Orlando， FL – 在第58届ACC年会i2峰会上提交了一项新的研究，这项研究表明我们可以通过一种以最小的侵入技术植入心脏的器械来预防非瓣膜性房颤引起的卒中，这项技术有可能代替广泛的药物治疗。

    在房颤患者的血栓保护试验（PROTECT AF）中，研究者比较了目前应用华法林抗凝的治疗，以及一种名为WATCHMAN的左心耳封闭系统（可防止左心耳内血栓的可膨胀镍钛装置）的治疗效果。研究者发现，WATCHMAN可降低30%的心血管原因死亡和卒中的联合风险的发生（包括栓塞引起的确血和脑出血）。

    来自梅奥医学研究院的David R. Holmes， Jr教授提到：“由于房颤患者卒中的风险增加了6倍，故需要长期抗凝治疗。这项装置远期效果非常好，既能有效预防缺血性脑卒中，又可以消除华法林治疗相关的出血性脑卒中和出血事件。”
房颤是临床常见的心律失常事件。在心脏搏动时，由于心房的颤动而不能将血液挤入心室，导致心房内血液淤积凝结。华法林的抗凝治疗是被证明预防房颤患者发生血栓性卒中的有效措施，但由于其在某些病人中可引起严重的出血事件而应谨慎应用。此外，应用华法林期间还应监测血液指标并限制患者活动。

    WATCHMAN装置通过下肢静脉导管置入心脏。导管先到达右房，再经房间隔穿刺后进入左房，到达左心耳开口后立即释放WATCHMAN，可防止血栓形成和脱落。

    PROTECT AF 研究是随机、前瞻性研究，如选了707例非瓣膜性房颤患者，463例应接受WATCHMAN置入后而终止华法林治疗，244例患者长期接受华法林治疗，随访确血性和出血性卒中相关事件及心血管原因死亡的联合发生率以作为主要评估终点，器械组对华法林组为3.4%：5.0%，风险降低了32%。

    就这项装置的安全性来说，研究者观察了患者在器械置入过程的相关并发症，大部分并发症的发生都与装置置入过程有关。然而，一旦成功置入WATCHMAN装置并终止华法林治疗后，并发症的发生率明显下降。
最后，研究者总结道：WATCHMAN装置是可替代华法林预防房颤患者发生卒中的有效措施。

（陈维君  吕树铮  首都医科大学附属北京安贞医院）

 英文原文：

The WATCHMAN May Offer Alternative to Blood-Thinning Medications

Orlando， FL – A device implanted in the heart using minimally invasive techniques may replace the most widely prescribed drug for stroke prevention in patients with nonvalvular atrial fibrillation， according to research presented during the i2 Summit at the American College of Cardiology’s 58th annual scientific session.

In the Embolic Protection in Patients with Atrial Fibrillation (PROTECT AF) trial， researchers compared the current standard of therapy， anticoagulation with warfarin， to a fabric-covered expandable nitinol cage known as the WATCHMAN， which blocks blood clots that typically form in the left atrial appendage (LAA)， an outpouching of the left atrium. They found that the WATCHMAN reduced by some 30 percent the combined risk of cardiovascular death and stroke (both ischemic – the type caused by a blood clot – and hemorrhagic – the type caused by excessive bleeding into the brain).

“Patients with atrial fibrillation have a six-fold increased risk of stroke and therefore require long-term anticoagulation therapy，” said David R. Holmes， Jr.， M.D.， Scripps Professor of Medicine at the Mayo Graduate School of Medicine， Rochester， MN. “The placement of this device results in excellent long-term outcomes – effective ischemic stroke prevention with the elimination of hemorrhagic strokes and major bleeding often associated with the use of warfarin.”
Atrial fibrillation is a common heart rhythm disorder that causes the upper chamber of the heart to quiver rather than squeeze blood out with each beat. When blood is allowed to pool in the atrium， it can form clots. Anticoagulation with warfarin has been proven effective for the prevention of clot-related strokes in atrial fibrillation but it is used conservatively， largely because it can cause serious bleeding in some patients. It also necessitates regular blood tests and may require that patients restrict certain physical activities.

To implant the WATCHMAN， an interventional cardiologist guides the device into the heart through a catheter inserted in a vein in the upper leg. The catheter is threaded first into the right atrium， then into the left atrium through a puncture in the wall separating the two upper chambers of the heart. Once the catheter is positioned in the opening of LAA， the WATCHMAN is released and left permanently in place to block the formation and release of blood clots.

For the PROTECT AF study， 707 patients with nonvalvular atrial fibrillation were randomly assigned to closure of the LAA with the WATCHMAN device (463 patients)， followed by discontinuation of warfarin， or to long-term treatment with warfarin (244 patients). The study follow-up that the combined rate of stroke (ischemic and hemorrhagic) and cardiovascular death – the primary measures of effectiveness – was 3.4 per 100 patient-years in the device group vs. 5.0 per 100 patient-years in the warfarin group， a reduction of 32 percent.

As for the safety of the device， the researchers observed more procedure-related complications in patients treated with the device. Most complications were related to device implantation. However， after successful implantation of the WATCHMAN and discontinuation of warfarin therapy， complication rates were significantly lower with device therapy.
The researchers concluded that the WATCHMAN is an effective alternative to warfarin therapy for preventing stroke in patients with atrial fibrillation.