Impact of linear ablation in persistent atrial fibrillation using a dual-energy, wide-footprint catheter: Analysis...

Among patients with persistent atrial fibrillation, linear ablation lesions beyond pulmonary vein isolation (PVI) are often performed with variable efficacy and inconsistent added value. New catheter designs and energy sources have the potential to improve outcomes.

This study aimed to examine (1) the performance of a novel dual-energy (pulsed field/radiofrequency) lattice-tip mapping and ablation system for linear ablation and (2) the impact of the ablation strategy on outcomes in the randomized SPHERE Per-AF trial.

Linear lesion characteristics, safety, and effectiveness were assessed for a conventional radiofrequency ablation system in the control arm vs the dual-energy lattice-tip system in the investigational arm.

In the investigational arm, 203 patients (95.8%) received left atrial roof and/or posterior wall isolation, 117 (55.2%) cavotricuspid isthmus line, and 76 (35.8%) mitral line. In the control arm, 102 patients (68.9%) received left atrial roof and/or posterior wall isolation, 76 (51.4%) cavotricuspid isthmus line, and 19 (12.8%) mitral line. Transpired ablation and energy application times were shorter for each lesion type using the investigational than the control catheter (all P < .0001). Overall, there was a trend toward numerically higher 12-month effectiveness of a "PVI + all linear lesions combined" approach (n = 25) than a PVI-only ablation strategy (n = 56) (P = .07), and the effect was more pronounced in the investigational arm, but subgroups were small.

There was a trend toward numerically higher effectiveness with linear lesions than PVI alone. These findings are exploratory and hypothesis generating and should prompt future randomized controlled trials of additional lesion sets vs PVI with this new technology.

NCT05120193 - Treatment of Persistent Atrial Fibrillation with Sphere-9 and Affera Mapping and Ablation System (SPHERE Per-AF).