Meta-analysis of Stroke and Bleeding Risk in Patients with Various Atrial Fibrillation Patterns Receiving Oral Anticoagulants.

Oral anticoagulation therapy (OAT) is a mainstay for stroke prevention in atrial fibrillation (AF) patients. However, whether the risks of stroke/systemic embolic events (SEE) and bleeding events are affected by the type, duration, and frequency of AF in patients receiving OAT has been previously debated. We aimed to determine the risk of stroke/SEE and bleeding events associated with paroxysmal AF compared to persistent or permanent AF among patients who received OAT. Comprehensive literature searches of the Cochrane Library, PubMed/MEDLINE, and EMBASE databases were conducted from inception to July 2018. In total, 495 records were retrieved, of which 6 phase III randomized controlled trials (RCTs) focusing on the efficacy and safety of OAT in AF patients were ultimately evaluated and included. Among 70,447 AF patients, 15,028 (21.3%) patients had paroxysmal and 55,419 (78.7%) had persistent or permanent AF. Compared to persistent or permanent AF, the incidence of stroke/SEE was lower in paroxysmal AF patients (risk ratio [RR] 0.79, 95% confidence interval [CI] 0.71 to 0.88, P <0.00001, I2 = 0%). Overall, all-cause mortality was also lower in paroxysmal AF than in persistent or permanent AF patients (RR 0.72, 95% CI 0.66 to 0.79, P <0.00001, I2 =0%). Annualized major bleeding rates were similar across AF types (RR 1.06, 95% CI 0.96 to 1.17, P = 0.22, I 2= 35%). In conclusion, in patients with moderate-to-high risk of stroke receiving anticoagulation, those with paroxysmal AF have a lower risk of stroke, systemic embolism, and mortality but similar risk of major hemorrhage compared to persistent or permanent AF patients.