Procedural characteristics of very high-power short-duration compared to ablation index-guided ablation for pulmonary vein isolation in atrial fibrillation patients

Abstract Background Very high-power short-duration (vHPSD) radiofrequency (RF) ablation may reduce procedure time compared to conventional ablation-index (AI) guided pulmonary vein isolation (PVI) while ensuring continuous, transmural lesions. Purpose To study the effect of vHPSD ablation on PVI procedural characteristics compared to conventional AI-guided ablation. Methods A total of 86 patients with paroxysmal or persistent AF referred for primary RF PVI were included. The AI group (n=45), from the OPTIGRID Study (2018-2019), underwent PVI using a SmartTouch catheter at 40/30W and inter tag distance (ITD) <6 mm. The vHPSD group (n=41), from the Q-POWER Study (2023-2024), underwent PVI with the QDOT MICRO™ catheter using 90W/4s and ITD <4 mm and partly <6 mm for the posterior wall. Touch-up ablation was performed using ≤50W. In both groups, PVI was confirmed by conduction block during a waiting period of 30 min. If reconnection occurred, further ablation was performed until re-isolation. Results Baseline characteristics were similar, except for a younger age in the vHPSD group (61±8 vs. 70±7 years, p<0.001). Procedure and RF times were significantly lower using vHPSD compared to AI-guided PVI (57.7±29.4 vs. 72.4±25.9min, p=0.02; 8.3±3.0 vs. 37.1±7.6min, p<0.001, respectively). Trends were observed in lower first pass isolation (FPI) rates of the right PVs in the vHPSD group (43.9% vs. 62.2%, p=0.09), as well as higher reconnection rates of both left and right PVs compared to the AI group (34.1% vs. 15.9%, p=0.05; 29.3% vs. 13.6%, p=0.08, respectively). Conclusion Although PVI using solely vHPSD ablation results in reduced procedure and RF times, it showed lower rate of FPI and higher reconnection rates compared to conventional AI-guided ablation. This may question the ability of vHPSD to achieve transmural lesions in all PV segments. Long-term follow-up is needed to determine durability of PVI and differences in AF recurrence with both ablation techniques.