Background

Feasibility and efficacy of high power short duration (HPSD) catheter ablation (CA) for pulmonary vein isolation (PVI) in patients (pts) with atrial fibrillation (AF) has been proven in clinical trials. However, feasibility and outcome data using HPSD for substrate modification (defragmentation, lines) beyond PVI in patients with recurrence of persistent AF (persAF) is sparse.

Objective

We sought to report, for the first time, data on feasibility and success rates using HPSD in pts with recurrence of persAF after previous PVI.

Methods

Repeat CA for recurrence of persAF using HPSD was compared to conventional contact force radiofrequency CA (cRF [30-40W/120s]). A power setting of 70W/7s (70W/5s at posterior wall) was considered as HPSD. Ablation extent was at operators’ discretion for both groups. Lines were evaluated by pacing maneuver and activation/voltage mapping. Follow-up consisted of out-clinic visit, tele-consultation, 48h holter ECG and CIED interrogation if applicable.

Results

A total of 387 pts underwent CA for recurrence of persAF after PVI (33 [8.5%] pts HPSD vs. 354 [91.5%] cRF) between 01/2018 and 09/2021. There was a comparable number of patients with > 1 previous PVI in both groups (HPSD 13 [39%] and cRF 134 [38%] (p=0.853). Left atrial (LA) defragmentation ablation and the following line sets were achieved using HPSD in comparison to cRF: LA roof line (18 [55%] HPSD and 148 [43%] cRF pts; p=0.199); posterior wall isolation (9 [27%] HPSD vs. 144 [41%] cRF pts; p=0.142); LA defragmentation and anterior line (19 [58%] HPSD vs. 94 [27%] cRF pts; p=0.005). Due to the shallow lesion formation in HPSD no mitral isthmus line was performed using HPSD. For HPSD a shorter procedure duration was seen without reaching statistical significance (151±52min in HPSD vs. 186±169min in cRF; p=0.237). Fluoroscopy duration and dosage was significantly elevated for HPSD (23±10min vs. 18±11min in cRF; p=0.012 and 6648±3710 mGy*cm² vs. 4890±4562 mGy*cm² in cRF; p=0.032). Two HPSD pts [6%] suffered complications (1 pneumonia due to aspiration, 1 tamponade and sinus arrest receiving a pacemaker). In the cRF group complication rate was comparable (21 pts [6%]; p=1) [5 groin bleedings, 3 tamponades, 3 TIAs, 10 pneumonias].

At a follow-up of 289±150 days the arrhythmia free survival rate was similar in both groups (26 [79%] HPSD vs. 252 [71%] cRF pts; p=0.42).

Conclusion

In this cohort of 387 pts undergoing repeat CA for recurrence of persAF a HPSD ablation approach seems to be equally safe and effective compared to conventional RF ablation with comparable arrhythmia free survival rates. Of note, creation of LA lines is equally feasible using HPSD.