BLEEDING RISK IN ATRIAL FIBRILLATION PATIENTS: The AMADEUS study.
Chest. 2011 Mar 17;
Authors: Lane DA, Kamphuisen PW, Minini P, Büller HR, Lip GY
ABSTRACT BACKGROUND: To assess the impact of combination antithrombotic therapy on stroke and bleeding risk compared to anticoagulation alone in atrial fibrillation (AF) patients. METHODS: Post-hoc analysis of 4576 AF patients [mean (SD) age 70.1 (9.1) years, 66.5% men] enrolled in the AMADEUS trial, randomised to receive either subcutaneous idraparinux (2.5mg weekly, n=2283) or dose-adjusted vitamin K antagonists (VKAs) (INR 2.0-3.0, n=2293). Of these, 848 (18.5%) patients used antiplatelet therapy (aspirin, clopidogrel, ticlopidine, etc) in addition to anticoagulation (combination antithrombotic therapy). RESULTS: 572 (15.3% per year) clinically relevant and 103 (2.6% per year) major bleeds occurred. Patients on combination antithrombotic therapy had 2.3 to 2.5-fold increased risk of clinically relevant bleeds and major bleeds, respectively, compared to those on anticoagulation alone. Multivariate analyses [HR, (95% CI)] revealed that the risk of clinically relevant bleeding was significantly increased by age 65 to 74 years [1.44 (1.14-1.82)] and ?75 years [1.59 (1.24-2.04)] (p=0.001), and by combination antithrombotic therapy [2.47 (2.07-2.96); p<0.0001]. The same held true for major bleeds, with analogous figures [HR (95% CI)] for age [65-74 years 2.26 (1.08-4.71) & ?75 years 4.19 (1.98-8.87; p=0.0004) and for combination antithrombotic therapy [2.23 (1.49-3.34); p<0.0001]. Combination antithrombotic therapy was not associated with a decrease in ischaemic stroke risk compared to anticoagulation alone [11 (1.4%) vs. 22 (0.7%) per year; adjusted HR 2.01 (95% CI 0.94 to 4.30); p=0.07]. CONCLUSIONS: Combination antithrombotic therapy increases the risk of clinically relevant bleeding and major bleeding in AF patients and does not appear to reduce the risk of stroke.
PMID: 21415134 [PubMed - as supplied by publisher]