Presentation at 93rd AATS Annual Meeting Describes Preliminary Results
Newswise — Minneapolis, MN, May 6, 2013 – For more than 40 years, patients under 65 years of age requiring heart valve replacement have had to choose between a mechanical valve that offers life-long durability but requires aggressive warfarin anticoagulation or a biological (cow or pig) valve that will wear out in 10-20 years but does not require anticoagulation. Aggressive warfarin anticoagulation is accompanied by significant annual risk of bleeding, while inadequate anticoagulation of a mechanical artificial valve has been associated with high risk of clotting problems that can cause strokes.
A newer generation mechanical heart valve, manufactured by On-X Life Technologies, Austin, TX, has several design features that make it more efficient and less likely to clot. The FDA is allowing a randomized trial to be conducted to determine whether it is safe and effective to treat patients with an On-X mechanical aortic valve with less aggressive anticoagulation than has previously been recommended by the American Heart Association and American College of Cardiology.
In an interim report to be presented at the 93rd AATS Annual Meeting in Minneapolis on May 6, 2013, John D. Puskas, MD, Professor and Associate Chief of the Division of Cardiothoracic Surgery, Emory University School of Medicine, Athens, GA, and his co-investigators show that lower dose anticoagulation therapy, combined with low-dose aspirin, resulted in a reduction of 55 to 60% of the incidence of adverse bleeding events without significant increases in stroke, transient ischemic attack or total neurological events when used in conjunction with On-X mechanical aortic valve.
As part of the Prospective Randomized On-X Anticoagulation Clinical Trial (PROACT), a control group of patients received standard treatment of warfarin administered to maintain a target range of the International Normalized Ratio (INR) of 2.0-3.0. The second treatment group received low-dose warfarin, targeting an INR of 1.5-2.0.
From June 2006 until October 2009, 375 Aortic Valve Replacement (AVR) patients were randomized into control (190) and treatment (185) groups three months after surgery. All patients had received standard therapy for the first 3 months including aspirin 81 mg daily. Mean age was 55.8 years in the control group and 54.1 years in the treatment group. Approximately 80% of the patients were male and 93% were in sinus rhythm before valve replacement. Patients were followed for an average of 3.82 years.
Dr. Puskas concludes that “Anticoagulation may be safely reduced in AVR patients after implantation of this approved bileaflet mechanical prosthesis. In combination with low-dose aspirin, this therapy resulted in significantly lower risk of bleeding than customary aggressive anticoagulation, without significant increase in clots or strokes.”
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NOTES FOR EDITORS“Reduced Anticoagulation after Mechanical Aortic Valve Replacement: Interim Results from the PROACT Randomized FDA IDE Trial,” by John Puskas, Dennis Nichols, Marc Gerdisch, Reed Quinn, Charles Anderson, Birger Rhenman, Lilibeth Fermin, Michael McGrath, Bobby Kong, Chad Hughes, Gulshan Sethi, Michael Wait, Tomas Martin, and Allen Graeve. Presentation at the 93rd AATS Annual Meeting. May 4-8, 2013. Minneapolis, MN, during the Plenary Scientific Session on May 6, 7:45 AM CT. http://aats.org/annualmeeting/
For more information contact Nicole Baritot, Associate Managing Editor, AATS Scientific Publications, at +1 978-299-4520 or [email protected]. Journalists wishing to interview Dr. Puskas should contact Janet Christenbury, Director of Media Relations, EHC, at 404-727-8599 or [email protected].
ABOUT THE AUTHORSJohn Puskas, MD, Emory University, Atlanta, GADennis Nichols, MD, Emory University, Atlanta, GAAllen Graeve, MD, Emory University, Atlanta, GACharles Anderson, MD, Tacoma General Hospital, Tacoma, WAMarc Gerdisch, MD, St. Francis Heart Center, Indianapolis, INReed Quinn, MD, Maine Medical Center, Portland, MELilibeth Fermin, MD, Maine Medical Center, Portland, MEBirger Rhenman, MD, Southern Arizona VA Medical Center, Tucson, AZMichael McGrath, MD, Sentara Norfolk General Hospital, Norfolk, VABobby Kong, MD, St. Joseph Mercy Hospital, Ypsilanti, MIChad Hughes, MD, Duke University Medical Center, Durham, NCGulshan Sethi, MD, University of Arizona, Tucson, AZMichael Wait, MD, UT Southwestern Medical Center, Dallas, TXTomas Martin, MD, University of Florida, Gainesville, FL
ABOUT THE AMERICAN ASSOCIATION FOR THORACIC SURGERY (AATS)The American Association for Thoracic Surgery (AATS) is an international organization of over 1,300 of the world’s foremost thoracic and cardiothoracic surgeons, representing 35 countries. AATS encourages and stimulates education and investigation into the areas of intrathoracic physiology, pathology and therapy. Founded in 1917 by a respected group of the last century’s earliest pioneers in the field of thoracic surgery, the AATS’ original mission was to “foster the evolution of an interest in surgery of the Thorax.” One hundred years later, the AATS continues to be the premiere association among cardiothoracic surgeons. The purpose of the Association is the continual enhancement of the ability of cardiothoracic surgeons to provide the highest level of quality patient care. To this end, the AATS encourages, promotes, and stimulates the scientific investigation and study of cardiothoracic surgery. Visit www.aats.org.
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