Bleeding risk of antiplatelet drugs compared with oral anticoagulants in older patients with atrial fibrillation: a systematic review and meta-analysis.

Background The hemorrhagic risk of antiplatelet drugs in older patients could be higher than is usually assumed. Objective To compare the bleeding risk of antiplatelet drugs and oral anticoagulants in elderly patients. Methods We carried out a systematic review and meta-analysis. We searched PubMed, EMBASE and the Cochrane Library up to January 2016 for randomized and non-randomized controlled trials (RCTs) and parallel cohorts comparing antiplatelet drugs and oral anticoagulants in patients aged 65 years or older. Two independent authors assessed studies for inclusion. The pooled relative risk (RR) of major bleeding was estimated using a random model. Results Seven RCTs (4550 patients) and four cohort studies (38 649 patients) met the inclusion criteria. The risk of major bleeding when on aspirin or clopidogrel was equal to that when on warfarin in RCTs (RR, 1.01; 95% confidence interval (95% CI), 0.69-1.48; moderate-quality evidence), lower than when on warfarin in non-randomized cohort studies (RR, 0.87; 95% CI, 0.77-0.99; low-quality evidence) and not different when all studies were combined (RR, 0.86; 95% CI, 0.73-1.01). Bleeding of any severity (RR, 0.70; 95% CI, 0.57-0.86) and intracranial bleeding (RR, 0.46; 95% CI, 0.30-0.73) were less frequent with antiplatelet drugs than with warfarin. All-cause mortality was similar (RR, 0.99). Subgroup analysis suggested that major bleeding might be higher with warfarin than with aspirin in patients over 80 years old. Conclusion Elderly patients treated with aspirin or clopidogrel suffer less any-severity bleeding but have a risk of major bleeding similar to that of oral anticoagulants, with the exception of intracranial bleeding.