PO-03-156 ACUTE AND LONG-TERM LESION DURABILITY AND RECONNECTION PATTERNS FOLLOWING HYBRID ATRIAL FIBRILLATION ABLATION

Background: Hybrid ablation (AF) is a well-established rhythm control strategy in non-paroxysmal AF patients.Data on need for endocardial touch-up acutely after epicardial ablation are limited, as well as long-term reconnection patterns in patients undergoing redo procedures. Objective: To evaluate the lesion transmurality detected via endocardial mapping acutely after epicardial radiofrequency (RF) ablation, as well as anatomical and clinical predictors of residual endocardial gaps in a large cohort of patients undergoing hybrid AF ablation. Furthermore, long-term lesion durability will be assessed in patients undergoing repeat endocardial ablation. Methods: Hybrid procedures were performed in a one-step fashion (endocardial mapping +/- ablation immediately following left thoracoscopy epicardial ablation). Epicardial pulmonary vein (PV) isolation was achieved via a bipolar RF clamp; further epicardial linear ablation was performed with a RF bipolar linear device. At the end of the procedure, the left atrial appendage (LAA) was clipped. Results: A total of 130 patients were included (mean age: 65±9.4; 72.3% males); among them, 19.2% and 55.4% had persistent or long-standing persistent AF. All patients received epicardial PV and posterior wall (PW) isolation plus additional RF applications to the LAA/posterolateral ridge. In 13.1% (n=17) epicardial lesions could not be completed due to difficult anatomy. At the end of the procedure, an attempt to clip the LAA was done in all patients, resulting in 97.7% success (3 LAA clip failures due to anatomical reasons). Acute endocardial mapping revealed a PV reconnection rate of 4.6% (n=24), left superior and right superior PVs being the veins most commonly reconnected (6.15% and 5.38%, respectively). PW reconnection was documented in 8.5 %. Multivariate analysis showed left atrial (LA) volume and male gender as predictors for acute endocardial gaps after complete epicardial lesions. A redo procedure after first recurrence was performed in 24.6% (n=32), showing lesion durability of 100% for left PVs, 90.6% for right superior and 93.7% for right inferior PVs. PW remained isolated in 78.1% of patients. Age was a predictive factor for chronic gaps after recurrence. At a mean follow-up of 51±35 months, arrhythmia-free survival after multiple procedures was 68.5%. Conclusion: In a large cohort of AF patients undergoing hybrid ablation, acute and chronic lesion durability was high. LA volume and male gender were predictors of acute reconnection after epicardial ablation.