Focal lattice tip catheter toggling between pulsed field energy and radiofrequency vs. high power short duration for pulmonary vein isolation: a multicenter study

A novel focal 9mm lattice tip catheter, namely Sphere-9 (Affera Inc), has recently received regulatory approval and is part of a technology that allows the delivery of either pulsed electric field or radiofrequency energy and incorporates a proprietary 3D electroanatomical mapping system. Objective: to compare the acute procedural outcomes between focal 9-mm lattice tip catheter Sphere-9 (Affera Inc) and High-Power Short-Duration radiofrequency ablation (HPSD).

Consecutive AF patients undergoing first-time pulmonary vein isolation (PVI) with the Affera system or HPSD in six different centres between August and June 2024 were prospectively included. In the Sphere-9 arm PVI was performed with PFA on the posterior wall and anteriorly with radiofrequency or PFA at the operator's discretion. In the HPSD arm PVI was performed anteriorly with 50W /550 ablation index and posteriorly with 40W or 50W/ 400 ablation index. Primary endpoints were acute procedural success, PVI time and first pass isolation. Primary safety endpoint included major complications occurring within 7 days post-ablation.

240 patients (mean age: 65.9 ± 10.4 years; 64.4% males; 34.9% had non-paroxysmal AF) were enrolled (Sphere-9: 120 pts; HPSD: 120 pts). The primary efficacy endpoint was achieved in 100% of patients in both groups. Sphere-9 significantly reduced PVI time compared to HPSD ( 25 min vs 31 min; p=0.003). Sphere-9 demonstrated a significantly higher rate of first pass isolation than HPSD (90.8% vs 67.1%; p<0.0001) (Figure 1). No differences were reported for major complications (0% vs 0.8%; p=0.31) and overall complications between Sphere-9 and HPSD (0% vs 1.7%; p=0.16). Sphere-9 significantly reduced procedural time (60 min vs 88 min; p<0.001), dwelling time (41 min vs 66 min; p<0.001) and fluoroscopy time ( 4 min vs 6 min; p=0.04) compared to HPSD.

Sphere-9 proved to significantly reduce PVI, procedure, dwelling and fluoroscopy time compared to HPSD ensuring a higher rate of first pass isolation.