1Herz- und Diabeteszentrum NRW Klinik für Elektrophysiologie/ Rhythmologie Bad Oeynhausen, Deutschland; 2GZO Spital Wetzikon Klinik für Kardiologie und Angiologie Wetzikon, Schweiz
Background
Pulsed field ablation (PFA) has recently been introduced as a novel single-shot ablation technology for catheter based pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Previously published studies have demonstrated high rates of acute success of PVI during PFA following a fluoroscopy-based approach where assessment of the acute ablation result relies on local electrogram information of the PFA device only. It remains unclear whether additional 3D-remapping after PFA could potentially detect incomplete ablation despite successful elimination of all local PV signals on the catheter device during ablation.
Methods
Consecutive patients with AF undergoing first time PVI by PFA between 08/2021 and 08/2023 were prospectively enrolled. Ablation was performed using a commercially available PFA system with seamless changing between a “flower-like” and a “basket-like” pose. Venous access was achieved by ultrasound-guided femoral puncture inserting two venous sheaths. A diagnostic coronary sinus catheter was placed. Transseptal puncture was performed using a modified Brockenbrough technique with 8.5 F transseptal sheaths and a BRK-1 XS needle. Selective angiographies and electroanatomic mapping using a 3D-system and a spiral mapping catheter were performed in each patient before PFA. The PFA delivery sheath was then inserted into the left atrium. The general ablation protocol provided 8 PFA impulses for each pulmonary vein (PV) with 4 impulses in the basket-like shape of the device and 4 impulses in the flower-like shape. In cases of failed acute PV isolation another complete cycle of 8 impulses per vein was delivered until all local PV signals on the catheter device could be eliminated. A repeat electroanatomic map in sinus rhythm was conducted in all patients. The procedural endpoint was complete PVI with demonstration of entrance and exit block of all PVs. In cases of detected incomplete PVI despite local elimination of all PV signals during PFA, the device catheter was re-introduced and repeat PFA was performed.
Results
A total of 251 patients (74.9% males) were included. Mean age was 63.4±10.9 years. Paroxysmal AF was present in 131 patients (52.2%). Mean left ventricular ejection fraction was 55.9±8.2% and mean left atrial volume index 39.1±18.2ml/m². Mean procedural duration was 55.6±4.9 minutes with a mean fluoroscopy time of 7.9±5.1 minutes. Mean number of total impulses per patient was 33.5±5.3. Acute PVI was achieved successfully in 251 patients (100%) according to PV signal elimination as obtained by the PFA device. In 23 patients (9.2%) incomplete PVI could be demonstrated during 3D-remapping. Rates of incomplete lesion formation differed significantly between the pulmonary veins with 26.1% for the left superior pulmonary vein (LSPV), 13% for the left inferior pulmonary vein (LIPV), 21.7% for the right inferior pulmonary vein (RIPV) and 56.5% for the right superior pulmonary vein (RSPV) (p=0.0007). In 13% of these patients more than one PV showed electrical reconduction during electroanatomic remapping.
Conclusion
Detailed 3D-electroanatomic remapping after PFA reveals incomplete PVI in nearly 10% of the patients with a majority of incomplete lesion formation found in the RSPV. Routine implementation of 3D-mapping systems might lead to a more accurate demonstration of incomplete PVI during PFA procedures and therefore help to identify patients in need of further PFA applications.