von Schacky C
Medizinische Klinik Klinikum Innenstadt der Universität München.
Z Kardiol. 1998;87 Suppl 4:46-55.
After implantation of a mechanical cardiac valve, lifelong, full anticoagulation has been the tradition. After implantation of a biological valve, anticoagulation during 3 months subsequent to the operation is customary. This review evaluates the role of platelet inhibition after cardiac valve replacement. Platelet aggregation is inhibited effectively by aspirin in a daily dose of 100-160 mg. At this dose, episodes of severe bleeding are not significantly more frequent than during placebo, whereas patients on full anticoagulation bleed at a rate of 2% per year. After implantation of a mechanical cardiac valve, sole platelet inhibition is inferior to full anticoagulation. With a lower rate of bleeding, aspirin appears to prevent thromboembolic episodes caused by mechanical bileaflet prostheses (e.g., St. Jude) in the aortic position, and is almost as efficient as full anticoagulation. In Germany, patients with a porcine bioprosthesis, as currently in use, in the aortic position, frequently receive 100 mg aspiring per day. For patients with porcine bioprostheses in the mitral plus eventually in the aortic position in stable sinus rhythm, 100 mg aspirin per day is preferred to anticoagulation. For children with mechanical aortic valves, aspirin (2 mg/kg/day) needs to be considered an effective and convenient alternative to anticoagulation. Combining anticoagulation with 100 mg aspirin per day after implantation of a left-sided mechanical cardiac valve is pathophysiologically sound, but used to be considered as rendering the patients too bleeding-prone. Recently, total mortality and morbidity definitely have been demonstrated to be reduced by combined anticoagulation and platelet inhibition as compared to sole anticoagulation. Combining platelet inhibition with moderate anticoagulation (INR 2.0-3.0) was superior to combining it with full anticoagulation in terms of safety (INR > 3.0). Thus, current evidence favors combining moderate anticoagulation with 100 mg aspirin per day after left-sided mechanical cardiac valve replacement.
植入机械心脏瓣膜后，终身进行充分抗凝一直是惯例。植入生物瓣膜后，术后3个月进行抗凝是常规做法。本综述评估了心脏瓣膜置换术后血小板抑制的作用。每日剂量为100 - 160 mg的阿司匹林可有效抑制血小板聚集。在此剂量下，严重出血事件的发生率并不比服用安慰剂时显著更高，而接受充分抗凝治疗的患者每年出血率为2%。植入机械心脏瓣膜后，单纯的血小板抑制不如充分抗凝。由于出血率较低，阿司匹林似乎可预防主动脉位置的机械双叶瓣膜（如圣犹达瓣膜）引起的血栓栓塞事件，其效果几乎与充分抗凝相同。在德国，目前使用的主动脉位置的猪生物瓣膜患者，经常每日服用100 mg阿司匹林。对于二尖瓣以及最终主动脉位置处于稳定窦性心律的猪生物瓣膜患者，每日服用100 mg阿司匹林优于抗凝治疗。对于患有机械主动脉瓣膜的儿童，阿司匹林（2 mg/kg/天）可被视为抗凝治疗的一种有效且便捷的替代方法。在植入左侧机械心脏瓣膜后，将抗凝与每日100 mg阿司匹林联合使用在病理生理学上是合理的，但过去曾被认为会使患者出血倾向过高。最近，与单纯抗凝相比，联合抗凝和血小板抑制已被明确证明可降低总死亡率和发病率。在安全性方面（国际标准化比值[INR] > 3.0），将血小板抑制与中度抗凝（INR 2.0 - 3.0）联合使用优于与充分抗凝联合使用。因此，目前的证据支持在左侧机械心脏瓣膜置换术后将中度抗凝与每日100 mg阿司匹林联合使用。
