Background: High-power short-duration (HP-SD) radiofrequency (RF) ablation strategies have been developed in effort to reduce the effect of catheter instability and tissue edema inherent to moderate power and moderate duration (MP-MD) ablation. However, the effect of HP-SD ablation strategy on long-term pulmonary vein isolation (PVI) durability is unknown.
Objective: To compare the durability of PVI between HP-SD and MP-MD RF ablation strategies.
Methods: In this prospective, controlled single center study, 112 patients with paroxysmal or persistent AF underwent first-time PVI using HP-SD ablation strategy: 40-50W (15 seconds anterior wall, 8 seconds posterior wall) using Carto 3^® and Thermocool ST-SF™ catheter (Biosense Webster). The control group consisted of 112 patients who underwent PVI using MP-MD ablation strategy (30-40W/30 seconds anterior wall, 20W/20 seconds posterior wall) with a similar technology. Acute PV reconnection was examined using adenosine or isoproterenol and chronic PV reconnection was examined in patients with recurrent atrial arrhythmias who required a redo procedure. Safety endpoints included development of atrio-esophageal fistula, pericardial effusion, tamponade, phrenic nerve paralysis and stroke.
Results: PVI at the completion of the initial encirclement was higher with HP-SD ablation (90.2% vs 83.0%; P=0.026). The mean delivered power was also higher (45.6±2.4 vs 32.4±5.5; P<0.001) and the mean RF ablation time was shorter (17.2±3.4 min vs 31.1±5.6 min; P<0.001). The incidence of acute PV reconnection was lower with HP-SD (6.2% vs 12.5%; P=0.023). 18 patients in the HP-SD group and 23 in the MP-MD group underwent a redo procedure 1.0±0.6 years after the initial PVI. The incidence of chronic PV reconnection was lower in the HP-SD group (16.6% vs 65.2%; P=0.019). Maximal esophageal temperature rise was higher with HP-SD ablation (39.2±2.2 vs 38.1 ±1.1; P=0.032). There were no atrio-esophageal fistulas, pericardial effusions or strokes in any of the groups. One patient in the MD-MD ablation group developed phrenic nerve paralysis.
Conclusion: HP-SD ablation strategy results in improved PVI durability, shorter ablation time and comparable safety profile to conventional MP-MD ablation.