Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, 3755 Côte-Sainte-Catherine, H-461, Montreal, QC, Canada H3T 1E2 Department of Oncology, McGill University, Montreal, QC, Canada.
Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, 3755 Côte-Sainte-Catherine, H-461, Montreal, QC, Canada H3T 1E2.
Eur Heart J. 2014 Jul 21;35(28):1881-7. doi: 10.1093/eurheartj/eht499. Epub 2013 Dec 18.
An increased risk of stroke was observed in two atrial fibrillation (AF) trials of oral factor Xa inhibitors, when patients were transitioned to open label warfarin at the end of the study. The objective of this study is to determine whether initiation of warfarin is associated with an increased risk of stroke in patients with AF.
Using the UK Clinical Practice Research Datalink, a nested case-control analysis was conducted within a cohort of 70 766 patients with AF between 1993 and 2008. Stroke cases were randomly matched with up to 10 controls on age, sex, date of AF diagnosis, and time since AF diagnosis. Conditional logistic regression was used to estimate adjusted rate ratios (RRs) with 95% confidence intervals (CIs) of stroke associated with current warfarin use classified according to time since initiation of treatment (<30 days, 31-90 days, and >90 days), when compared with non-use. A total of 5519 patients experienced a stroke during follow-up. Warfarin was associated with a 71% increased risk of stroke in the first 30 days of use (RR: 1.71, 95% CI: 1.39-2.12), while decreased risks were observed with initiation >30 days before the event (31-90 days: RR: 0.50, 95% CI: 0.34-0.75 and >90 days: RR: 0.55, 95% CI: 0.50-0.61, respectively).
Patients initiating warfarin may be at an increased risk of stroke during the first 30 days of treatment, supporting the biological plausibility of a transient hypercoagulable state at the start of the treatment, although additional studies are needed to confirm these findings.
在两项口服因子 Xa 抑制剂治疗心房颤动（AF）的试验中，当研究结束时患者转换为开放标签华法林时，观察到中风风险增加。本研究的目的是确定 AF 患者开始使用华法林是否与中风风险增加相关。
利用英国临床实践研究数据链接，在 1993 年至 2008 年间进行了一项队列内的病例对照分析，该队列包含 70766 例 AF 患者。中风病例随机与年龄、性别、AF 诊断日期和 AF 诊断后时间相匹配的最多 10 个对照进行匹配。使用条件逻辑回归估计了调整后的率比（RR）及其 95%置信区间（CI），根据治疗开始后时间（<30 天、31-90 天和>90 天）分类，当前使用华法林与未使用的患者相比，与中风相关的风险。在随访期间，共有 5519 例患者发生中风。华法林在使用的前 30 天内与中风风险增加 71%相关（RR：1.71，95%CI：1.39-2.12），而在事件发生前 30 天以上开始使用时风险降低（31-90 天：RR：0.50，95%CI：0.34-0.75 和>90 天：RR：0.55，95%CI：0.50-0.61）。
开始使用华法林的患者在治疗的前 30 天内可能处于中风风险增加的状态，尽管需要进一步的研究来证实这些发现，但这支持了治疗开始时短暂的高凝状态的生物学合理性。
