# Comparison of 3C4L and 2C3L radiofrequency ablation strategies for persistent atrial fibrillation: procedural profile and 2-year outcomes

## TL;DR

This study compares two radiofrequency ablation strategies for treating persistent atrial fibrillation, finding that the more complex 3C4L approach improves heart function and long-term outcomes without increasing complications.

## Contribution

The study provides new evidence that the 3C4L ablation strategy offers better clinical outcomes than the 2C3L strategy for persistent atrial fibrillation.

## Key findings

- The 3C4L group had longer procedure times and higher X-ray exposure but no significant increase in complications.
- The 3C4L strategy showed better improvement in myocardial motion parameters and serum biomarkers post-treatment.
- At 24 months, the 3C4L group had significantly higher arrhythmia-free survival compared to the 2C3L group.

## Abstract

To investigate the effects of 3C4L vs. 2C3L radiofrequency ablation strategies on quantitative myocardial motion parameters and serum biomarkers in patients with persistent atrial fibrillation.

A retrospective study was conducted on 105 patients with persistent atrial fibrillation who underwent radiofrequency ablation treatment at our hospital between March 2023 and November 2024. All patients' data were obtained from the medical record system. Patients were divided into two groups based on the ablation strategy employed: a 2C3L group (n = 50, two circumferential lesions plus three linear lesions) and a 3C4L group (n = 55, three circumferential lesions plus four linear lesions). The choice of ablation strategy was determined by the treating physician based on atrial fibrillation characteristics, left atrial size, and institutional experience during the study period. Clinical baseline data, perioperative related indexes, quantitative myocardial exercise parameters, and serum biomarkers were compared between the two groups.

There was no statistically significant difference in circumferential pulmonary vein isolation ablation time, cavotricuspid isthmus ablation time, and left atrial apical line ablation time between the 3C4L group and the 2C3L group (P > 0.05). However, the 3C4L group had significantly longer total procedure time (172.06 ± 39.33 vs. 156.10 ± 36.37 min, P = 0.034), mitral isthmus ablation time (14.58 ± 2.78 vs. 10.21 ± 2.96 min, P < 0.001), X-ray exposure time (7.05 ± 1.87 vs. 2.60 ± 0.42 min, P < 0.001), and greater saline perfusion volume (1,197.43 ± 184.47 vs. 1,072.33 ± 57.42 mL, P < 0.001) compared to the 2C3L group. Before treatment, there were no significant differences between groups in quantitative myocardial motion parameters and serum biomarker indexes (P > 0.05). After treatment, the 3C4L group showed significantly better improvement in quantitative myocardial motion parameters and serum biomarker indexes compared to the 2C3L group (all P < 0.05). The total incidence rate of complications was not significantly different between the 3C4L group (20.00%, 11/55) and the 2C3L group (16.00%, 8/50) (χ2 = 0.575, P = 0.448). At 24 months, Kaplan–Meier analysis demonstrated significantly higher arrhythmia-free survival in the 3C4L group compared to the 2C3L group (50.0% vs. 30.0%, log-rank P = 0.018; hazard ratio 0.52, 95% confidence interval: 0.30–0.90).

Compared with the 2C3L radiofrequency ablation strategy, the 3C4L strategy, while requiring longer procedure time, does not significantly increase complication rates and demonstrates superior clinical efficacy with better improvement in cardiac function and long-term arrhythmia-free survival. These findings should be interpreted cautiously given the retrospective, non-randomized study design and require validation through prospective randomized controlled trials.