Learning Curve of Pentaspline Pulsed-Field Ablation With Posterior Wall Isolation for Persistent Atrial Fibrillation.

BACKGROUND

Pentaspline pulsed-field ablation (PFA) has emerged as a novel modality for pulmonary vein isolation (PVI) and posterior wall isolation (PWI) in persistent atrial fibrillation (AF). However, the learning curve associated with combined PVI + PWI and the contribution of anatomical factors to acute lesion completeness remain incompletely defined.

METHODS

We analyzed 182 consecutive patients with persistent AF undergoing fluoroscopy- and intracardiac echocardiography-guided PFA. Acute incomplete lesions were defined as residual conduction requiring additional PFA applications after systematic remapping. Learning phases were identified using segmented logistic regression and sequential block analysis. Multivariable models evaluated procedural phase, left atrial volume (LAV), and posterior wall geometry.

RESULTS

A learning curve was observed, with the greatest reduction in incomplete lesion formation occurring during the first 20 procedures. Incomplete lesions occurred in 55% of cases 1-20 (early phase), 32% of cases 21-160 (intermediate phase), and 4.8% of cases ≥ 161 (late phase). Procedural phase was the dominant determinant of incomplete lesions, with approximately 24-fold and 9-fold higher odds during the early and intermediate phases, respectively. Larger LAV showed a modest independent association (OR 1.009 per mL), whereas posterior wall geometry was not independently associated. Mid-term arrhythmia recurrence did not differ across phases, although follow-up duration was shorter in the late phase.

CONCLUSIONS

Lesion completeness during pentaspline PFA with PVI + PWI improves progressively with increasing procedural experience. Although larger LAV may contribute modestly to incomplete lesion formation, procedural experience appears to play the predominant role. Systematic electroanatomical remapping remains important for identifying and correcting incomplete lesions even after substantial procedural experience has been accumulated.