Clinical Utility of Tissue Proximity Indication With a Variable‐Loop Circular Catheter for Pulmonary Vein Isolation

BACKGROUND: The variable-loop circular catheter (VLCC, VARIPULSE) is a pulsed-field ablation (PFA) catheter equipped with a Tissue Proximity Indication (TPI) function, which monitors catheter-tissue contact. Although TPI-negative sites have been reported to contribute to gap formation, no studies have evaluated the utility of real-time function. This study assessed the success rate of pulmonary vein isolation (PVI) using the VLCC, incorporating the activated TPI function as the primary setting from the start of the procedure, representing an activated TPI function-guided ablation approach. METHODS: Between February 1 and September 3, 2025, 60 consecutive patients underwent PFA using the VLCC. After creating the 3D geometry using CARTOSOUND FAM before ablation, PVI using the VLCC was performed with the activated TPI function. After an initial two-by-two PFA set, the catheter orientation was adjusted to target areas without visible TPI-positive tags. After applying an additional PFA application to ensure a circumferential TPI function-on tags, a voltage map was created using a multielectrode catheter, and the rate of residual potentials was compared. RESULTS: Using an activated TPI function-guided PFA strategy, a first pass isolation was successfully achieved in 90% of patients (54/60) and in 97.1% of pulmonary veins (231/238). Multielectrode catheter mapping revealed residual antrum potentials in some cases, necessitating additional PFA applications in 3.8% of the pulmonary vein antrum (9/238). CONCLUSION: Activated TPI function-guided PFA was associated with a low incidence of residual PV potentials, suggesting its potential utility to improve lesion continuity and procedural efficacy.