Schomburg John L, Medina Eduardo M, Lahti Matthew T, Bianco Richard W
Department of Surgery, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
J Invest Surg. 2012 Jun;25(3):150-5. doi: 10.3109/08941939.2011.616256.
Mechanical heart valve replacement is an absolute indication for anticoagulation. We report our experience comparing dabigatran to warfarin as thromboembolic prophylaxis after mechanical mitral valve replacement in the swine model.
Nineteen swine underwent mitral valve replacement with a regulatory approved, 27 mm mechanical valve. Two control groups consisted of three animals receiving no anticoagulation and five animals receiving warfarin (5 mg once a day [QD], adjusted to maintain international normalized ratio [INR] from 2.0 to 2.5). The experimental group consisted of 11 animals receiving dabigatran (20 mg/kg twice a day [BID]). The study period was 90 days. The primary outcome was animal mortality; secondary outcomes included presence of thrombus and bleeding complications.
The experimental group had four full-term survivors (40.0%); there were no full-term survivors in either control group. The average length of survival was 50.3 days in the experimental group compared with 18.7 and 15.6 days for the no anticoagulation and warfarin groups, respectively (p = .017). Valve thrombus was observed in all study groups. Hemorrhagic complications were present in 40% of the warfarin group and 27% of the dabigatran group.
There was a significant mortality benefit to the use of dabigatran as thromboembolic prophylaxis when compared with warfarin in the setting of mechanical heart valve replacement in the swine model. There was also a decreased incidence of bleeding complications in the dabigatran group compared with the warfarin group. Valve thrombus was observed in all study groups. Any conclusions regarding the rate of thrombus formation are outside the scope of this study and merit further investigation.
机械心脏瓣膜置换术是抗凝治疗的绝对指征。我们报告在猪模型中比较达比加群与华法林用于机械二尖瓣置换术后血栓栓塞预防的经验。
19头猪接受了经监管部门批准的27毫米机械瓣膜二尖瓣置换术。两个对照组，一组3只动物不接受抗凝治疗，另一组5只动物接受华法林治疗（每日一次5毫克，调整剂量以维持国际标准化比值[INR]在2.0至2.5之间）。实验组由11只接受达比加群治疗的动物组成（每日两次，每次20毫克/千克）。研究期为90天。主要结局是动物死亡率；次要结局包括血栓形成和出血并发症。
实验组有4只足月存活动物（40.0%）；两个对照组均无足月存活动物。实验组的平均存活时间为50.3天，而不抗凝组和华法林组分别为18.7天和15.6天（p = 0.017）。所有研究组均观察到瓣膜血栓形成。华法林组40%出现出血并发症，达比加群组27%出现出血并发症。
在猪模型的机械心脏瓣膜置换术中，与华法林相比，使用达比加群进行血栓栓塞预防有显著的死亡率获益。与华法林组相比，达比加群组的出血并发症发生率也有所降低。所有研究组均观察到瓣膜血栓形成。关于血栓形成率的任何结论超出了本研究范围，值得进一步研究。
