R₂CHADS₂ Score and Thromboembolic Events After Catheter Ablation of Atrial Fibrillation in Comparison With the CHA₂DS₂-VASc Score

Background: A new risk model, the R₂CHADS₂ (Renal Dysfunction, Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack) score, was proposed to be a powerful scoring scheme in predicting stroke or systemic embolism in atrial fibrillation (AF). The goal of the present study is to validate the usefulness of the R₂CHADS₂ score among patients with AF after catheter ablation. We also aimed to compare the accuracy of the CHA₂DS₂-VASc (Congestive Heart Failure, Hypertension, Age [≥ 75 y], Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age [65-74 y], Sex [Female]) and R₂CHADS₂ scores for risk stratification of thromboembolic (TE) events after ablation procedures. Methods: We enrolled a total of 526 patients with AF who underwent catheter ablation. The clinical end point was the occurrence of TE events (ischemic stroke, transient ischemic attack, or other systemic embolisms) during the postablation follow-up. Results: During a follow-up of 37.5 ± 21.3 months, 14 patients (2.7%) experienced TE events. The R₂CHADS₂ score was an independent predictor of TE events in the multivariate analysis. Patients with an R₂CHADS₂ score of > 2 had a higher event rate compared with those with a score of 0 or 1 (0.5% vs 7.7%). The areas under the receiver operating characteristic (ROC) curves of CHA₂DS₂-VASc and R₂CHADS₂ scores in predicting TE events were 0.832 and 0.872, respectively. The difference between these 2 curves did not reach statistical significance (P= 0.338). In addition, the R₂CHADS₂ score did not improve net stroke risk reclassification over the CHA₂DS₂-VASc score (net reclassification improvement,-0.9%; P= 0.948). Conclusions: The R₂CHADS₂ and CHA₂DS₂-VASc scores could be used to predict TE events for patients with AF undergoing catheter ablation. The predictive accuracy of both scores were similar in this relatively small cohort undergoing ablation.