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 CHA₂DS 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 m². 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 CHA₂DS ₂-VASc score and renal dysfunction were independent predictors of TE events in the multivariate analysis. Among patients with a CHA ₂DS₂-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 CHA₂DS₂-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 CHA₂DS₂-VASc score.