Arrhythmias and Conduction DisturbancesAnticoagulation, CHA2DS2VASc Score, and Thromboembolic Risk of Cardioversion of Acute Atrial Fibrillation (from the FinCV Study)

The efficacy of the anticoagulation in preventing thromboembolic complications (TEC) and the usefulness of the CHA2DS2VASc score for assessing stroke risk during cardioversion of acute atrial fibrillation (AF) are unclear. Thus, our objectives were to assess the ability of the CHA2DS2VASc score to predict TEC and to evaluate the efficacy of anticoagulation in the prevention of TEC in Finnish CardioVersion (FinCV) study. The FinCV is a retrospective, multicenter study of 3,143 patients, who underwent 7,660 cardioversions for acute AF. The value of the CHA2DS2VASc score in predicting TEC was analyzed separately in cardioversions performed without and with anticoagulation. A total of 40 definite TEC (0.6%) occurred after 7,237 successful cardioversions and 1 stroke (0.2%) after 423 unsuccessful procedures. In 5,362 cardioversions performed without anticoagulation, the risk of definite TEC increased significantly from 0.4% in patients with a CHA2DS2VASc score of 0 to 1 to 2.3% in those with score of ≥5 (p <0.001 for trend). The C-statistic of the CHA2DS2VASc score was 0.72 (0.61 to 0.83) in predicting definite TEC in non-anticoagulated patients with first cardioversion. The incidence of definite TEC was significantly lower in 2,298 cardioversions performed during anticoagulation (0.1% vs 0.7%, p = 0.001), and the preventive effect of anticoagulation was significant in patients with a score of ≥2 (0.2% vs 1.1%, p = 0.001). In conclusion, CHA2DS2VASc score is a strong predictor of TEC in cardioversion of acute AF performed without anticoagulation. Importantly, periprocedural anticoagulation reduced the risk of TEC by 82%. The overall risk of these complications was low after failed cardioversion.