Abstract 9847: Association of Stroke and CHADSVASc With Left Atrial Scar in Patients Undergoing Catheter Ablation for Atrial Fibrillation

Introduction: Recurrent atrial fibrillation (AF) is estimated to occur in at least 20% of patients with paroxysmal or persistent AF who undergo catheter ablation (CA). Recent studies have suggested that extent of left atrial (LA) scar is of prognostic value, but it is unknown whether there is an association with patient co-morbidities. Hypothesis: Patients with structural heart disease or prior thromboembolic events have more LA scar and greater risk of AF recurrence. Methods: We retrospectively studied 117 patients who underwent CA for AF at our institution. Only ablations using the same method for radiofrequency ablation of pulmonary vein antra were included. We evaluated the association between demographic variables, LA volume, history of stroke, AF recurrence (defined as AF relapse more than 3 months after CA) and LA scar quantified by 3D electroanatomic mapping using simple regression and Kaplan-Meier analyses. Results: Mean age was 64 years, 68% were male, 60% had paroxysmal AF, 34% had persistent AF, and 6% had long-standing persistent AF. Recurrence of AF occurred in 22% of patients overall, and was significantly associated with systolic heart failure (HF) (p=0.042), number of prior cardioversions (CV) (p=0.014), left ventricular ejection fraction (LV EF) (p=0.02), LA volume (p=0.032), and atrial flutter (p=0.014). Total LA scar was significantly associated with CHA2DS2-VASc score (p=0.0095) and history of stroke or transient ischemic attack (TIA) (p=0.031). Conclusion: AF recurrence is more likely to occur in patients with LV dysfunction, prior CV, increased LA volume, and atrial flutter during CA. Total LA scar was not associated with clinical AF recurrence. However, we demonstrate a new association between LA scar burden, CHA2DS2-VASc score and history of stroke or TIA. This may explain why patients do not need to be in AF at the time they develop thromboembolic events, as enduring LA scar may contribute to the pathogenesis of stroke.