Procedural and clinical outcomes of very high-power short-duration versus ablation index-guided pulmonary vein isolation -The Q-POWER Study -
N Van Pouderoijen, M J Mulder, L H G A Hopman, L E Wentrup, J R De Groot, P G Postema, H A Hauer, M J W Gotte, M J B Kemme, C P AllaartAbstract
Background
Several ablation strategies are available to achieve pulmonary vein isolation (PVI). PVI performed exclusively with very high-power short-duration (vHPSD) radiofrequency (RF) ablation may enhance procedural efficiency compared with conventional ablation-index (AI) (force-power-time)-guided approaches.
Purpose
To evaluate procedural efficiency and one-year clinical outcomes of PVI performed exclusively with vHPSD compared with AI-guided ablation in patients with atrial fibrillation (AF).
Methods
A total of 85 patients with paroxysmal or persistent AF referred for primary RF PVI were prospectively included. The AI group (n=45), derived from the OPTIGRID Study (2018-2019), underwent PVI using a SmartTouch catheter at 30/40W, with AI targets of 380 and 500 for posterior/inferior and anterior/roof segments, and inter-lesion distance (ILD) <6 mm. The vHPSD group (n=40), derived from the Q-POWER Study (2023-2024), underwent PVI with the QDOT MICRO catheter using solely 90W/4s and ILD <4 mm and partly <6 mm (posterior wall). If first pass isolation was not achieved after initial vHPSD encirclement, touch-up ablation was performed using AI guided ablation ≤50W. In both groups, PVI was confirmed by entry and exit block after a waiting period of 30 min. If acute reconnection occurred, further ablation was performed until re-isolation. One-year recurrence of atrial tachyarrhythmias, defined as any atrial tachyarrhythmia lasting >30 seconds, was monitored through electrocardiograms, Kardia recordings, and 24-hour Holter monitoring at 3 and 12 months.
Results
Patients in the vHPSD group were younger compared to the AI patients (61±8 vs. 65±7 years, p=0.01), other baseline characteristics were similar. Procedure and RF times were significantly lower using vHPSD compared to AI-guided PVI (58.0±29.7 min vs. 72.4±25.9 min, p=0.02; 8.3±3.0 min vs. 37.1±7.6 min, p<0.001, respectively). Rates of first-pass isolation of the left and right pulmonary veins (PVs) were similar between vHPSD and AI-guided approaches (left PVs 55.0% vs. 62.2%, p=0.50; right PVs 45.0% vs. 62.2%, p=0.11, respectively). However, acute reconnection of the left PVs occurred significantly more in the vHPSD group, with a trend towards higher reconnection rates of the right PVs (35.0% vs. 15.9%, p=0.04; 30.0% vs. 13.6%, p=0.07, respectively). All patients completed 12 months follow-up. Recurrence of atrial tachyarrhythmias was not significantly different: 16 vHPSD-patients (40%) versus 19 AI-patients (42.2%) (log-rank test p=0.90).
Conclusion
PVI performed exclusively with vHPSD ablation was associated with shorter procedure and RF application times but with higher acute PV reconnection rates compared with conventional AI-guided ablation, raising concerns about the consistency of achieving transmural lesions with vHPSD. However, despite procedural differences one-year atrial tachyarrhythmia recurrence was similar, with clinical outcomes remaining comparable between groups.