Pulmonary vein reconnections at time of repeat procedure, variations by ablation modality

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, linked to high morbidity, including stroke, heart failure, and mortality. Catheter ablation (CA) for pulmonary vein isolation (PVI) has become a primary therapy for patients with symptomatic, drug-resistant AF. Though CA primarily provides symptom relief and rhythm control rather than a cure, repeat procedures are often necessary due to AF recurrence. This study evaluates differences in pulmonary vein reconnection rates and patterns between pulsed field ablation (PFA) and radiofrequency ablation (RFA) in an effort to improve procedural efficacy and long-term outcomes by better understanding the factors which contribute to durable PVI.

This single-centre, retrospective cohort study evaluated pulmonary vein (PV) reconnections during repeat ablation procedures. Sequential cases of first repeated AF ablation procedures were categorized based on their initial ablation modality, extracted from the MPN AF Registry from April 2022, with a target of 50 cases per cohort (MMUH/MPH IRB Ethics Approval Reference 1/378/2283). Patient demographics, clinical characteristics, and procedural details were collected from the registry. PV reconnection patterns were obtained through procedural reports and related correspondence.

The study included 44 RFA cases and 62 PFA cases. No significant differences were noted in age, gender, CHADSVASc score, left atrial (LA) dilatation, or AF type between the cohorts, although persistent AF was more prevalent in the PFA group (69%) than the RFA group (50%).

On PVI durability, 70% of PVs remained isolated in the PFA group compared to 66% in the RFA group. The left superior PV (LSPV) (35.5%) was the most reconnected in the PFA group, while the right superior PV (RSPV) (36.4%) was most reconnected in the RFA group. Five patients in the PFA group and six in the RFA group exhibited common left ostia, all of which remained isolated at repeat ablation.

Reconnection rates in the inferior veins were similar across ablation modalities, with right inferior PV (RIPV) reconnections in 30.6% of PFA cases and 31.8% of RFA cases and left inferior PV (LIPV) reconnections at 29% and 29.5%, respectively. Durable PVI was achieved in 27% of PFA cases versus 43% for RFA. Single PV reconnections were more frequent in PFA cases, while paired reconnections predominated in RFA.

In 62 PFA and 44 RFA repeat ablation cases, 70% and 66% of PVs remained isolated respectively, with durable PVI in 27% of PFA and 43% of RFA cases. The differing reconnection patterns, notably in left superior and right superior PVs, underscore the potential to refine ablation techniques to enhance PVI durability and reduce AF recurrence and consequentially improve long patient outcomes.

PV Reconnection rates, PFA vs RFA