Determinants of Acute and Late Pulmonary Vein Reconnection in Contact Force–Guided Pulmonary Vein Isolation

Catheter-based pulmonary vein isolation (PVI) is associated with a single procedure freedom from atrial fibrillation (AF) in ≈70% of patients with paroxysmal AF. Lack of durability of PVI, a major determinant of AF recurrence, is evidenced by acute PV reconnection at the time of the procedure and late pulmonary vein reconnection (PVR) during followup. The use of contact force (CF)–sensing catheters, allowing to better control stability and lesion depth during point-by-point PV encircling, has improved freedom from AF now amounting to ≈80%. Nevertheless, acute and late PVR still occur, and data on 1-year outcome are not consistent across studies. We aimed to investigate whether acute and late PVR in CF-guided ablation are because of incomplete transmural or discontiguous radiofrequency lesions within the deployed PV circle and whether criteria can be set forward as targets to avoid weak links in the ablation chain. Criteria for lesion depth implied time of application, median delivered power, impedance drop, average CF, force–time integral (FTI), and ablation index (AI). Contiguity was assessed by calculating automated interlesion distance. Ablation line contiguity index (ALCI) was developed as a novel automated algorithm to assess both depth and contiguity.