Abstract 17638: Left Atrial Scar Burden Among Patients With Persistent Atrial Fibrillation Undergoing Catheter Ablation and Its Association With Patient Risk Factors and Risk of Recurrence

Introduction: Left atrial (LA) scar at time of catheter ablation (CA), assessed by bipolar voltage <0.5mV may indicate more advanced AF substrate. It is not known which risk factors are associated with scar burden and whether this is linked to worse clinical outcomes.

Hypothesis: We hypothesized that patient demographics and comorbidities are associated with greater scar burden at time of CA and predispose to AF recurrence.

Methods: The Real-AF registry is a prospective, observational, multicenter registry of patients undergoing CA with follow-up at 6 and 12 months. LA scar burden was calculated from CARTO as total % LA area < 0.50mV bipolar using the Pentaray catheter at first CA for persistent AF. We evaluated 1503 patients among this cohort using logistic regression modeling of age, sex, CHA2DS2-VASc and LVEF <= 35%, BMI and their association with LA scar burden categorized as 0 to 5% vs >= 6%. In 783 patients with 12-month clinical outcomes a Kaplan-Meier estimator was used to analyze risk of AF recurrence in these two cohorts.

Results: Each additional year in age is associated with 1.07 greater odds (p<0.001, 95% CI=1.05, 1.08) of scar area >= 6%. Women had 2.08 greater odds (p<0.001, 95% CI=1.63, 2.65) of abnormal scar area compared to men, while patients with CHF had 1.67 greater odds (p<0.001, 95% CI=1.30, 2.16). Patients with LA scar burden >= 6% experienced significantly higher recurrence of AF compared to those with a lower scar burden (HR=1.8, p=0.0094) including after controlling for operator-specific effects (HR=1.9, p=0.0088), see figure 1.

Conclusions: In a large multicenter registry of persistent AF patients undergoing CA, LA scar >=6% was associated with female sex, greater age, and CHF. An increased scar burden is associated with worse 12 month clinical outcomes from CA.