Electrophysiological findings, incidence, and predictors for AF recurrence after pulsed field versus radiofrequency pulmonary vein isolation. A retrospective analysis

Abstract Background Pulsed field ablation (PFA) is an emerging method for catheter ablation of atrial fibrillation (AF). Data comparing efficacy and safety of PFA compared to thermal ablation is still scarce. In this study, we compared a cohort of patients who underwent PFA with those who received very high power short duration (vHPSD) radiofrequency catheter ablation at the University Hospital Graz. Methods We analysed baseline data from both cohorts (PFA: n=231; RF: n=243). Both procedures were performed under deep sedation, using propofol and fentanyl. The PFA procedure involved 2x2x2 pulses, with additional pulses as required. RF procedures were performed using the QDOT Micro catheter to deliver 90 watts of energy over 4 seconds. Statistical analysis was performed using IBM SPSS Statistics for Windows, version 29. The Kruskal-Wallis test was used for quantitative non-parametric data in the baseline analysis, and the Man-Whitney-U test was used for quantitative non-parametric procedural data. For qualitative variables the Chi-squared test was used. A p-value of less than 0,05 was considered significant. Results Both groups were similar, apart from chronic heart failure, which was more prevalent in the RF group (p=0.003). Mean age for both groups was 62±10 years and mean body mass index did not differ as well. CHADS-VASc score was 2±2 in the RF and 2±1 in the PFA group (p=0.7). The types of AF were distributed as follows: (RF vs.PFA): PAF: 64%/61%; persAF: 34/36%; long standing persAF: 2%/3%. As to this date performing a CTI line with PFA is off-label, a significantly higher number of patients with additional flutter were ablated in the RF group. In the RF-group, 91 patients underwent additional cavotricuspid isthmus ablation, compared to only 14 patients in the PFA group (p0.001). Procedural time (RF:PFA 122±min:57±26min; p0.001), fluoroscopy time (RF:PFA 15±9min:19±9min; p0.001) and fluoroscopy dose (RF:PFA 17±40Gycm2:15±15Gycm2, p=0.026) showed significant differences, with procedural time and fluoroscopy dose presenting lower values in the PFA group. First pass isolation was achieved more frequently in the PFA group (85% vs. 57%; p0,001). There was significant difference in recurrence rates between the vHPSD and PFA groups (RF: 56/242 (28%), PFA: 38/231 (17%); p=0.005). Additionally, time to recurrence in the RF group was 138±117 days, compared to 166±84min in the PFA group. We exclude operator dependence as the same operators performed both procedures. Conclusion Based on our findings, PFA could potentially become the standard procedure for many patients. However, randomized trials are needed to confirm these findings.