September 2012 JACC
Doctors switching their patients with prosthetic heart valves from warfarin to the new oral anticoagulants could put them at risk.
The complaint comes from Canadian authors, with a letter published recently on Journal of the American College of Cardiology which describes the cases of two women who had undergone valve replacement a few years earlier and were treated with warfarin, who, after the replacement of the 'old' anticoagulant with dabigatran, had a valve thrombosis.
"The message is that dabigatran has only been approved for patients who have non-valvular atrial fibrillation and is, instead, starting to use it off-label, but that practice is potentially harmful," said senior study author Munir Boodhwani. , from the University of Ottawa's Heart Institute, to Heartwire. cardiologists” added the specialist.
The author also said that he believes that the new anticoagulants have excellent application potential even in contexts other than the current indication, but underlined the need for dose-finding studies and clinical trials to demonstrate their safety and efficacy in such settings. "Until then, the use of such off-label agents should be avoided," the author recommended. “It is very premature and potentially dangerous. Patients could have a valve thrombosis and die of it without even realizing that this was the problem.”
In a letter to the director, Boodhwani and his collaborators report the cases of two of their patients. The first is that of a 51-year-old woman who had had her aortic valve replaced 8 years earlier and was then placed on warfarin therapy, with no adverse events. Two months before he presented to the cardiologist complaining of progressive exertional dyspnea for about 4 weeks, his primary care physician had switched warfarin to dabigatran (150 mg twice daily).
Ultrasound revealed severe aortic valve stenosis and severe left ventricular dysfunction with a probable mass on the graft. The patient was rushed to the Ottawa Heart Institute with cardiogenic shock and rushed to the operating room, where she experienced cardiac arrest.
A transesophageal ultrasound (TEE) followed by surgical exploration confirmed the presence of multiple masses on the prosthetic aortic valve, which was replaced without complications. While undergoing bypass, the woman underwent dialysis to reduce circulating levels of dabigatran, but nevertheless had extensive coagulopathy. Fortunately, his postoperative course was uneventful, with a complete recovery of the organ.
The second case is that of a 59-year-old woman who had her mitral valve replaced in 2007 due to rheumatic disease and who presented for routine follow-up. Over
