Renal dysfunction and the risk of thromboembolic events in patients with atrial fibrillation after catheter ablation-The potential role beyond the CHA2DS2-VASc score

BACKGROUND Renal dysfunction is recognized as an important risk factor for thromboembolic (TE) events in patients with atrial fibrillation (AF) under medical treatment. OBJECTIVE To investigate whether renal dysfunction is a useful predictor of TE events among patients receiving AF ablation. We also aimed to determine whether the diagnostic accuracy of the CHA(2)DS(2)-VASc score in predicting TE events could be improved by adding renal dysfunction into the scoring system. METHODS We enrolled a total of 547 patients with AF who underwent catheter ablation. Renal dysfunction was defined as an estimated glomerular filtration rate of < 60 mL/min/1.73 m(2). The clinical end point was the occurrence of TE events (ischemic stroke, transient ischemic attack, or other systemic embolisms) during follow-up after catheter ablation. RESULTS During a follow-up of 38.9 +/- 22.5 months, 16 patients (2.9%) experienced TE events. Both the CHA(2)DS(2)-VASc score and renal dysfunction were independent predictors of TE events in the multivariate analysis. Among patients with a CHA(2)DS(2)-VASc score of 0 or 1, renal dysfunction can further stratify them into 2 groups with different event rates (4.3% vs 0.3%; P = .046). A new scoring system derived by assigning 1 more point representing renal dysfunction to the CHA(2)DS(2)-VASc score could improve its predictive accuracy; the area under the receiver operating characteristic curve increased from 0.84 to 0.88 (P = .043). CONCLUSIONS Renal dysfunction was a significant risk factor for TE events after catheter ablation of AF and may improve the diagnostic accuracy of the CHA(2)DS(2)-VASc score.