Low-dose anticoagulation therapy used with new design mechanical heart valve lowers bleeding risk

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 with less aggressive anticoagulation than has previously been recommended by the 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 , 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, or total neurological events when used in conjunction with the 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 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."

Provided by American Association for Thoracic Surgery

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Use of drug-eluting stents may cut in-hospital mortality

13 hours ago

(HealthDay)—Use of drug-eluting stents (DES) rather than bare-metal stents (BMS) for percutaneous coronary intervention (PCI) is associated with lower rates of in-hospital mortality, according to research ...

Gel implant might help fight heart failure

13 hours ago

(HealthDay)—Injecting beads of gel into the wall of a still-beating heart has the potential to improve the health of patients with severe heart failure, according to a new study.

Obesity fuels silent heart damage

15 hours ago

Using an ultrasensitive blood test to detect the presence of a protein that heralds heart muscle injury, researchers from Johns Hopkins and elsewhere have found that obese people without overt heart disease ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.