Left atrial mechanical function following hybrid epicardial-endocardial vs endocardial catheter ablation: A...

Convergent hybrid ablation (HA) combines epicardial and endocardial approaches to achieve pulmonary vein isolation (PVI) and posterior wall isolation (PWI). Whether this strategy compromises left atrial (LA) mechanical function remains uncertain.

To compare the effects of HA and endocardial-only catheter ablation (CA) on LA mechanical function.

50 patients with persistent atrial fibrillation (AF) were randomized (1:1) to PVI and PWI via HA or CA. Blinded speckle-tracking echocardiography was performed at baseline and 6 months. Primary mechanistic analyses were prespecified to include patients in sinus rhythm at follow-up (n = 42) to enable comparable assessment of rhythm-dependent atrial mechanics. The primary endpoint was the between-group difference in post-ablation LA reservoir strain (LASr, %), adjusted for baseline values. Secondary endpoints included LA ejection fraction (LAEF, %) and LA volume index (LAVi, mL/m²). Between-group comparisons used baseline-adjusted analysis of covariance with supporting linear mixed-effects models.

Baseline characteristics were balanced (mean age: 69 ± 7.5 years; median AF duration: 26 months). At baseline, all patients were in AF with impaired LA function (LASr: 8.6 ± 3.8%, LAEF: 22.9% ± 7.5%, and LAVi: 50.7 ± 10.0 mL/m²; P > .05 between groups). At follow-up, 84% were in sinus rhythm (HA: 88%, CA: 80%; P = .70). LASr, LAEF, and LAVi significantly improved in both groups (all P < .001). No significant between-group differences were detected after baseline adjustment.

Among patients in sinus rhythm at follow-up, both HA and CA were associated with favorable LA remodeling. No signal of adverse LA remodeling or impaired LA mechanical recovery was observed with HA compared with CA, despite its dual epicardial-endocardial approach.