Efficacy of very high power short duration radiofrequency ablation in achieving acute pulmonary vein isolation: insight from a large multicenter study

Abstract Background The QDOT Micro catheter (Biosense Webster, Inc CA) enables the ablation in the Qmode+ modality (90 W for 4 sec) and/or in the Qmode modality, 50 W ablation index (AI)-guided. Both modalities of very high-power short duration (vHPSD) ablation have been described to improve procedural efficiency without compromising the efficacy and the safety of the pulmonary vein isolation (PVI). However, data from large multicentric registries are still lacking. Purpose We sought to investigate in a large cohort of atrial fibrillation (AF) patients the impact of different ablation strategies: the hybrid approach (Qmode+, 90 W for 4 sec, at the posterior wall of the left atrium and Qmode modality AI-guided at the anterior wall) vs. the ablation performed exclusively with the Qmode+ modality. Methods The AIR HPSD Registry is a multicentric study including AF patients undergoing their first PVI procedure by mean of the QDOT Micro catheter across 22 European centers. The ablation modality (hybrid/ Qmode+) was left to operators’ preference. Results Overall, 917 patients have been enrolled, 72% males, 70% had paroxysmal AF, the mean age was 62±10 years. Pulmonary vein isolation was reached in 100% regardless of the ablation modality. As for the first pass isolation (FPI), the rate was significantly higher in the hybrid group compared to the Qmode+ group (78% vs. 70%, p=0.01), even when considering the right (86% vs. 79%, p=0.01) and left veins (88% vs. 82%, p=0.02) separately. The fluoroscopy time was higher in the hybrid group (380±435 vs. 204±249 sec, p<0.001) however the procedural time was similar between the two groups (110±39 min vs. 95±38 min, p=ns). Furthermore, as expected, the saline infusion volume was higher in the hybrid group (410±274 vs 225±78 ml, p<0.001). No differences in the rate of complications were observed between the two groups (1,5% vs. 0,3%, p=ns). Conclusion The hybrid and the Qmode+ approaches are both highly effective and safe in achieving PVI, however the hybrid strategy significantly increases the rate of FPI without increasing the overall procedural time.