Aims: In many laboratories, cooled-tip catheters have replaced 8 mm-tip catheters due to their theoretical advantage of achieving larger lesions and avoiding charring. However, direct comparisons between the catheters in the subset of atrial fibrillation (AF) ablation are scarce. The aim of this study was to compare the efficacy, safety, and lesion extension created by 8 mm-tip vs. cooled-tip catheter with different energy settings for circumferential pulmonary vein ablation (CPVA).
Methods and results: A series of 221 consecutive patients with symptomatic AF were included in the study. Circumferential pulmonary vein ablation was performed using an 8 mm-tip catheter (55 W, 50 degrees C) in 90 patients (Group 1), a cooled-tip (30 W, 45 degrees C) in 42 (Group 2), and a cooled-tip (40 W, 45 degrees C) in 89 (Group 3). In a subgroup of 60 patients, troponin I (TpnI), creatinine kinase, and myoglobin values were obtained before and at 12 and 24 h after ablation. At 1 year follow-up, the probability of being arrhythmia-free after a single procedure was 53, 35, and 55% in patients from Groups 1, 2, and 3, respectively. Ablation with a cooled-tip catheter at 30 W led to a higher recurrence rate (P = 0.030) and was identified in Cox regression analysis as an independent predictor of AF recurrence (HR, 1.713; 95% CI, 1.02-2.90; P = 0.045). There were no differences in intra-procedure complications (2.2 vs. 5.6 vs. 4.9%, P = 0.542). The myocardial lesion according to TpnI was smaller in Group 2 (P = 0.02).
Conclusion: The cooled-tip catheter at 30 W was less efficacious than both the 8 mm catheter and the cooled-tip with a 40 W power setting.