Renal dysfunction, stroke risk scores (CHADS2, CHA2DS2-VASc, and R2CHADS2), and the risk of thromboembolic events after catheter ablation of atrial fibrillation: the Leipzig Heart Center AF Ablation Registry.

BACKGROUND: There are limited data on the predictive value of stroke risk scores for thromboembolic events (TEs) after catheter ablation of atrial fibrillation (AF). Our objectives were to report the incidence of TEs after AF ablation in a large contemporary AF ablation cohort and to investigate the impact of renal dysfunction and the value of stroke risk stratification scores (CHADS2, CHA2DS2-VASc, and R2CHADS2) for predicting TE after AF ablation. METHODS AND
RESULTS: Using the Leipzig Heart Center AF Ablation Registry, we documented TEs in patients undergoing radiofrequency AF catheter ablation. TE was defined as stroke, transient ischemic attack, or systemic embolism. Study population (N=2069; 66% men; 60±10 years; 62% paroxysmal AF; mean CHADS2, 1.2±0.9; CHA2DS2-VASc, 2.1±1.4; and R2CHADS2, 1.3±1.1) were followed up for a median 18 (Q1-Q3, 12-29) months (ie, 3078 patient-years). Overall, 31 TEs occurred, with 16 events within 30 days of ablation and 15 TEs (0.72%) during the follow-up period. On multivariate analysis, CHADS2 (P<0.001), R2CHADS2 (P<0.001), and CHA2DS2-VASc (P=0.003) scores were independent predictors of TEs during follow-up, and AF recurrence conferred a nonsignificant trend for increased TE risk (P=0.071-0.094). The CHA2DS2-VASc score further differentiated TE risk in patients with CHADS2 and R2CHADS2 0 to 1 (0.13% if CHA2DS2-VASc was 0-1 and 0.71% if CHA2DS2-VASc was >2) and had the best predictive value in patients with AF recurrences (c-index 0.894, P=0.022 versus CHADS2, P=0.031 versus R2CHADS2).
CONCLUSIONS: CHADS2, CHA2DS2-VASc, and R2CHADS2 scores were associated with TE risk. The CHA2DS2-VASc score differentiated TE risk in the low-risk strata based on CHADS2 and R2CHADS2 scores and may be superior in the subgroup with AF recurrences.