JAMA：降低房颤女性卒中风险仍需新策略

5月9日，《美国医学会杂志》（JAMA）发表的一项以人口为基础的大规模队列研究表明，无论女性房颤患者是否服用华法林或风险特征如何，其卒中风险均高于男性。

既往多项有关房颤患者的研究表明，女性卒中风险比男性高40%~70%。造成这一差异的原因尚不清楚，但有人推测可能与女性较少接受华法林预防治疗有关。为此，加拿大麦克吉尔大学健康中心临床流行病学室的Meytal Avgil Tsadok博士及其同事评估了83,000余例魁北克老年房颤患者的华法林使用情况和此后卒中发生率。这些患者在1998~2007年期间出院时主要或次要诊断为房颤，其中男性39,398例，女性44,115例，入院年龄均≥65岁。

随访结果显示，女性卒中发生粗率(5.8%)显著高于男性(4.3%)，女性卒中总发生率为2.02/100(人·年)，而男性为1.61/100(人·年)。校正合并症、卒中风险因素和华法林使用情况后的多变量分析显示，女性卒中风险仍然较高，危险比(HR)为1.14。女性华法林处方率(60.6%)略高于男性(58.2%)。华法林治疗依从性均较好，华法林使用和依从性程度对男女患者卒中风险均无影响。除性别因素外，最主要的独立卒中危险因素为卒中史。对无卒中史患者亚组分析显示，女性卒中风险仍高于男性，HR为1.17。卒中发病率性别差异主要来自高龄患者(>75岁)，女性和男性分别为2.38和1.95/100(人·年)。

上述结果表明，华法林使用与否并不是男女卒中风险差异的重要原因，并提示目前采取的抗凝治疗措施不足以预防老年女性卒中，尚需采取新的策略以进一步降低房颤女性卒中风险。同时也表明，75岁以上老年女性是房颤患者卒中预防的最重要目标人群，在临床实践中需密切监测新抗凝剂对该类人群的有效性。

doi:10.1001/jama.2012.3490
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Sex Differences in Stroke Risk Among Older Patients With Recently Diagnosed Atrial FibrillationSex Differences In Stroke Risk In Patients With AF

Meytal Avgil Tsadok, PhD; Cynthia A. Jackevicius, PharmD, MSc; Elham Rahme, PhD; Karin H. Humphries, DSc; Hassan Behlouli, PhD; Louise Pilote, MD, MPH, PhD

Context  Stroke is a serious complication associated with atrial fibrillation (AF). Women with AF are at higher risk of stroke compared with men. Reasons for this higher stroke risk in women remain unclear, although some studies suggest that undertreatment with warfarin may be a cause.

Objective  To compare utilization patterns of warfarin and the risk of subsequent stroke between older men and women with AF at the population level.

Design, Setting, and Patients  Population-based cohort study of patients 65 years or older admitted to the hospital with recently diagnosed AF in the province of Quebec, Canada, 1998-2007, using administrative data with linkage between hospital discharge, physicians, and prescription drug claims databases.

Main Outcome Measures  Risk of stroke.

Results  The cohort comprised 39 398 men (47.2%) and 44 115 women (52.8%). At admission, women were older and had a higher CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack) score than men (1.99 [SD, 1.10] vs 1.74 [SD, 1.13], P < .001). At 30 days postdischarge, 58.2% of men and 60.6% of women had filled a warfarin prescription. In adjusted analysis, women appeared to fill more warfarin prescriptions compared with men (odds ratio, 1.07 [95% CI, 1.04-1.11]; P < .001). Adherence to warfarin treatment was good in both sexes. Crude stroke incidence was 2.02 per 100 person-years (95% CI, 1.95-2.10) in women vs 1.61 per 100 person-years (95% CI, 1.54-1.69) in men (P < .001). The sex difference was mainly driven by the population of patients 75 years or older. In multivariable Cox regression analysis, women had a higher risk of stroke than men (adjusted hazard ratio, 1.14 [95% CI, 1.07-1.22]; P < .001), even after adjusting for baseline comorbid conditions, individual components of the CHADS2 score, and warfarin treatment.

Conclusion  Among older patients admitted with recently diagnosed AF, the risk of stroke was greater in women than in men, regardless of warfarin use.