Background
Radiofrequency (RF) high‐power ablation appears to be a novel concept in treating atrial fibrillation (AF). The ablation‐index (AI) has been linked with the durability of pulmonary vein isolation (PVI). To report the midterm clinical results of a new ablation strategy using AI‐guided high‐power (50 W) ablation (AI‐HP).
Methods and Results
Symptomatic AF patients were included and underwent wide‐area circumferential PVI. Contact‐force catheters were used, RF power was set to 50 W targeting AI values (550/400 for anterior/posterior) and interlesion distance 6 mm. Luminal esophageal temperature (LET) was monitored during the procedure; patients with LET ≥39°C underwent post‐ablation esophageal‐endoscopy. Seventy‐two‐hour‐Holter ECGs were scheduled during follow‐up. Procedural PVI was achieved in all (N = 122; mean age, 68.2 years; male, 71.3%) patients, rate of first‐pass PVI was 96.7% per patient. Procedural mean RF time was 11.5 min, and mean RF time during posterior wall segment was 3.1 min. Per RF‐lesion, the mean contact force, RF duration, AI, and impedance‐drop at anterior/posterior wall were 26 ± 14 g/23 ± 12 g, 16.2 ± 7.5 s/8.8 ± 3.6 s, 552 ± 53/438 ± 47, and 13 ± 6 Ω/9 ± 5 Ω, respectively. Mean PVI procedural‐time, 55.8 min; mean procedural fluoroscopic time, 5.6 min. Three (2.5%) patients had asymptomatic endoscopic small erosion/erythema esophageal lesions, no serious adverse events were observed. During a 15‐month follow‐up, overall single‐procedure freedom from clinical recurrence of AF/atrial tachycardia (AT) off antiarrhythmic drug after blanking period was 85.2% (89.4% for paroxysmal AF, 80.4% for persistent AF).
Conclusion
The AI‐HP (50 W) appears as an efficient ablation technique in treating AF and leads to a high single‐procedure arrhythmia‐free survival at 15 months.