Abstract 16597: Increased Risk of Major Bleeding Complications in Women During Vka Treatment for Acute Venous Thromboembolism
Background: Studies on patients with atrial fibrillation have reported higher risks of major bleeding in women than in men during treatment with vitamin K-antagonists (VKA). Information on whether this relationship between sex and major bleeding also exists in patients treated with VKA for acute venous thromboembolism (VTE), is scarce.
Aim: To analyse whether sex differences exist in the risks of major bleeding and recurrent VTE during VKA therapy for acute VTE.
Methods: Consecutive patients with a first episode of VTE treated with VKA between 2003-2009 were included. Primary outcomes were major bleeding defined by the ISTH criteria, and recurrent VTE. Risks of study outcomes to occur were compared between women and men and reported as crude hazard ratios (HR), and HRs adjusted for age, use of platelet inhibitors, hypertension and diabetes mellitus. Time within therapeutic range (TTR) was compared between both sexes using a Mann-Whitney U-test.
Results: 1868 women and 1674 men were included. Median duration of follow-up was 173 days (2.5-97.5percentiles12.4-1716.3 days). In total 49/1868 women (7.9/100 py, 95% CI6.0-10.3) and 23/1674 men (3.8/100 py, 95% CI2.5-5.6) developed a major bleeding event; crude and adjusted hazard ratios 1.9(95%CI1.2-3.2) and 1.7(95%CI1.0-2.7), respectively. Recurrent VTE occurred in 30/1868 women (4.9/100py, 95%CI3.4-7.0) and 30/1674 men (5.1/100 py, 95%CI3.6-7.3), with crude and adjusted HRs of 0.9 (95%CI for both crude and adjusted HRs 0.5-1.5). Median TTR for women was 75.6 % (2.5-97.5 percentile 14.1-100%) versus 77.7% (2.5-97.5 percentile 19.7-100.0%) for men, p <0.0001.
Conclusions: Women are at increased risk for major bleeding complications during VKA therapy for acute VTE, which might be due to lower TTR values found in women. Further research is needed to analyse whether women would benefit from less intensive anticoagulant treatment.
- © 2013 by American Heart Association, Inc.