12月19日，美国食品与药物管理局（FDA）发布公告称，机械人工心脏瓣膜置换者不应使用抗凝药达比加群酯甲磺酸盐预防卒中或血栓。同时，FDA还提示尚未评估生物心脏瓣膜置换者应用达比加群酯的安全性，因此也不建议这类患者应用达比加群。

    近期，欧洲RE-ALIGN临床研究部分提前终止，原因是在机械瓣膜置换者中，达比加群应用者的卒中、心脏病发作和血栓形成比华法林应用者更高。同时，前者在行机械瓣膜置换术后出血发生率更高。

    达比加群是用于非瓣膜性房颤患者的抗凝剂，以减少这类患者的卒中和血栓发生，但不适用于瓣膜性房颤患者。

    达比加群酯在欧洲也获准用于非瓣膜性房颤患者的抗凝治疗，还适用于髋关节和膝关节置换术后患者静脉血栓栓塞的预防。

    FDA提醒公众，应用达比加群的任何类型人工瓣膜置换者应尽快和医生取得联系，以确定最合适的抗凝治疗方案。在未获得医学专业医师指导前，患者不可擅自停用抗凝剂或达比加群酯；否则会增加卒中和血栓危险。

    爱爱医评论：达比加群作为多数房颤患者用来防止缺血性脑卒中的抗凝药物，其长期临床治疗数据能够让医生更加放心，但新的研究证实，机械性人工心脏瓣膜置换者不应使用达比加群进行抗凝，否则会增加卒中和血栓危险。因此，达比加群适用于非瓣膜性房颤的抗凝治疗，对生物瓣膜置换者的安全性尚未得到评估，这些患者也不建议使用达比加群。

    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.