NON-VKA ORAL ANTICOAGULANTS VERSUS VITAMIN K ANTAGONISTS IN PATIENTS UNDERGOING CARDIOVERSION FOR ATRIAL FIBRILLATION: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Clinical guidelines recommend peri-cardioversion anticoagulation in patients with atrial fibrillation (AF). We performed a systematic review and meta-analysis evaluating the safety and efficacy of non-VKA oral anticoagulants (NOACs) compared to vitamin K antagonists (VKAs) in patients with non-valvular AF undergoing cardioversion. We searched Cochrane CENTRAL, MEDLINE and EMBASE for randomized controlled trials (RCTs) and observational studies comparing NOACs to VKAs in patients undergoing cardioversion for AF. We performed title and abstract and full-text screening, data extraction and risk of bias evaluation independently and in duplicate. We pooled data using a random effects model and evaluated the overall quality of evidence using the GRADE framework. From 309 unique citations, we identified three eligible RCTs (n=5203) and seventeen eligible observational studies (n=9270) which reported outcomes of interest. The three RCTs and four of the observational studies were at low risk of bias. The median follow-up in RCTs was 42 days and thromboembolic events occurred in 0.18% of patients receiving NOACs, as compared to 0.55% receiving VKAs (relative risk (RR) 0.40, 95% CI [0.13, 1.24], I2=7%; moderate quality evidence). Major bleeding occurred in 0.42% of patients receiving NOACs as compared to 0.64% receiving VKAs (RR 0.62, 95% CI [0.28, 1.35], I2=0%; moderate quality evidence), and death occurred in 0.28% of patients receiving NOACs as compared to 0.38% receiving VKAs (RR 0.70, 95% CI [0.23, 2.10], I2=5%; low quality evidence). Observational studies reported lower thromboembolic risk with NOACs (RR 0.41, 95% CI [0.20, 0.83], I2=28%; very low quality evidence), but showed no significant difference in mortality (RR 1.21, 95% CI [0.53, 2.76], I2=0%; very low quality evidence) and bleeding (RR 0.59, 95% CI [0.32, 1.09], I2=45%; very low quality evidence). In anticoagulated patients with AF undergoing cardioversion, rates of adverse events are low. NOACs likely lead to reductions in thromboembolic events and bleeding. Based on these findings and their ease of use, NOACs should be the preferred therapy for patients with AF undergoing planned cardioversion.