University of Ottawa Heart Institute, Ottawa, ON, Canada.
N Engl J Med. 2013 May 30;368(22):2084-93. doi: 10.1056/NEJMoa1302946. Epub 2013 May 9.
Many patients requiring pacemaker or implantable cardioverter-defibrillator (ICD) surgery are taking warfarin. For patients at high risk for thromboembolic events, guidelines recommend bridging therapy with heparin; however, case series suggest that it may be safe to perform surgery without interrupting warfarin treatment. There have been few results from clinical trials to support the safety and efficacy of this approach.
We randomly assigned patients with an annual risk of thromboembolic events of 5% or more to continued warfarin treatment or to bridging therapy with heparin. The primary outcome was clinically significant device-pocket hematoma, which was defined as device-pocket hematoma that necessitated prolonged hospitalization, interruption of anticoagulation therapy, or further surgery (e.g., hematoma evacuation).
The data and safety monitoring board recommended termination of the trial after the second prespecified interim analysis. Clinically significant device-pocket hematoma occurred in 12 of 343 patients (3.5%) in the continued-warfarin group, as compared with 54 of 338 (16.0%) in the heparin-bridging group (relative risk, 0.19; 95% confidence interval, 0.10 to 0.36; P<0.001). Major surgical and thromboembolic complications were rare and did not differ significantly between the study groups. They included one episode of cardiac tamponade and one myocardial infarction in the heparin-bridging group and one stroke and one transient ischemic attack in the continued-warfarin group.
As compared with bridging therapy with heparin, a strategy of continued warfarin treatment at the time of pacemaker or ICD surgery markedly reduced the incidence of clinically significant device-pocket hematoma. (Funded by the Canadian Institutes of Health Research and the Ministry of Health and Long-Term Care of Ontario; BRUISE CONTROL ClinicalTrials.gov number, NCT00800137.).
许多需要起搏器或植入式心脏复律除颤器（ICD）手术的患者正在服用华法林。对于血栓栓塞事件风险较高的患者，指南建议用肝素进行桥接治疗；然而，病例系列研究表明，不停用华法林治疗而进行手术可能是安全的。临床试验的结果很少支持这种方法的安全性和有效性。
我们将每年血栓栓塞事件风险为 5%或更高的患者随机分配继续接受华法林治疗或用肝素进行桥接治疗。主要结局是有临床意义的器械袋血肿，定义为需要延长住院时间、中断抗凝治疗或进一步手术（如血肿清除）的器械袋血肿。
数据和安全监测委员会在第二次预定中期分析后建议终止试验。继续华法林组 343 例患者中有 12 例（3.5%）发生有临床意义的器械袋血肿，而肝素桥接组 338 例患者中有 54 例（16.0%）（相对风险，0.19；95%置信区间，0.10 至 0.36；P<0.001）。主要手术和血栓栓塞并发症罕见，两组之间无显著差异。包括肝素桥接组 1 例心脏压塞和 1 例心肌梗死，以及继续华法林组 1 例中风和 1 例短暂性脑缺血发作。
与肝素桥接治疗相比，在起搏器或 ICD 手术时继续华法林治疗的策略显著降低了有临床意义的器械袋血肿的发生率。（由加拿大卫生研究院和安大略省卫生和长期护理部资助；BRUISE CONTROL ClinicalTrials.gov 编号，NCT00800137。）
