Clinical Cardiology, Thrombosis Center, University of Padova School of Medicine, Via Giustiniani 2, 35128 Padova, Italy.
Thromb Haemost. 2010 Feb;103(2):442-9. doi: 10.1160/TH09-05-0311. Epub 2010 Jan 13.
It has been observed that elderly patients with nonvalvular atrial fibrillation (NVAF) benefit from standard [an international normalised ratio (INR) goal of 2.0-3.0] oral anticoagulant treatment (OAT). The hypothesis that lower-intensity anticoagulation therapy can offset the higher bleeding risk in this population has never been tested in an 'ad hoc' clinical trial. Patients over 75 years of age with NVAF were randomised to receive warfarin to maintain the INR at 1.8 (range 1.5-2.0) or at a standard target of 2.5 (range 2.0-3.0). There were 135 patients in the low-intensity and 132 in the standard-intensity groups. During a mean follow-up lasting 5.1 years, 59 primary outcome events (thromboembolism and major haemorrhage) were recorded, 24 (3.5 per 100 patient-years) in the low-intensity group and 35 (5.0 per 100 patient-years) in the standard-intensity group (HR=0.7, 95% CI 0.4-1.1, p=0.1). The reduction in the primary endpoint was mainly due to a diminution in major bleedings (1.9 vs. 3.0 per 100 patient-years; HR=0.6, 95% CI 0.3-1.2, p=0.1). The median achieved INR value was 1.86 in the low-intensity and 2.24 in the standard-intensity group (p<0.001). The frequency of INR testing was 26.1 +/- 13.5 vs. 24.3 +/- 11.6 days, p<0.0001). In this exploratory study we observed a low rate of stroke and major bleeding in elderly patients (>75) being managed in an anticoagulation clinic for primary stroke prevention with low-intensity anticoagulation (INR 1.5-2.0). However, further trials are needed to confirm the hypothesis generated by the present study.
观察到患有非瓣膜性心房颤动（NVAF）的老年患者从标准[国际标准化比值（INR）目标 2.0-3.0]口服抗凝治疗（OAT）中获益。在专门的临床试验中从未测试过低强度抗凝治疗可以抵消该人群更高的出血风险的假设。将 75 岁以上的 NVAF 患者随机分配接受华法林治疗，将 INR 维持在 1.8（范围 1.5-2.0）或标准目标 2.5（范围 2.0-3.0）。低强度组有 135 例患者，标准强度组有 132 例。在平均 5.1 年的随访期间，记录了 59 例主要结局事件（血栓栓塞和大出血），低强度组 24 例（每 100 患者年 3.5 例），标准强度组 35 例（每 100 患者年 5.0 例）（HR=0.7，95%CI 0.4-1.1，p=0.1）。主要终点的减少主要归因于大出血的减少（每 100 患者年 1.9 与 3.0 例；HR=0.6，95%CI 0.3-1.2，p=0.1）。低强度组的 INR 值中位数为 1.86，标准强度组为 2.24（p<0.001）。INR 检测频率为 26.1 +/- 13.5 与 24.3 +/- 11.6 天，p<0.0001）。在这项探索性研究中，我们观察到在抗凝诊所进行的用于初级卒中预防的低强度抗凝（INR 1.5-2.0）治疗的老年患者（>75 岁）中，卒中和大出血的发生率较低。然而，需要进一步的试验来证实本研究提出的假设。
