Targeted ablation of residual pulmonary vein potentials in atrial fibrillation ablation through ultra-high-density mapping: insights from the CHARISMA registry
Francesco Solimene 1 , Giuseppe Stabile 1 2 , Luca Segreti 3 , Maurizio Malacrida 4 5 , Vincenzo Schillaci 1 , Pietro Rossi 6 , Maria Grazia Bongiorni 3 , Gergana Shopova 1 , Filippo Maria Cauti 6 , Giulio Zucchelli 3 , Alberto Arestia 1 , Stefano Bianchi 6 , Andrea Di Cori 3 , Francesco Maddaluno 4 5 , Antonio De Simone 6 , Ignacio Garcia-Bolao 7 8
Introduction: Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (RAP) within the antral scar by means of an ultra-high density mapping (UHDM) system.
Methods: We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The LumipointTM (Boston Scientific) map-analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region.
Results: Fifty-eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3±0.2mV vs 0.7±0.5mV, p<0.0001), whereas the mean number of EGM peaks was higher (8.4±1.4 vs 3.2±1.5, p<0.0001). The percentage of patients in whom RAPs were detected through LumipointTM was higher than through propagation map analysis (58.6% vs 36.2%, p=0.025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow-up of 453±133 days, 6 patients (10.3%) suffered an AF/AT recurrence.
Conclusion: Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present.