Clinical impact of contact force and its regional variability on efficiency and effectiveness of pulmonary vein isolation for atrial fibrillation

Background: The purpose of this study is to analyze the impact of average contact force (CF) and its regional variability during pulmonary vein isolation (PVI) for atrial fibrillation (AF) on periprocedural parameters and midterm outcome. Methods: This retrospective cohort study enrolled 57 drug-refractory AF patients who underwent initial PVI for AF using an open-irrigated CF catheter (SmartTouch Thermocool, Biosense Webster, Diamond Bar, CA, USA). Thirty patients were assigned to a lower CF (LCF) group (average CF <= 10 g) and 27 patients to a higher CF (HCF) group (average CF > 10 g). The relationship between CF and clinical outcome was analyzed. Results: Patients were followed-up for 317 +/- 57 days after PVI. The CF was 8.1 +/- 1.3 gin the LCF group and 12.4 +/- 1.5 gin the HCF group. Higher average CF was associated with shorter ablation time (28 +/- 6 min vs. 36 +/- 9 min, p = 0.0002) and lower radiofrequency energy delivery (79 +/- 18 vs. 99 +/- 26, p = 0.0016) for PVI. The rate of acute PV reconnection (APVR) was similar in both groups (LCF group 60% vs. HCF group 44%, p = 0.36). Four patients (13%) in the LCF group and nine patients (33%) in the HCF group experienced AF recurrence. Average CF did not impact on AF-recurrence during midterm clinical outcome (p = 0.09 by log rank test). In the non-recurrence group (n = 44), average CF was higher at left posterosuperior PV and right anteroinferior PV than that in the recurrence group (n = 13) (p = 0.012 and p = 0.004, respectively). Conclusions: Higher average CF decreased ablation time and radiofrequency energy delivery for PVI, but did not decrease APVR rate or improve midterm clinical outcome. (C) 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.