Kim, James

Background: Pulsed Field Ablation (PFA) has gained widespread adoption for pulmonary vein isolation (PVI) due to its tissue selectivity and safety profile. However, its role in cavotricuspid isthmus (CTI) ablation for typical atrial flutter is less defined. This study compares CTI ablation using PFA versus radiofrequency ablation (RFA) in patients undergoing PVI exclusively with PFA. Research Question: We hypothesized that in patients undergoing PFA-based PVI, CTI ablation using PFA would reduce procedure and fluoroscopy times without increasing complication or flutter recurrence rates compared to RFA. Methods: We retrospectively analyzed patients who underwent CTI ablation with either PFA or RFA alongside PFA PVI between 2024 – 2025 across all Mayo Clinic sites. Baseline characteristics, procedural parameters, acute success, and 12-month arrhythmia recurrence were compared between groups. All patients received standard follow-up, including ECGs and Holter monitoring. Results: A total of 350 patients were included (CTI PFA: n = 126; CTI RFA: n = 224). Patients in the PFA group were older (68.8 ± 8.5 vs. 65.7 ± 10.1 years; p <0.01) and had higher CHA2DS2-VASc scores (2.84 ± 1.57 vs. 2.45 ± 1.45; p = 0.02). Fluoroscopy (18.9 ± 9.1 vs. 25.2 ± 23.3 min; p < 0.01 ) and procedure times (172.6 ± 22.4 vs. 224.7 ± 74.2 min; p < 0.01) were significantly lower in the PFA group. Complication rates (8.7% vs. 4.9%; p = 0.15) and typical flutter recurrence (3.1% vs. 1.7%; p = 0.46) were similar between groups during a mean follow-up of 125 days. Conclusion: In patients undergoing PVI with PFA, CTI ablation using PFA is associated with significantly reduced procedure and fluoroscopy times compared to RFA, without increased complications or arrhythmia recurrence. These findings support the feasibility and efficiency of PFA for typical flutter ablation when performed during PFA-based AF procedures.

Background: A blanking period allowing for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has historically been standardized to 90 days. With the recent introduction of pulsed field ablation (PFA) for PVI and emerging in vitro data suggesting a shorter inflammatory timeframe, it remains unclear whether recurrences during this 90-days period reflect incomplete procedural success or merely transient inflammatory changes. Research Question: In patients undergoing PVI with PFA, do early AF recurrences at 30, 60, and 90 days predict late AF recurrences beyond the standardized 90-day blanking period? Methods: Patients undergoing PFA for AF were retrospectively included. Procedures were performed under general anesthesia, and high-density (HD) mapping, with PVI and additional ablation lines applied at the operator’s discretion. PFA catheters included Farawave, PulseSelect, and Sphere-9. AF recurrences were defined as documented episodes on 12-lead ECG or cardiac monitoring devices, confirmed by interpretation from an experienced cardiologist. Survival analyses were conducted based on the occurrence of early recurrences at 30, 60, and 90 days post-ablation. Kaplan-Meier curves and hazard ratios were reported. This study was approved by our institutional review board. Results: To the best of our knowledge, this is the largest real-world study reporting outcomes of PFA for AF in the United States. A total of 1,214 patients were included in the analysis. Mean age was 66.4 years; 31.9% were female, and 22.4% underwent redo PVI. Six-month AF recurrence-free survival was 79% (95% CI, 75–83%) for the overall cohort. Patients experiencing early recurrence at 30, 60, and 90 days had a significantly higher risk of AF recurrence beyond the standardized 90-day blanking period (HR 4.0, 95% CI 2.7–5.9, P < 0.01; HR 5.0, 95% CI 3.6–7.1, P < 0.01; and HR 6.9, 95% CI 4.9–9.6, P < 0.01, respectively). Conclusion: Early recurrences at 30, 60, and 90 days post-ablation are strongly associated with atrial fibrillation recurrence beyond the 90-day blanking period. These findings challenge the traditional concept of blanking period after PFA and suggest that early recurrence may indicate incomplete procedural success rather than transient inflammation.