Background: Catheter ablation for atrial fibrillation (AF) treatment provides effective and durable pulmonary vein isolation (PVI) and is associated with encouraging clinical outcome. A novel open-irrigated contact force sensing temperature-controlled radiofrequency (RF) ablation catheter allows for very high-power short-duration (vHP-SD, 90W/4 seconds) ablation aiming a potentially safer, more effective and faster ablation. The catheter also allows for conventional temperature-controlled ablation (maximal 50W). Utilizing conventional point-by-point RF ablation the “close – protocol” with an inter-lesion distance (ILD) of 6mm has been introduced and verified. Since the lesion formation of vHP-SD ablation creates wider but shallower lesions we adapted the close-protocol to an individualized and tighter “very close-protocol” of 3-4mm ILD at the anterior aspect and 5-6mm at the posterior aspect of the left atrium using vHP-SD only. Here we thought to evaluate safety, efficacy and follow-up of vHP-SD ablation for PVI utilizing a novel vHP-SD catheter utilizing a very close protocol.

Methods and Results:

A total of 27 consecutive patients with symptomatic, drug-refractory PAF (13/27, 48%) or short-standing PersAF (14/27, 52%) presented for PVI only and were treated with a very-close protocol utilizing vHP-SD (90W / 4s). An esophageal temperature probe was utilized in all cases. The Teso (esophageal temperature) cut of was 41.5°C. All PVs were successfully isolated solely using vHP-SD (108/108, 100%). The median number of vHP-SD applications was 86 (interquartile range (IQR) 72, 98) and median RF ablation time was 350 (IQR 322, 440) seconds and the median procedure duration was 54 (IQR 51-60) minutes. The median left atrial dwelling time was 44 (IQR 34-47) minutes. First pass isolation for right PVs was achieved in 25/27 PVs (93%) and for left PVs in 23/27 PVs (85%). A Teso rise >41.5° was observed in 10/27 patients (37%) with a median Teso of 41.8 (IQR 40.4, 42.9) °C. No clinically relevant esophageal injury was reported. No pericardial effusion, tamponade, stroke or atrio-esophageal fistula occurred. A total of 3 patients (11.1%) reported on hematoma of the venous puncture site. After a median follow-up of 12 (IQR 12, 12) months 23/27 patients (85%) showed stable sinus rhythm.

Conclusions: This data of the very-close protocol solely utilizing vHP-SD ablation provides safe and effective PVI with a high rate of first-pass isolations. No severe periprocedural complications occurred and the procedure duration and RF ablation time were remarkable short. The one-year follow-up shows promising data and is comparable to the data of recent single-shot catheter ablation procedures.