Efficacy of Additional Extra Mapping-Guided Substrate Ablation Beyond Pulmonary Vein Isolation in Persistent Atrial Fibrillation: The Rotate Trial.

Introduction: There are currently no established effective additional substrate ablation strategies beyond pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF).

Objective: This randomized clinical trial evaluated the efficacy of a novel substrate ablation technique using the ExTRa Mapping system, which visualizes rotational activation during AF rhythm.

Methods: This study included 80 patients undergoing initial catheter ablation for persistent AF. Eighty patients whose AF persisted after PVI and ExTRa Mapping were randomly assigned in a 1:1 ratio to either PVI alone or PVI plus ExTRa Mapping-guided substrate ablation targeting areas with high non-passively activated ratio(%NP)( ≥ 35%)(ExTRa group). The primary outcome measure was recurrence of atrial tachyarrhythmias after a 90-day blanking period postablation.

Results: Post-PVI ExTRa Mapping assessed a median of 36 sites per patient in both atria. Baseline characteristics were comparable between groups. The ExTRa group showed higher event-free survival from the primary outcome compared to the PVI alone group (85.0% vs. 67.5% at 1-year, p = 0.07). This favorable prognosis was more pronounced for patients with a large( ≥ 12 sites) area of rotational activation area (81.0% vs. 57.9% at 1-year, p = 0.01). Multivariable analysis identified the number of high %NP areas as an independent risk factor for recurrent tachyarrhythmias (HR 1.13, 95%CI 1.03-1.23, p = 0.005), while ExTRa Mapping-guided substrate ablation emerged as a unique protective factor (HR 0.38, 95%CI 0.13-0.99, p = 0.047).

Conclusion: While the reduction in atrial tachyarrhythmia recurrence of persistent AF patients did not reach statistical significance, the addition of ExTRa Mapping™-guided substrate ablation beyond PVI demonstrated promising potential, especially in patients with larger rotational activation areas.