Role of CHADS2 Score in Evaluation of Thromboembolic Risk and Mortality in Patients With Atrial Fibrillation Undergoing Direct Current Cardioversion (from the ACUTE Trial Substudy)

The CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, stroke or transient ischemic attack [2 points]) scoring scheme has been found to be a good predictor of stroke risk in patients with nonvalvular atrial fibrillation (AF). However, the value of the CHADS2 scoring system in the risk stratification of patients with AF who undergo direct-current cardioversion has not yet been specifically investigated. In this study, a subgroup of 541 patients from the Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) study who had AF for >48 hours and planned to undergo transesophageal echocardiography before direct-current cardioversion were enrolled. Each patient had a CHADS2 score calculated. Of the patients with CHADS2 scores of 0, 14 (10%) were found to have left atrial appendage thrombi on transesophageal echocardiography. After 6 months of follow up, patients with CHADS2 scores of 3 to 6 showed a significantly higher mortality rate in comparison with patients with lower CHADS2 scores (4.3% vs 0.5%, p = 0.004), despite their similar prevalence of left atrial appendage thrombus and stroke (thrombus: 13.4% vs 11.6%, p = 0.60; stroke: 0% vs 0.3%, p = 0.70). In conclusion, the CHADS2 scoring system may be useful for predicting short-term mortality risk in patients with AF receiving elective direct-current cardioversion. However, in the preprocedural risk assessment of these patients, the CHADS2 scoring system is not reliable in predicting risk for left atrial appendage thrombus formation, especially in patients with low CHADS2 scores.