Singer Daniel E, Hughes Robert A, Gress Daryl R, Sheehan Mary A, Oertel Lynn B, Maraventano Sue Ward, Blewett Dyan Ryan, Rosner Bernard, Kistler J Philip
N Engl J Med. 1990 Nov 29;323(22):1505-11. doi: 10.1056/NEJM199011293232201.
Nonrheumatic atrial fibrillation increases the risk of stroke, presumably from atrial thromboemboli. There is uncertainty about the efficacy and risks of long-term warfarin therapy to prevent stroke.
We conducted an unblinded, randomized, controlled trial of long-term, low-dose warfarin therapy (target prothrombin-time ratio, 1.2 to 1.5) in patients with nonrheumatic atrial fibrillation. The control group was not given warfarin but could choose to take aspirin.
A total of 420 patients entered the trial (212 in the warfarin group and 208 in the control group) and were followed for an average of 2.2 years. Prothrombin times in the warfarin group were in the target range 83 percent of the time. Only 10 percent of the patients assigned to receive warfarin discontinued the drug permanently. There were 2 strokes in the warfarin group (incidence, 0.41 percent per year) as compared with 13 strokes in the control group (incidence, 2.98 percent per year), for a reduction of 86 percent in the risk of stroke (warfarin:control incidence ratio = 0.14; 95 percent confidence interval, 0.04 to 0.49; P = 0.0022). There were 37 deaths altogether. The death rate was markedly lower in the warfarin group than in the control group: 2.25 percent as compared with 5.97 percent per year, for an incidence ratio of 0.38 (95 percent confidence interval, 0.17 to 0.82; P = 0.005). There was one fatal hemorrhage in each group. The frequency of bleeding events that led to hospitalization or transfusion was essentially the same in both groups. The warfarin group had a higher rate of minor hemorrhage than the control group (38 vs. 21 patients).
Long-term low-dose warfarin therapy is highly effective in preventing stroke in patients with non-rheumatic atrial fibrillation, and can be quite safe with careful monitoring.
非风湿性心房颤动会增加中风风险，可能是由于心房血栓栓塞所致。长期使用华法林预防中风的疗效和风险尚不确定。
我们对非风湿性心房颤动患者进行了一项非盲、随机、对照试验，采用长期低剂量华法林治疗（目标凝血酶原时间比值为1.2至1.5）。对照组未给予华法林，但可选择服用阿司匹林。
共有420例患者进入试验（华法林组212例，对照组208例），平均随访2.2年。华法林组凝血酶原时间在目标范围内的时间占83%。分配接受华法林治疗的患者中只有10%永久停药。华法林组有2例中风（发生率为每年0.41%），而对照组有13例中风（发生率为每年2.98%），中风风险降低了86%（华法林组与对照组的发生率比值=0.14；95%置信区间为0.04至0.49；P = 0.0022）。共有37例死亡。华法林组的死亡率明显低于对照组：分别为每年2.25%和5.97%，发生率比值为0.38（95%置信区间为0.17至0.82；P = 0.005）。每组各有1例致命性出血。导致住院或输血的出血事件发生率在两组中基本相同。华法林组轻微出血的发生率高于对照组（38例对21例）。
长期低剂量华法林治疗对预防非风湿性心房颤动患者的中风非常有效，并且在仔细监测下相当安全。
