Insights from optimal high-power ablation settings for anterior pulmonary vein wall isolation-A-Q-RATE POWER Trial

The radiofrequency (RF) lesions obtained using very high-power short-duration (vHPSD) are shallower compared to high-power sort-duration (HPSD) or conventional ablation settings. Thus, there is a possibility that vHPSD RF applications may not achieve transmurality at thick parts of the anterior aspects of the pulmonary vein (PV)-left atrial (LA) wall junction. The aim of the study was to compare acute efficacy of pulmonary vein isolation (PVI) using vHPSD versus HPSD guided by AI ablation at the anterior aspects of PV in patients undergoing atrial fibrillation (AF) ablation.

The A-Q-RATE POWER Trial was a prospective, dual-center, randomized study. Patients were assigned to receive vHPSD versus HPSD ablation delivered at the anterior aspects of PV. In both arms, the posterior parts of PV were ablated with vHPSD. The primary outcome was the need for additional RF applications at the anterior aspect of PVs to achieve complete PVI.

Seventy patients were randomly assigned to vHPSD (n = 35) or HPSD (n = 35). The vHPSD group required more touch-up RF applications at the anterior aspects of PV than the HPSD group (46% vs 19%, p < 0.001), especially at the right PVs (57% vs 20%, p = 0.001) compared to the left PVs (34% vs 17%, p = 0.1). The median duration of the procedure, LA dwell time, and fluoroscopy time were similar in both groups (112 [IQR 90-130] min vs 107 [90-125] min, p = 0.58; 95 [70-106] min vs 90 [71-100] min, p = 0.55; and 28 [IQR 14-69] s vs 46 [IQR 0-89] s, p = 0.97,respectively).

The proposed hybrid strategy is associated with a significantly lower need for additional touch-up RF applications than vHPSD only, without extending procedural and fluoroscopy duration.