High-Power (40-50 W) Radiofrequency Ablation Guided by Unipolar Signal Modification for Pulmonary Vein Isolation: Experimental Findings and Clinical Results

Background: Although proposed to facilitate pulmonary vein isolation (PVI), high-power ablation may favor extracardiac damage. Negative component abolition of the unipolar signal reflects lesion transmurality. The present study sought to evaluate the safety and efficacy of high-power ablation using unipolar signal modification as a local end point. Methods: High power and standard power were compared in 4 swine and 100 consecutive patients referred for PVI. The first 50 patients were included in the control group (25-30 W) and the last 50 patients in the study group (40-50 W). Atrial radiofrequency applications were stopped 2 s (study group and swine) or 5 s (control group) after unipolar signal modification. Ventricular radiofrequency applications of 500 J (25 W20 s versus 50 W10 s) were performed at the swine epicardium. Results: Swine gross necropsy did not show any extracardiac damage related to atrial lesions. At equal energy of 500 J, 50 W lesions were deeper (30.9 versus 2.6 +/- 1.1 mm; P=0.03) and wider (6.2 +/- 2 versus 5 +/- 2.3 mm; P=0.006) than 25 W lesions. No complications occurred during the clinical study, whatever the power output used for PVI. For a similar sinus rhythm maintenance at 12 months (90% versus 88%; P=0.75), the study group displayed higher first-pass PVI (92% versus 73%; P<0.001), lower acute pulmonary vein reconnection (2% versus 17%; P<0.001), reduced procedure time (73.1 +/- 18.2 versus 107.4 +/- 21.2 min; P<0.001), and ablation time (13 +/- 2.9 versus 30.3 +/- 8.8 min; P<0.001). Conclusions: High-power PVI guided by unipolar signal modification safely decreases procedural burden while ensuring robust 12-month outcomes.