Long-Term Predictors of Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients Undergoing Electrical Cardioversion

Background: Patients with nonvalvular atrial fibrillation (AF) who undergo electrical cardioversion (ECV) tend to be younger and have less comorbidity. Long-term anticoagulation after ECV should be based on thromboembolic risk. We sought to study the long-term incidence of thromboembolic events (TE), factors related to TE and compare the predictive value of the CHADS(2) and CHA(2)DS(2)-VASc scores in this particular population. Methods and Results: From January 2008 to June 2012, 571 ECV were performed in 406 consecutive patients with nonvalvular AF. Risk factors for TE and factors related to anticoagulation therapy after ECV were registered. During a follow-up of approximately 2 years, the annual incidence of TE was 1.9%. Factors associated with TE were: poor quality anticoagulation control (hazard ratio [HR]: 2.91; 95% confidence interval [CI]: 1.10-7.80; P=0.03), cessation of anticoagulation after ECV (HR: 8.80; 95% CI: 3.11-25.10; P= 65 years (HR: 13.65; 95% CI: 1.74-107.16; P=0.01), CHADS(2) score (HR: 1.59; 95% CI: 1.10-2.29; P=0.01) and CHA(2)DS(2)-VASc score (HR: 1.67; 95% CI: 1.30-2.22; P