Introduction: Pulmonary vein isolation (PVI) is a recommended strategy for rhythm control in atrial fibrillation (AF), but its success rate remains unsatisfactory. Continuous research is being conducted to explore new technologies and modifications to the existing ablation workflow in order to reduce the arrhythmia recurrence rate.
Objectives: This study aimed to determine the influence of the distance between ablation lines (DBL) on AF recurrence rate in patients undergoing their first PVI; and thus to optimize the procedure outcomes.
Patients and methods: This is a retrospective cohort study conducted at a tertiary care center in Poland. A total of 146 patients (median age, 62 years; women, 34.3%) referred for a first PVI for either paroxysmal (n = 103) or persistent (n = 43) AF were evaluated. The procedures were performed with the use of a very‑high‑power, short‑duration catheter (QDot MicroTM, Biosense Webster, Inc., Irvine, California, United States) or a conventional, ablation index-guided ThermoCool Smarttouch SF catheter (Biosense Webster, Inc.). Freedom from AF recurrence was used as a primary end point. The impact of DBL on the outcome of PVI, accounting for conventional risk factors, was evaluated.
Results: Greater distance between opposite circumferential PVI lines and its ratio to the transverse diameter of the left atrium (DLB/TD) were associated with a lower risk of AF recurrence (hazard ratio [HR], 0.966; 95% CI, 0.935-0.998 [per 1 mm]; P = 0.04 and HR, 0.968; 95% CI, 0.944-0.993 [per 1%]; P = 0.01, respectively). There was no correlation between DBL or DBL/TD ratio and the impedance level.
Conclusions: Close distance between PVI lines contributes to AF recurrence; thus, increasing the DBL and ensuring a higher DBL/TD ratio may be an advantageous ablation strategy.