12月19日，美國食品與藥物管理局（FDA）發(fā)布公告稱，機械人工心臟瓣膜置換者不應使用抗凝藥達比加群酯甲磺酸鹽預防卒中或血栓。同時，F(xiàn)DA還提示尚未評估生物心臟瓣膜置換者應用達比加群酯的安全性，因此也不建議這類患者應用達比加群。

    近期，歐洲RE-ALIGN臨床研究部分提前終止，原因是在機械瓣膜置換者中，達比加群應用者的卒中、心臟病發(fā)作和血栓形成比華法林應用者更高。同時，前者在行機械瓣膜置換術后出血發(fā)生率更高。

    達比加群是用于非瓣膜性房顫患者的抗凝劑，以減少這類患者的卒中和血栓發(fā)生，但不適用于瓣膜性房顫患者。

    達比加群酯在歐洲也獲準用于非瓣膜性房顫患者的抗凝治療，還適用于髖關節(jié)和膝關節(jié)置換術后患者靜脈血栓栓塞的預防。

    FDA提醒公眾，應用達比加群的任何類型人工瓣膜置換者應盡快和醫(yī)生取得聯(lián)系，以確定最合適的抗凝治療方案。在未獲得醫(yī)學專業(yè)醫(yī)師指導前，患者不可擅自停用抗凝劑或達比加群酯；否則會增加卒中和血栓危險。

    愛愛醫(yī)評論：達比加群作為多數(shù)房顫患者用來防止缺血性腦卒中的抗凝藥物，其長期臨床治療數(shù)據(jù)能夠讓醫(yī)生更加放心，但新的研究證實，機械性人工心臟瓣膜置換者不應使用達比加群進行抗凝，否則會增加卒中和血栓危險。因此，達比加群適用于非瓣膜性房顫的抗凝治療，對生物瓣膜置換者的安全性尚未得到評估，這些患者也不建議使用達比加群。

    附：Pradaxa (dabigatran etexilate mesylate): Drug Safety Communication - Should Not Be Used in Patients with Mechanical Prosthetic Heart Valves

    [Posted 12/19/2012]    AUDIENCE: Cardiology, Patients

    ISSUE: The U.S. Food and Drug Administration (FDA) is informing health care professionals and the public that the blood thinner (anticoagulant) Pradaxa (dabigatran etexilate mesylate) should not be used to prevent stroke or blood clots (major thromboembolic events) in patients with mechanical heart valves, also known as mechanical prosthetic heart valves. A clinical trial in Europe (the RE-ALIGN trial)1 was recently stopped because Pradaxa users were more likely to experience strokes, heart attacks, and blood clots forming on the mechanical heart valves than were users of the anticoagulant warfarin. There was also more bleeding after valve surgery in the Pradaxa users than in the warfarin users.

    Pradaxa is not approved for patients with atrial fibrillation caused by heart valve problems.  FDA is requiring a contraindication (a warning against use) of Pradaxa in patients with mechanical heart valves.

    BACKGROUND:  Pradaxa is a blood-thinning medication used to reduce the risk of stroke and blood clots in patients with a specific condition called non-valvular atrial fibrillation (AF), a common heart rhythm abnormality that causes the upper chambers of the heart, or atria, to beat rapidly and irregularly.  Pradaxa is not indicated for patients with atrial fibrillation caused by heart valve problems.

    RECOMMENDATION: Health care professionals should promptly transition any patient with a mechanical heart valve who is taking Pradaxa to another medication.  The use of Pradaxa in patients with another type of valve replacement made of natural biological tissue, known as a bioprosthetic valves, has not been evaluated and cannot be recommended. Patients with all types of prosthetic heart valve replacements taking Pradaxa should talk to their health care professional as soon as possible to determine the most appropriate anticoagulation treatment.  Patients should not stop taking anticoagulant medications without guidance from their health care professional; stopping Pradaxa or other anticoagulants suddenly can increase the risk of blood clots and stroke.