Abstract
Background
Proposed to facilitate pulmonary vein isolation (PVI), high-power ablation may cause extracardiac damage. This study evaluated the safety and efficacy of ablation index (AI) guided high-power ablation first in an animal model and subsequently in a clinical study.
Methods
Outcomes of radiofrequency (RF) applications were compared in a swine ventricular endocardial model (n = 10 each for 50W, 40W and 30W; AI = 500), and in 100 consecutive patients with paroxysmal atrial fibrillation undergoing PVI (40W [last n = 50] vs. 30 W [first n = 50]; target AI = 400/500 on posterior/anterior wall, respectively). Acute PV reconnection was assessed post adenosine administration 20 minutes after ablation.
Results
In swine ventricular endocardial RF applications, use of 50W and 40W vs. 30W was associated with greater tissue lesion depth (5.06 ± 0.16 and 4.38 ± 0.13 mm vs. 3.95 ± 0.16 mm; P < 0.001) and smaller lesion maximum diameter (7.81 ± 0.15 and 8.42 ± 0.18 mm vs. 9.08 ± 0.15 mm; P < 0.001). Tissue necrosis caused by 50W vs. 40W and 30W was the deepest and largest (3.15 ± 0.18 mm vs. 2.71 ± 0.17 and 2.42 ± 0.13 mm; and 5.58 ± 0.18 mm vs. 5.18 ± 0.16 and 3.94 ± 0.17 mm; respectively; P < 0.001). In PVI, use of 40W vs. 30W was associated with shorter procedure time (56.54 ± 1.81 min vs. 76.55 ± 2.34 min; p < 0.001) and ablation time (35.85 ± 14.87 min vs. 51.01 ± 17.99 min; p < 0.001); lower RF energy per point (909.02 ± 354.57J vs. 1045 ± 376.60J; p < 0.001); higher first-pass PVI (87% vs. 72%; P < 0.01); lower acute PV reconnection (22% vs. 41%; P < 0.01); no complications in either group; and similar sinus rhythm maintenance at 12 months (92% vs. 84%; P = 0.22).
Conclusions
AI-guided high-power (40W) vs. conventional (30W) PVI was related to a reduced time for procedure and was considered safe, with diminished acute pulmonary vein reconnection.
Acute pulmonary vein isolation lesions consist of interstitial oedema and tissue necrosis: possible mechanism of pulmonary vein reconnection
