Pulsed-field ablation using a circular multielectrode catheter for persistent atrial fibrillation: procedural outcomes and lesion durability

Background

Pulsed-field ablation (PFA) is a novel non-thermal ablation technique that selectively targets myocardial tissue while sparing adjacent structures, potentially reducing complications associated with conventional thermal ablation. Clinical data on PFA for persistent AF (PsAF) remain limited.

Purpose

This study aimed to evaluate the procedural safety, acute efficacy, and lesion durability of PFA using a circular multielectrode array catheter in patients with PsAF.

Methods

We enrolled 158 consecutive PsAF patients (68 ± 12 years, 45 female) undergoing first-time pulmonary vein isolation (PVI) with a circular multielectrode array catheter (Pulse Select). All procedures were performed under deep sedation. After PVI, additional ablation—including left atrial posterior wall isolation (PWI), superior vena cava isolation (SVCI), and cavotricuspid isthmus (CTI) ablation—was performed as clinically indicated.

For linear lesions such as PWI and CTI, only the four distal electrodes were advanced beyond the sheath to maintain a straight and stable trajectory. Intracardiac echocardiography guided positioning, and bidirectional block was confirmed for all linear lesions. Procedures were approved by the institutional ethics committee, and informed consent was obtained. Periprocedural data, including the number of ablation applications, procedure and fluoroscopy times, and complications, were collected. Patients were followed prospectively with 12-lead ECG at three-month intervals and one-week Holter monitoring.

Results

All targeted lesions were successfully isolated. PWI was performed in 87% of patients, SVCI in 41%, and CTI ablation in 91%. Mean PFA applications were 43 ± 6 for PVI, 12 ± 4 for PWI, 6 ± 4 for CTI, and 2 ± 1 for SVCI. Mean procedure and fluoroscopy times were 82 ± 21 minutes and 24 ± 12 minutes, respectively. No major periprocedural complications, including phrenic nerve palsy or coronary spasm, were observed.

During a mean follow-up of 7.6 ± 2.8 months, arrhythmia recurrence occurred in 27% (43/158) of patients, including AF in 67% and atrial tachycardia in 33%. Nine patients who initially underwent CTI ablation experienced recurrence of CTI-dependent atrial flutter. Among 20 patients undergoing repeat ablation, durable isolation was observed in 45% for PVI (9/20), 10% for PWI (2/20), 60% for SVCI (3/5), and 17% for CTI (3/18), indicating lower durability of non-PV linear lesions.

Conclusions

PFA using a circular multielectrode catheter is safe and efficient for PsAF, achieving high acute success without major complications. However, non-PV linear lesions, including PWI, SVCI, and CTI ablation, show limited durability. Further long-term studies are needed to optimize lesion strategies and improve clinical outcomes.