisiran for the Treatment hATTR-PN

APOLLO Phase 3 Trial

In 2012, Alnylam entered into an exclusive alliance with Genzyme, a Sanofi company, to develop and commercialize RNAi therapeutics, including patisiran and revusiran, for the treatment of ATTR amyloidosis in Japan and the broader Asian-Pacific region. In early 2014, this relationship was extended as a significantly broader alliance to advance RNAi therapeutics as genetic medicines. Under this new agreement, Alnylam will lead development and commercialization of patisiran in North America and Europe while Genzyme will develop and commercialize the product in the rest of world.

 

Hereditary ATTR Amyloidosis with Cardiomyopathy (hATTR-CM)

ATTR amyloidosis is a progressive, life-threatening disease caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in multiple organs, but primarily in the peripheral nerves and heart. ATTR amyloidosis can lead to significant morbidity, disability, and mortality. The TTR protein is produced primarily in the liver and is normally a carrier for retinol binding protein – one of the vehicles used to transport vitamin A around the body.  Mutations in the TTR gene cause misfolding of the protein and the formation of amyloid fibrils that typically contain both mutant and wild-type TTR that deposit in tissues such as the peripheral nerves and heart, resulting in intractable peripheral sensory neuropathy, autonomic neuropathy, and/or cardiomyopathy.

Click to Enlarge                            http://www.alnylam.com/web/assets/tetramer.jpg

ATTR represents a major unmet medical need with significant morbidity and mortality. There are over 100 reported TTR mutations; the particular TTR mutation and the site of amyloid deposition determine the clinical manifestations of the disease, whether it is predominantly symptoms of neuropathy or cardiomyopathy.

Specifically, hereditary ATTR amyloidosis with cardiomyopathy (hATTR-CM), also known as familial amyloidotic cardiomyopathy (FAC), is an inherited, progressive disease leading to death within 2 to 5 years. It is due to a mutation in the transthyretin (TTR) gene, which causes misfolded TTR proteins to accumulate as amyloid fibrils primarily in the heart. Hereditary ATTR amyloidosis with cardiomyopathy can result in heart failure and death.

While the exact numbers are not known, it is estimated hATTR-CM, also known as FAC affects at least 40,000 people worldwide.  hATTR-CM is fatal within 2 to 5 years of diagnosis and treatment is currently limited to supportive care.  Wild-type ATTR amyloidosis (wtATTR amyloidosis), also known as senile systemic amyloidosis, is a nonhereditary, progressive disease leading to death within 2 to 5 years. It is caused by misfolded transthyretin (TTR) proteins that accumulate as amyloid fibrils in the heart. Wild-type ATTR amyloidosis can cause cardiomyopathy and result in heart failure and death. There are no approved therapies for the treatment of hATTR-CM or SSA; hence there is a significant unmet need for novel therapeutics to treat these patients.

Our ATTR program is the lead effort in our Genetic Medicine Strategic Therapeutic Area (STAr) product development and commercialization strategy, which is focused on advancing innovative RNAi therapeutics toward genetically defined targets for the treatment of rare diseases with high unmet medical need.  We are developing revusiran (ALN-TTRsc), a subcutaneously administered RNAi therapeutic for the treatment of hATTR-CM.

Revusiran for the Treatment of hATTR-CM

ENDEAVOUR Phase 3 Trial

In 2012, Alnylam entered into an exclusive alliance with Genzyme, a Sanofi company, to develop and commercialize RNAi therapeutics, including patisiran and revusiran, for the treatment of ATTR amyloidosis in Japan and the broader Asian-Pacific region. In early 2014, this relationship was extended as a broader alliance to advance RNAi therapeutics as genetic medicines. Under this new agreement, Alnylam and Genzyme have agreed to co-develop and co-commercialize revusiran in North America and Europe, with Genzyme developing and commercializing the product in the rest of world. This broadened relationship on revusiran is aimed at expanding and accelerating the product’s global value.

Pre-Clinical Data and Advancement of ALN-TTRsc02 for Transthyretin-Mediated Amyloidosis

We presented pre-clinical data with ALN-TTRsc02, an investigational RNAi therapeutic targeting transthyretin (TTR) for the treatment of TTR-mediated amyloidosis (ATTR amyloidosis).  In pre-clinical studies, including those in non-human primates (NHPs), ALN-TTRsc02 achieved potent and highly durable knockdown of serum TTR of up to 99% with multi-month durability achieved after just a single dose, supportive of a potentially once quarterly dose regimen. Results from studies comparing TTR knockdown activity of ALN-TTRsc02 to that of revusiran showed that ALN-TTRsc02 has a markedly superior TTR knockdown profile.  Further, in initial rat toxicology studies, ALN-TTRsc02 was found to be generally well tolerated with no significant adverse events at doses as high as 100 mg/kg.

Read our press release

View the presentation

http://www.alnylam.com/product-pipeline/hereditary-attr-amyloidosis-with-cardiomyopathy/

 

Emerging Therapies for Transthyretin Cardiac Amyloidosis Could Herald a New Era for the Treatment of HFPEF

Oct 14, 2015   |  Adam Castano, MDDavid Narotsky, MDMathew S. Maurer, MD, FACC

http://www.acc.org/latest-in-cardiology/articles/2015/10/13/08/35/emerging-therapies-for-transthyretin-cardiac-amyloidosis#sthash.9xzc0rIe.dpuf

Heart failure with a preserved ejection fraction (HFPEF) is a clinical syndrome that has no pharmacologic therapies approved for this use to date. In light of failed medicines, cardiologists have refocused treatment strategies based on the theory that HFPEF is a heterogeneous clinical syndrome with different etiologies. Classification of HFPEF according to etiologic subtype may, therefore, identify cohorts with treatable pathophysiologic mechanisms and may ultimately pave the way forward for developing meaningful HFPEF therapies.1

A wealth of data now indicates that amyloid infiltration is an important mechanism underlying HFPEF. Inherited mutations in transthyretin cardiac amyloidosis (ATTRm) or the aging process in wild-type disease (ATTRwt) cause destabilization of the transthyretin (TTR) protein into monomers or oligomers, which aggregate into amyloid fibrils. These insoluble fibrils accumulate in the myocardium and result in diastolic dysfunction, restrictive cardiomyopathy, and eventual congestive heart failure (Figure 1). In an autopsy study of HFPEF patients, almost 20% without antemortem suspicion of amyloid had left ventricular (LV) TTR amyloid deposition.2 Even more resounding evidence for the contribution of TTR amyloid to HFPEF was a study in which 120 hospitalized HFPEF patients with LV wall thickness ≥12 mm underwent technetium-99m 3,3-diphosphono-1,2-propranodicarboxylic acid (99mTc-DPD) cardiac imaging,3,4 a bone isotope known to have high sensitivity and specificity for diagnosing TTR cardiac amyloidosis.5,6 Moderate-to-severe myocardial uptake indicative of TTR cardiac amyloid deposition was detected in 13.3% of HFPEF patients who did not have TTR gene mutations. Therefore, TTR cardiac amyloid deposition, especially in older adults, is not rare, can be easily identified, and may contribute to the underlying pathophysiology of HFPEF.

Figure 1

As no U.S. Food and Drug Administration-approved drugs are currently available for the treatment of HFPEF or TTR cardiac amyloidosis, the development of medications that attenuate or prevent TTR-mediated organ toxicity has emerged as an important therapeutic goal. Over the past decade, a host of therapies and therapeutic drug classes have emerged in clinical trials (Table 1), and these may herald a new direction for treating HFPEF secondary to TTR amyloid.

Table 1

TTR Silencers (siRNA and Antisense Oligonucleotides)

siRNA

Ribonucleic acid interference (RNAi) has surfaced as an endogenous cellular mechanism for controlling gene expression. Small interfering RNAs (siRNAs) delivered into cells can disrupt the production of target proteins.7,8 A formulation of lipid nanoparticle and triantennary N-acetylgalactosamine (GalNAc) conjugate that delivers siRNAs to hepatocytes is currently in clinical trials.9 Prior research demonstrated these GalNAc-siRNA conjugates result in robust and durable knockdown of a variety of hepatocyte targets across multiple species and appear to be well suited for suppression of TTR gene expression and subsequent TTR protein production.

The TTR siRNA conjugated to GalNAc, ALN-TTRSc, is now under active investigation as a subcutaneous injection in phase 3 clinical trials in patients with TTR cardiac amyloidosis.10 Prior phase 2 results demonstrated that ALN-TTRSc was generally well tolerated in patients with significant TTR disease burden and that it reduced both wild-type and mutant TTR gene expression by a mean of 87%. Harnessing RNAi technology appears to hold great promise for treating patients with TTR cardiac amyloidosis. The ability of ALN-TTRSc to lower both wild-type and mutant proteins may provide a major advantage over liver transplantation, which affects the production of only mutant protein and is further limited by donor shortage, cost, and need for immunosuppression.

Antisense Oligonucleotides

Antisense oligonucleotides (ASOs) are under clinical investigation for their ability to inhibit hepatic expression of amyloidogenic TTR protein. Currently, the ASO compound, ISIS-TTRRx, is under investigation in a phase 3 multicenter, randomized, double-blind, placebo-controlled clinical trial in patients with familial amyloid polyneuropathy (FAP).11 The primary objective is to evaluate its efficacy as measured by change in neuropathy from baseline relative to placebo. Secondary measures will evaluate quality of life (QOL), modified body mass index (mBMI) by albumin, and pharmacodynamic effects on retinol binding protein. Exploratory objectives in a subset of patients with LV wall thickness ≥13 mm without a history of persistent hypertension will examine echocardiographic parameters, N-terminal pro–B-type natriuretic peptide (NT-proBNP), and polyneuropathy disability score relative to placebo. These data will facilitate analysis of the effect of antisense oligonucleotide-mediated TTR suppression on the TTR cardiac phenotype with a phase 3 trial anticipated to begin enrollment in 2016.

TTR Stabilizers (Diflunisal, Tafamidis)

Diflunisal

Several TTR-stabilizing agents are in various stages of clinical trials. Diflunisal, a traditionally used and generically available nonsteroidal anti-inflammatory drug (NSAID), binds and stabilizes familial TTR variants against acid-mediated fibril formation in vitro and is now in human clinical trials.12,13 The use of diflunisal in patients with TTR cardiac amyloidosis is controversial given complication of chronic inhibition of cyclooxygenase (COX) enzymes, including gastrointestinal bleeding, renal dysfunction, fluid retention, and hypertension that may precipitate or exacerbate heart failure in vulnerable individuals.14-17 In TTR cardiac amyloidosis, an open-label cohort study suggested that low-dose diflunisal with careful monitoring along with a prophylactic proton pump inhibitor could be safely administered to compensated patients.18 An association was observed, however, between chronic diflunisal use and adverse changes in renal function suggesting that advanced kidney disease may be prohibitive in diflunisal therapy.In FAP patients with peripheral or autonomic neuropathy randomized to diflunisal or placebo, diflunisal slowed progression of neurologic impairment and preserved QOL over two years of follow-up.19 Echocardiography demonstrated cardiac involvement in approximately 50% of patients.20 Longer-term safety and efficacy data over an average 38 ± 31 months in 40 Japanese patients with hereditary ATTR amyloidosis who were not candidates for liver transplantation showed that diflunisal was mostly well tolerated.12 The authors cautioned the need for attentive monitoring of renal function and blood cell counts. Larger multicenter collaborations are needed to determine diflunisal’s true efficacy in HFPEF patients with TTR cardiac amyloidosis.

Tafamidis

Tafamidis is under active investigation as a novel compound that binds to the thyroxine-binding sites of the TTR tetramer, inhibiting its dissociation into monomers and blocking the rate-limiting step in the TTR amyloidogenesis cascade.21 The TTR compound was shown in an 18-month double-blind, placebo-controlled trial to slow progression of neurologic symptoms in patients with early-stage ATTRm due to the V30M mutation.22 When focusing on cardiomyopathy in a phase 2, open-label trial, tafamidis also appeared to effectively stabilize TTR tetramers in non-V30M variants, wild-type and V122I, as well as biochemical and echocardiographic parameters.23,24 Preliminary data suggests that clinically stabilized patients had shorter disease duration, lower cardiac biomarkers, less myocardial thickening, and higher EF than those who were not stabilized, suggesting early institution of therapy may be beneficial. A phase 3 trial has completed enrollment and will evaluate the efficacy, safety, and tolerability of tafamidis 20 or 80 mg orally vs. placebo.25 This will contribute to long-term safety and efficacy data needed to determine the therapeutic effects of tafamidis among ATTRm variants.

Amyloid Degraders (Doxycycline/TUDCA and Anti-SAP Antibodies)

Doxycycline/TUDCA

While silencer and stabilizer drugs are aimed at lowering amyloidogenic precursor protein production, they cannot remove already deposited fibrils in an infiltrated heart. Removal of already deposited fibrils by amyloid degraders would be an important therapeutic strategy, particularly in older adults with heavily infiltrated hearts reflected by thick walls, HFPEF, systolic heart failure, and restrictive cardiomyopathy. Combined doxycycline and tauroursodeoxycholic acid (TUDCA) disrupt TTR amyloid fibrils and appeared to have an acceptable safety profile in a small phase 2 open-label study among 20 TTR patients. No serious adverse reactions or clinical progression of cardiac or neuropathic involvement was observed over one year.26 An active phase 2, single-center, open-label, 12-month study will assess primary outcome measures including mBMI, neurologic impairment score, and NT-proBNP.27 Another phase 2 study is examining the tolerability and efficacy of doxycycline/TUDCA over an 18-month period in patients with TTR amyloid cardiomyopathy.28 Additionally, a study in patients with TTR amyloidosis is ongoing to determine the effect of doxycycline alone on neurologic function, cardiac biomarkers, echocardiographic parameters, modified body mass index, and autonomic neuropathy.29

Anti-SAP Antibodies

In order to safely clear established amyloid deposits, the role of the normal, nonfibrillar plasma glycoprotein present in all human amyloid deposits, serum amyloid P component (SAP), needs to be more clearly understood.30 In mice with amyloid AA type deposits, administration of antihuman SAP antibody triggered a potent giant cell reaction that removed massive visceral amyloid deposits without adverse effects.31 In humans with TTR cardiac amyloidosis, anti-SAP antibody treatments could be feasible because the bis-D proline compound, CPHPC, is capable of clearing circulating human SAP, which allow anti-SAP antibodies to reach residual deposited SAP. In a small, open-label, single-dose-escalation, phase 1 trial involving 15 patients with systemic amyloidosis, none of whom had clinical evidence of cardiac amyloidosis, were treated with CPHPC followed by human monoclonal IgG1 anti-SAP antibody.32 No serious adverse events were reported and amyloid deposits were cleared from the liver, kidney, and lymph node. Anti-SAP antibodies hold promise as a potential amyloid therapy because of their potential to target all forms of amyloid deposits across multiple tissue types.

Mutant or wild-type TTR cardiac amyloidoses are increasingly recognized as a cause of HFPEF. Clinicians need to be aware of this important HFPEF etiology because the diverse array of emerging disease-modifying agents for TTR cardiac amyloidosis in human clinical trials has the potential to herald a new era for the treatment of HFPEF.

References

  1. Maurer MS, Mancini D. HFpEF: is splitting into distinct phenotypes by comorbidities the pathway forward? J Am Coll Cardiol 2014;64:550-2.
  2. Mohammed SF, Mirzoyev SA, Edwards WD, et al. Left ventricular amyloid deposition in patients with heart failure and preserved ejection fraction. JACC Heart Fail 2014;2:113-22.
  3. González-López E, Gallego-Delgado M, Guzzo-Merello G, et al. Wild-type transthyretin amyloidosis as a cause of heart failure with preserved ejection fraction. Eur Heart J 2015.
  4. Castano A, Bokhari S, Maurer MS. Unveiling wild-type transthyretin cardiac amyloidosis as a significant and potentially modifiable cause of heart failure with preserved ejection fraction. Eur Heart J 2015 Jul 28. [Epub ahead of print]
  5. Rapezzi C, Merlini G, Quarta CC, et al. Systemic cardiac amyloidoses: disease profiles and clinical courses of the 3 main types. Circulation 2009;120:1203-12.
  6. Bokhari S, Castano A, Pozniakoff T, Deslisle S, Latif F, Maurer MS. (99m)Tc-pyrophosphate scintigraphy for differentiating light-chain cardiac amyloidosis from the transthyretin-related familial and senile cardiac amyloidoses. Circ Cardiovasc Imaging 2013;6:195-201.
  7. Fire A, Xu S, Montgomery MK, Kostas SA, Driver SE, Mello CC. Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature 1998;391:806-11.
  8. Elbashir SM, Harborth J, Lendeckel W, Yalcin A, Weber K, Tuschl T. Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature 2001;411:494-8.
  9. Kanasty R, Dorkin JR, Vegas A, Anderson D. Delivery materials for siRNA therapeutics. Nature Mater 2013;12:967-77.
  10. U.S. National Institutes of Health. Phase 2 Study to Evaluate ALN-TTRSC in Patients With Transthyretin (TTR) Cardiac Amyloidosis (ClinicalTrials.gov website). 2014. Available at: https://www.clinicaltrials.gov/ct2/show/NCT01981837. Accessed 8/19/2015.
  11. U.S. National Institutes of Health. Efficacy and Safety of ISIS-TTRRx in Familial Amyloid Polyneuropathy (Clinical Trials.gov Website. 2013. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01737398. Accessed 8/19/2015.
  12. Sekijima Y, Dendle MA, Kelly JW. Orally administered diflunisal stabilizes transthyretin against dissociation required for amyloidogenesis. Amyloid 2006;13:236-49.
  13. Tojo K, Sekijima Y, Kelly JW, Ikeda S. Diflunisal stabilizes familial amyloid polyneuropathy-associated transthyretin variant tetramers in serum against dissociation required for amyloidogenesis. Neurosci Res 2006;56:441-9.
  14. Epstein M. Non-steroidal anti-inflammatory drugs and the continuum of renal dysfunction. J Hypertens Suppl 2002;20:S17-23.
  15. Wallace JL. Pathogenesis of NSAID-induced gastroduodenal mucosal injury. Best Pract Res Clin Gastroenterol 2001;15:691-703.
  16. Mukherjee D, Nissen SE, Topol EJ. Risk of cardiovascular events associated with selective COX-2 inhibitors. JAMA 2001;286:954-9.
  17. Page J, Henry D. Consumption of NSAIDs and the development of congestive heart failure in elderly patients: an underrecognized public health problem. Arch Intern Med 2000;160:777-84.
  18. Castano A, Helmke S, Alvarez J, Delisle S, Maurer MS. Diflunisal for ATTR cardiac amyloidosis. Congest Heart Fail 2012;18:315-9.
  19. Berk JL, Suhr OB, Obici L, et al. Repurposing diflunisal for familial amyloid polyneuropathy: a randomized clinical trial. JAMA 2013;310:2658-67.
  20. Quarta CCF, Solomon RH Suhr SD, et al. The prevalence of cardiac amyloidosis in familial amyloidotic polyneuropathy with predominant neuropathy: The Diflunisal Trial. International Symposium on Amyloidosis 2014:88-9.
  21. Hammarstrom P, Jiang X, Hurshman AR, Powers ET, Kelly JW. Sequence-dependent denaturation energetics: A major determinant in amyloid disease diversity. Proc Natl Acad Sci U S A 2002;99 Suppl 4:16427-32.
  22. Coelho T, Maia LF, Martins da Silva A, et al. Tafamidis for transthyretin familial amyloid polyneuropathy: a randomized, controlled trial. Neurology 2012;79:785-92.
  23. Merlini G, Plante-Bordeneuve V, Judge DP, et al. Effects of tafamidis on transthyretin stabilization and clinical outcomes in patients with non-Val30Met transthyretin amyloidosis. J Cardiovasc Transl Res 2013;6:1011-20.
  24. Maurer MS, Grogan DR, Judge DP, et al. Tafamidis in transthyretin amyloid cardiomyopathy: effects on transthyretin stabilization and clinical outcomes. Circ Heart Fail 2015;8:519-26.
  25. U.S. National Institutes of Health. Safety and Efficacy of Tafamidis in Patients With Transthyretin Cardiomyopathy (ATTR-ACT) (ClinicalTrials.gov website). 2014. Available at: http://www.clinicaltrials.gov/show/NCT01994889. Accessed 8/19/2015.
  26. Obici L, Cortese A, Lozza A, et al. Doxycycline plus tauroursodeoxycholic acid for transthyretin amyloidosis: a phase II study. Amyloid 2012;19 Suppl 1:34-6.
  27. U.S. National Institutes of Health. Safety, Efficacy and Pharmacokinetics of Doxycycline Plus Tauroursodeoxycholic Acid in Transthyretin Amyloidosis (ClinicalTrials.gov website). 2011. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01171859. Accessed 8/19/2015.
  28. U.S. National Institutes of Health. Tolerability and Efficacy of a Combination of Doxycycline and TUDCA in Patients With Transthyretin Amyloid Cardiomyopathy (ClinicalTrials.gov website). 2013. Available at: http://www.clinicaltrials.gov/ct2/show/NCT01855360. Accessed 8/19/2015.
  29. U.S. National Institutes of Health. Safety and Effect of Doxycycline in Patients With Amyloidosis (ClinicalTrials.gov website).2015. Available at: https://clinicaltrials.gov/ct2/show/NCT01677286. Accessed 8/19/2015.
  30. Pepys MB, Dash AC. Isolation of amyloid P component (protein AP) from normal serum as a calcium-dependent binding protein. Lancet 1977;1:1029-31.
  31. Bodin K, Ellmerich S, Kahan MC, et al. Antibodies to human serum amyloid P component eliminate visceral amyloid deposits. Nature 2010;468:93-7.
  32. Richards DB, Cookson LM, Berges AC, et al. Therapeutic Clearance of Amyloid by Antibodies to Serum Amyloid P Component. N Engl J Med 2015;373:1106-14.

 

The Acid-Mediated Denaturation Pathway of Transthyretin Yields a Conformational Intermediate That Can Self-Assemble into Amyloid

Zhihong Lai , Wilfredo Colón , and Jeffery W. Kelly *
Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255
Biochemistry199635 (20), pp 6470–6482   http://dx.doi.org:/10.1021/bi952501g
Publication Date (Web): May 21, 1996  Copyright © 1996 American Chemical Society

Transthyretin (TTR) amyloid fibril formation is observed during partial acid denaturation and while refolding acid-denatured TTR, implying that amyloid fibril formation results from the self-assembly of a conformational intermediate. The acid denaturation pathway of TTR has been studied in detail herein employing a variety of biophysical methods to characterize the intermediate(s) capable of amyloid fibril formation. At physiological concentrations, tetrameric TTR remains associated from pH 7 to pH 5 and is incapable of amyloid fibril formation. Tetrameric TTR dissociates to a monomer in a process that is dependent on both pH and protein concentration below pH 5. The extent of amyloid fibril formation correlates with the concentration of the TTR monomer having an altered, but defined, tertiary structure over the pH range of 5.0−3.9. The inherent Trp fluorescence-monitored denaturation curve of TTR exhibits a plateau over the pH range where amyloid fibril formation is observed (albeit at a higher concentration), implying that a steady-state concentration of the amyloidogenic intermediate with an altered tertiary structure is being detected. Interestingly, 1-anilino-8-naphthalenesulfonate fluorescence is at a minimum at the pH associated with maximal amyloid fibril formation (pH 4.4), implying that the amyloidogenic intermediate does not have a high extent of hydrophobic surface area exposed, consistent with a defined tertiary structure. Transthyretin has two Trp residues in its primary structure, Trp-41 and Trp-79, which are conveniently located far apart in the tertiary structure of TTR. Replacement of each Trp with Phe affords two single Trp containing variants which were used to probe local pH-dependent tertiary structural changes proximal to these chromophores. The pH-dependent fluorescence behavior of the Trp-79-Phe mutant strongly suggests that Trp-41 is located near the site of the tertiary structural rearrangement that occurs in the formation of the monomeric amyloidogenic intermediate, likely involving the C-strand−loop−D-strand region. Upon further acidification of TTR (below pH 4.4), the structurally defined monomeric amyloidogenic intermediate begins to adopt alternative conformations that are not amyloidogenic, ultimately forming an A-state conformation below pH 3 which is also not amyloidogenic. In summary, analytical equilibrium ultracentrifugation, SDS−PAGE, far- and near-UV CD, fluorescence, and light scattering studies suggest that the amyloidogenic intermediate is a monomeric predominantly β-sheet structure having a well-defined tertiary structure.

 

Prevention of Transthyretin Amyloid Disease by Changing Protein Misfolding Energetics

Per Hammarström*, R. Luke Wiseman*, Evan T. Powers, Jeffery W. Kelly   + Author Affiliations

Science  31 Jan 2003; 299(5607):713-716   http://dx.doi.org:/10.1126/science.1079589

Genetic evidence suggests that inhibition of amyloid fibril formation by small molecules should be effective against amyloid diseases. Known amyloid inhibitors appear to function by shifting the aggregation equilibrium away from the amyloid state. Here, we describe a series of transthyretin amyloidosis inhibitors that functioned by increasing the kinetic barrier associated with misfolding, preventing amyloidogenesis by stabilizing the native state. The trans-suppressor mutation, threonine 119 → methionine 119, which is known to ameliorate familial amyloid disease, also functioned through kinetic stabilization, implying that this small-molecule strategy should be effective in treating amyloid diseases.

 

Rational design of potent human transthyretin amyloid disease inhibitors

Thomas Klabunde1,2, H. Michael Petrassi3, Vibha B. Oza3, Prakash Raman3, Jeffery W. Kelly3 & James C. Sacchettini1

Nature Structural & Molecular Biology 2000; 7: 312 – 321.                http://dx.doi.org:/10.1038/74082

The human amyloid disorders, familial amyloid polyneuropathy, familial amyloid cardiomyopathy and senile systemic amyloidosis, are caused by insoluble transthyretin (TTR) fibrils, which deposit in the peripheral nerves and heart tissue. Several nonsteroidal anti-inflammatory drugs and structurally similar compounds have been found to strongly inhibit the formation of TTR amyloid fibrils in vitro. These include flufenamic acid, diclofenac, flurbiprofen, and resveratrol. Crystal structures of the protein–drug complexes have been determined to allow detailed analyses of the protein–drug interactions that stabilize the native tetrameric conformation of TTR and inhibit the formation of amyloidogenic TTR. Using a structure-based drug design approach ortho-trifluormethylphenyl anthranilic acid and N-(meta-trifluoromethylphenyl) phenoxazine 4,6-dicarboxylic acid have been discovered to be very potent and specific TTR fibril formation inhibitors. This research provides a rationale for a chemotherapeutic approach for the treatment of TTR-associated amyloid diseases.

 

First European consensus for diagnosis, management, and treatment of transthyretin familial amyloid polyneuropathy

Adams, Davida; Suhr, Ole B.b; Hund, Ernstc; Obici, Laurad; Tournev, Ivailoe,f; Campistol, Josep M.g; Slama, Michel S.h; Hazenberg, Bouke P.i; Coelho, Teresaj; from the European Network for TTR-FAP (ATTReuNET)

Current Opin Neurol: Feb 2016; 29 – Issue – p S14–S26      http://dx.doi.org:/10.1097/WCO.0000000000000289

Purpose of review: Early and accurate diagnosis of transthyretin familial amyloid polyneuropathy (TTR-FAP) represents one of the major challenges faced by physicians when caring for patients with idiopathic progressive neuropathy. There is little consensus in diagnostic and management approaches across Europe.

Recent findings: The low prevalence of TTR-FAP across Europe and the high variation in both genotype and phenotypic expression of the disease means that recognizing symptoms can be difficult outside of a specialized diagnostic environment. The resulting delay in diagnosis and the possibility of misdiagnosis can misguide clinical decision-making and negatively impact subsequent treatment approaches and outcomes.

Summary: This review summarizes the findings from two meetings of the European Network for TTR-FAP (ATTReuNET). This is an emerging group comprising representatives from 10 European countries with expertise in the diagnosis and management of TTR-FAP, including nine National Reference Centres. The current review presents management strategies and a consensus on the gold standard for diagnosis of TTR-FAP as well as a structured approach to ongoing multidisciplinary care for the patient. Greater communication, not just between members of an individual patient’s treatment team, but also between regional and national centres of expertise, is the key to the effective management of TTR-FAP.

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Transthyretin familial amyloid polyneuropathy (TTR-FAP) is a highly debilitating and irreversible neurological disorder presenting symptoms of progressive sensorimotor and autonomic neuropathy [1▪,2▪,3]. TTR-FAP is caused by misfolding of the transthyretin (TTR) protein leading to protein aggregation and the formation of amyloid fibrils and, ultimately, to amyloidosis (commonly in the peripheral and autonomic nervous system and the heart) [4,5]. TTR-FAP usually proves fatal within 7–12 years from the onset of symptoms, most often due to cardiac dysfunction, infection, or cachexia [6,7▪▪].

The prevalence and disease presentation of TTR-FAP vary widely within Europe. In endemic regions (northern Portugal, Sweden, Cyprus, and Majorca), patients tend to present with a distinct genotype in large concentrations, predominantly a Val30Met substitution in the TTR gene [8–10]. In other areas of Europe, the genetic footprint of TTR-FAP is more varied, with less typical phenotypic expression [6,11]. For these sporadic or scattered cases, a lack of awareness among physicians of variable clinical features and limited access to diagnostic tools (i.e., pathological studies and genetic screening) can contribute to high rates of misdiagnosis and poorer patient outcomes [1▪,11]. In general, early and late-onset variants of TTR-FAP, found within endemic and nonendemic regions, present several additional diagnostic challenges [11,12,13▪,14].

Delay in the time to diagnosis is a major obstacle to the optimal management of TTR-FAP. With the exception of those with a clearly diagnosed familial history of FAP, patients still invariably wait several years between the emergence of first clinical signs and accurate diagnosis [6,11,14]. The timely initiation of appropriate treatment is particularly pertinent, given the rapidity and irreversibility with which TTR-FAP can progress if left unchecked, as well as the limited effectiveness of available treatments during the later stages of the disease [14]. This review aims to consolidate the existing literature and present an update of the best practices in the management of TTR-FAP in Europe. A summary of the methods used to achieve a TTR-FAP diagnosis is presented, as well as a review of available treatments and recommendations for treatment according to disease status.

Patients with TTR-FAP can present with a range of symptoms [11], and care should be taken to acquire a thorough clinical history of the patient as well as a family history of genetic disease. Delay in diagnosis is most pronounced in areas where TTR-FAP is not endemic or when there is no positive family history [1▪]. TTR-FAP and TTR-familial amyloid cardiomyopathy (TTR-FAC) are the two prototypic clinical disease manifestations of a broader disease spectrum caused by an underlying hereditary ATTR amyloidosis [19]. In TTR-FAP, the disease manifestation of neuropathy is most prominent and definitive for diagnosis, whereas cardiomyopathy often suggests TTR-FAC. However, this distinction is often superficial because cardiomyopathy, autonomic neuropathy, vitreous opacities, kidney disease, and meningeal involvement all may be present with varying severity for each patient with TTR-FAP.

Among early onset TTR-FAP with usually positive family history, symptoms of polyneuropathy present early in the disease process and usually predominate throughout the progression of the disease, making neurological testing an important diagnostic aid [14]. Careful clinical examination (e.g., electromyography with nerve conduction studies and sympathetic skin response, quantitative sensation test, quantitative autonomic test) can be used to detect, characterize, and scale the severity of neuropathic abnormalities involving small and large nerve fibres [10]. Although a patient cannot be diagnosed definitively with TTR-FAP on the basis of clinical presentation alone, symptoms suggesting the early signs of peripheral neuropathy, autonomic dysfunction, and cardiac conduction disorders or infiltrative cardiomyopathy are all indicators that further TTR-FAP diagnostic investigation is warranted. Late-onset TTR-FAP often presents as sporadic cases with distinct clinical features (e.g., milder autonomic dysfunction) and can be more difficult to diagnose than early-onset TTR-FAP (Table 2) [1▪,11,12,13▪,14,20].

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Genetic testing is carried out to allow detection of specific amyloidogenic TTR mutations (Table 1), using varied techniques depending on the expertise and facilities available in each country (Table S2, http://links.lww.com/CONR/A39). A targeted approach to detect a specific mutation can be used for cases belonging to families with previous diagnosis. In index cases of either endemic and nonendemic regions that do not have a family history of disease, are difficult to confirm, and have atypical symptoms, TTR gene sequencing is required for the detection of both predicted and new amyloidogenic mutations [26,27].

Following diagnosis, the neuropathy stage and systemic extension of the disease should be determined in order to guide the next course of treatment (Table 4) [3,30,31]. The three stages of TTR-FAP severity are graded according to a patient’s walking disability and degree of assistance required [30]. Systemic assessment, especially of the heart, eyes, and kidney, is also essential to ensure all aspects of potential impact of the disease can be detected [10].

Table 4

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The goals of cardiac investigations are to detect serious conduction disorders with the risk of sudden death and infiltrative cardiomyopathy. Electrocardiograms (ECG), Holter-ECG, and intracardiac electrophysiology study are helpful to detect conduction disorders. Echocardiograms, cardiac magnetic resonance imaging, scintigraphy with bone tracers, and biomarkers (e.g., brain natriuretic peptide, troponin) can all help to diagnose infiltrative cardiomyopathy[10]. An early detection of cardiac abnormalities has obvious benefits to the patient, given that the prophylactic implantation of pacemakers was found to prevent 25% of major cardiac events in TTR-FAP patients followed up over an average of 4 years [32▪▪]. Assessment of cardiac denervation with 123-iodine meta-iodobenzylguanidine is a powerful prognostic marker in patients diagnosed with FAP [33].

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Tafamidis

Tafamidis is a first-in-class therapy that slows the progression of TTR amyloidogenesis by stabilizing the mutant TTR tetramer, thereby preventing its dissociation into monomers and amyloidogenic and toxic intermediates [55,56]. Tafamidis is currently indicated in Europe for the treatment of TTR amyloidosis in adult patients with stage I symptomatic polyneuropathy to delay peripheral neurological impairment [57].

In an 18-month, double-blind, placebo-controlled study of patients with early-onset Val30Met TTR-FAP, tafamidis was associated with a 52% lower reduction in neurological deterioration (P = 0.027), a preservation of nerve function, and TTR stabilization versus placebo [58▪▪]. However, only numerical differences were found for the coprimary endpoints of neuropathy impairment [neuropathy impairment score in the lower limb (NIS-LL) responder rates of 45.3% tafamidis vs 29.5% placebo; P = 0.068] and quality of life scores [58▪▪]. A 12-month, open-label extension study showed that the reduced rates of neurological deterioration associated with tafamidis were sustained over 30 months, with earlier initiation of tafamidis linking to better patient outcomes (P = 0.0435) [59▪]. The disease-slowing effects of tafamidis may be dependent on the early initiation of treatment. In an open-label study with Val30Met TTR-FAP patients with late-onset and advanced disease (NIS-LL score >10, mean age 56.4 years), NIS-LL and disability scores showed disease progression despite 12 months of treatment with tafamidis, marked by a worsening of neuropathy stage in 20% and the onset of orthostatic hypotension in 22% of patients at follow-up [60▪].

Tafamidis is not only effective in patients exhibiting the Val30Met mutation; it also has proven efficacy, in terms of TTR stabilization, in non-Val30Met patients over 12 months [61]. Although tafamidis has demonstrated safe use in patients with TTR-FAP, care should be exercised when prescribing to those with existing digestive problems (e.g., diarrhoea, faecal incontinence) [60▪].

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Diflunisal

Diflunisal is a nonsteroidal anti-inflammatory drug (NSAID) that, similar to tafamidis, slows the rate of amyloidogenesis by preventing the dissociation, misfolding, and misassembly of the mutated TTR tetramer [62,63]. Off-label use has been reported for patients with stage I and II disease, although diflunisal is not currently licensed for the treatment of TTR-FAP.

Evidence for the clinical effectiveness of diflunisal in TTR-FAP derives from a placebo-controlled, double-blind, 24-month study in 130 patients with clinically detectable peripheral or autonomic neuropathy[64▪]. The deterioration in NIS scores was significantly more pronounced in patients receiving placebo compared with those taking diflunisal (P = 0.001), and physical quality of life measures showed significant improvement among diflunisal-treated patients (P = 0.001). Notable during this study was the high rate of attrition in the placebo group, with 50% more placebo-treated patients dropping out of this 2-year study as a result of disease progression, advanced stage of the disease, and varied mutations.

One retrospective analysis of off-label use of diflunisal in patients with TTR-FAP reported treatment discontinuation in 57% of patients because of adverse events that were largely gastrointestinal [65]. Conclusions on the safety of diflunisal in TTR-FAP will depend on further investigations on the impact of known cardiovascular and renal side-effects associated with the NSAID drug class [66,67].

 

 

 

 

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