Effect of intensity of oral anticoagulation on stroke severity and mortality in atrial fibrillation
Effect of intensity of oral anticoagulation on stroke severity and mortality in atrial fibrillation
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DOI：
10.1056/nejmoa022913
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发表时间：
2003-09-11
影响因子：
158.5
通讯作者：
Singer, DE
中科院分区：
文献类型：
--
作者：
Hylek, EM;Go, AS;Singer, DE
背景：口服抗凝药物可以大大降低心房颤动患者中风的发生率，在国际标准化比值 (INR) 值为 2.0 或更高时可以看到完全效果。口服抗凝药物的强度对心房颤动相关卒中严重程度的影响尚不清楚，但对于目标 INR 的选择至关重要。方法：我们研究了 13,559 名非瓣膜性心房颤动患者的缺血性卒中事件。通过住院数据库识别中风，并根据病历进行验证，病历还提供有关华法林或阿司匹林的使用、入院时的 INR 以及合并疾病的信息。根据改良的兰金量表对中风的严重程度进行分级。根据住院和死亡档案确定 30 天死亡率。结果：在 596 例缺血性中风中，32% 发生在华法林治疗期间，27% 发生在阿司匹林治疗期间，42% 发生在两种治疗期间。在服用华法林的患者中，入院时 INR 低于 2.0 与 INR 为 2.0 或更高相比，在比例比数 Logistic 回归模型中（比值比为 1.9；95% 置信区间为 1.1 至 3.4），三个严重程度类别中发生严重卒中的几率独立增加，并且增加了 30 天内死亡的风险（风险比为 3.4；95% 置信区间， 1.1 至 10.1）。入院时 INR 为 1.5 至 1.9 时的死亡率与 INR 低于 1.5 时的死亡率相似（分别为 18% 和 15%）。中风时服用阿司匹林的患者的 30 天死亡率与服用华法林且 INR 低于 2.0 的患者相似。结论：在非瓣膜性心房颤动患者中，INR 为 2.0 或更高的抗凝治疗不仅可以降低缺血性中风的频率，还可以降低其严重程度和中风死亡风险。我们的研究结果提供了进一步的证据，反对在房颤患者中使用较低的 INR 目标水平。
Background: The incidence of stroke in patients with atrial fibrillation is greatly reduced by oral anticoagulation, with the full effect seen at international normalized ratio (INR) values of 2.0 or greater. The effect of the intensity of oral anticoagulation on the severity of atrial fibrillation-related stroke is not known but is central to the choice of the target INR.Methods: We studied incident ischemic strokes in a cohort of 13,559 patients with nonvalvular atrial fibrillation. Strokes were identified through hospitalization data bases and validated on the basis of medical records, which also provided information on the use of warfarin or aspirin, the INR at admission, and coexisting illnesses. The severity of stroke was graded according to a modified Rankin scale. Thirty-day mortality was ascertained from hospitalization and mortality files.Results: Of 596 ischemic strokes, 32 percent occurred during warfarin therapy, 27 percent during aspirin therapy, and 42 percent during neither type of therapy. Among patients who were taking warfarin, an INR of less than 2.0 at admission, as compared with an INR of 2.0 or greater, independently increased the odds of a severe stroke in a proportional-odds logistic-regression model (odds ratio, 1.9; 95 percent confidence interval, 1.1 to 3.4) across three severity categories and the risk of death within 30 days (hazard ratio, 3.4; 95 percent confidence interval, 1.1 to 10.1). An INR of 1.5 to 1.9 at admission was associated with a mortality rate similar to that for an INR of less than 1.5 (18 percent and 15 percent, respectively). The 30-day mortality rate among patients who were taking aspirin at the time of the stroke was similar to that among patients who were taking warfarin and who had an INR of less than 2.0.Conclusions: Among patients with nonvalvular atrial fibrillation, anticoagulation that results in an INR of 2.0 or greater reduces not only the frequency of ischemic stroke but also its severity and the risk of death from stroke. Our findings provide further evidence against the use of lower INR target levels in patients with atrial fibrillation.