The off-label use of dabigatran (Pradaxa) in patients with mechanical heart valves may be problematic, according to two case reports in the Journal of the American College of Cardiology.
In both instances, the patients had been switched from warfarin to dabigatran, which is approved for reducing stroke risk in nonvalvular atrial fibrillation.
The patients, two women in their 50s, became symptomatic within a month of switching to dabigatran. One woman was on warfarin for 8 years after receiving an aortic valve replacement. The other woman was on warfarin for about 5 years for a prosthetic mitral valve, reported Joel Price, MD, MPH, and colleagues from the University of Ottawa Heart Institute in Ontario, in a research correspondence.
The patients were compliant with warfarin and with dabigatran, and neither experienced valve thrombus or bleeding while on warfarin.
"I would not use factor IIa or Xa inhibitors in place of warfarin in patients with a mechanical valve requiring anticoagulation except in the context of a clinical trial or for compassionate use indications," Gordon Tomaselli, MD, director of cardiology at Johns Hopkins School of Medicine in Baltimore, told MedPage Today.
Boehringer Ingelheim, dabigatran's manufacturer, last year launched the phase II RE-ALIGN trial, which is testing three doses of the drug in patients with mechanical valves.
POSTED BY: Steven Almany M.D.