Comparative effects of antiplatelet, anticoagulant, or combined therapy in patients with valvular and nonvalvular atrial fibrillation: A randomized multicenter study

Objectives This trial evaluated the efficacy and safety of the combination of antiplatelet and moderate-intensity anticoagulation therapy in patients with atrial fibrillation associated with recognized risk factors or mitral stenosis. Background Warfarin was more effective than aspirin in preventing stroke in these patients; combined therapy with low anticoagulant intensity was ineffective. Mitral stenosis patients were not investigated. Methods We performed a multicenter randomized trial in 1,209 patients at risk. The intermediate-risk group included patients with risk factors or age >60 years: 242 received the cyclooxygenase inhibitor triflusal, 237 received acenocumarol, and 235 received a combination of both. The high-risk group included patients with prior embolism or mitral stenosis: 259 received anticoagulants and 236 received the combined therapy. Median follow-up was 2.76 years. Primary outcome was a composite of vascular death and nonfatal stroke or systemic embolism. Results Primary outcome was lower in the combined therapy than in the anticoagulant arm in both the intermediate- (hazard ratio [HR] 0.33 [95% confidence interval (CI)0.12 to 0.91]; p = 0.02) and the high-risk group (HR 0.51 [95% CI 0.27 to 0.96]; p = 0.03). Primary outcome plus severe bleeding was lower with combined therapy in the intermediate-risk group. Nonvalvular and mitral stenosis patients had similar embolic event rates during anticoagulant therapy. Conclusions The combined antiplatelet plus moderate-intensity anticoagulation therapy significantly decreased the vascular events compared with anticoagulation alone and proved to be safe in atrial fibrillation patients.