Meurin Philippe, Tabet Jean Yves, Weber Hélène, Renaud Nathalie, Ben Driss Ahmed
Les Grands Prés, Villeneuve Saint Denis, France.
Circulation. 2006 Jan 31;113(4):564-9. doi: 10.1161/CIRCULATIONAHA.105.575571.
After mechanical heart valve replacement (MHVR), long-term use of unfractionated heparin is sometimes required because vitamin K antagonists (VKA) are temporarily contraindicated or because the time to reach the target international normalized ratio is long. The aim of this study was to investigate the feasibility of low-molecular-weight heparin treatment in these patients.
This work was conducted as a prospective study. We selected all patients (n=695) who underwent MHVR and were transferred to a postoperative cardiac rehabilitation center between January 2000 and January 2005. The study focused on patients who had not yet started VKA therapy or who had a below-target international normalized ratio despite VKA therapy. Unfractionated heparin was replaced by enoxaparin (100 IU/kg BID) until VKA treatment was fully effective. Two hundred fifty patients (60+/-11 years old) were enrolled 16+/-11 days after surgery (aortic valve replacement, n=190; mitral valve replacement, n=34; double valve replacement, n=26). Of these, 50% had permanent or transient atrial fibrillation, 40% had hypertension, 13% had diabetes, and 19% had a history of cardiac surgery. The mean duration of low-molecular-weight heparin treatment was 8.3+/-6.0 days. Patients were followed for 90 days, during which there were two major and three minor bleeding episodes and one transient ischemic attack. There were no cases of valve thrombosis and no deaths.
After MHVR, one third of patients leave the cardiac surgery unit before VKA treatment is fully effective. Bridging anticoagulation therapy with enoxaparin appears to be feasible during this high-risk period for thromboembolism and could shorten the length of hospital stay.
在机械心脏瓣膜置换术（MHVR）后，有时需要长期使用普通肝素，原因是维生素K拮抗剂（VKA）暂时禁忌使用，或者达到目标国际标准化比值的时间较长。本研究的目的是探讨在这些患者中使用低分子肝素治疗的可行性。
本研究为前瞻性研究。我们选取了2000年1月至2005年1月期间接受MHVR并转入术后心脏康复中心的所有患者（n = 695）。该研究聚焦于尚未开始VKA治疗或尽管接受VKA治疗但国际标准化比值仍未达标的患者。在VKA治疗完全起效前，用依诺肝素（100 IU/kg，每日两次）替代普通肝素。250例患者（年龄60±11岁）在术后16±11天入组（主动脉瓣置换术，n = 190；二尖瓣置换术，n = 34；双瓣膜置换术，n = 26）。其中，50%有永久性或短暂性心房颤动，40%有高血压，13%有糖尿病，19%有心脏手术史。低分子肝素治疗的平均持续时间为8.3±6.0天。对患者进行了90天的随访，在此期间发生了2次大出血和3次小出血事件以及1次短暂性脑缺血发作。没有瓣膜血栓形成病例且无死亡病例。
在MHVR后，三分之一的患者在VKA治疗完全起效前就离开了心脏外科病房。在这个血栓栓塞的高危期，用依诺肝素进行桥接抗凝治疗似乎是可行的，并且可以缩短住院时间。
