Thromboembolic complications after cardioversion of acute atrial fibrillation: the FinCV (Finnish CardioVersion) study.
OBJECTIVES
This study sought to explore the incidence and risk factors of thromboembolic complications after cardioversion of acute atrial fibrillation.


BACKGROUND
Anticoagulation therapy is currently recommended after cardioversion of acute atrial fibrillation in patients with risk factors for stroke, but the implementation of these new consensus-based guidelines has been slow.


METHODS
A total of 7,660 cardioversions were performed in 3,143 consecutive patients with atrial fibrillation lasting <48 h in 3 hospitals. For this analysis, embolic complications were evaluated during the 30 days after 5,116 successful cardioversions in 2,481 patients with neither oral anticoagulation nor peri-procedural heparin therapy.


RESULTS
There were 38 (0.7%; 95% confidence interval [CI]: 0.5% to 1.0%) definite thromboembolic events (31 strokes) within 30 days (median 2 days, mean 4.6 days) after cardioversion. In addition, 4 patients suffered transient ischemic attack after cardioversion. Age (odds ratio [OR]: 1.05; 95% CI: 1.02 to 1.08), female sex (OR: 2.1; 95% CI: 1.1 to 4.0), heart failure (OR: 2.9; 95% CI: 1.1 to 7.2), and diabetes (OR: 2.3; 95% CI: 1.1 to 4.9) were the independent predictors of definite embolic events. Classification tree analysis showed that the highest risk of thromboembolism (9.8%) was observed among patients with heart failure and diabetes, whereas patients with no heart failure and age <60 years had the lowest risk of thromboembolism (0.2%).


CONCLUSIONS
The incidence of post-cardioversion thromboembolic complications is high in certain subgroups of patients when no anticoagulation is used after cardioversion of acute atrial fibrillation. (Safety of Cardioversion of Acute Atrial Fibrillation [FinCV]; NCT01380574).