B-PO04-098 EVALUATION OF LESION SIZE INDEX (LSI) PERFORMANCE TO GUIDE CAVOTRICUSPID ISTHMUS ABLATION

Abstract

Lesion size index (LSI) integrates contact force, radiofrequency current and lesion duration to provide real-time lesion formation data. To describe LSI performance and outcomes in patients undergoing cavotricuspid-isthmus (CTI) ablation at the Hospital of the University of Pennsylvania. All patients undergoing CTI-only ablation using TactiCath ablation catheter and EnSite Precision mapping were retrospectively reviewed for clinical characteristics and individual lesion data including LSI, force-time integral (FTI, gs), mean contact force (CF, g), lesion duration (s) and number of lesions. We report the 1 year procedural outcome. Between April ‘18 and December ‘19, 21 patients underwent CTI-only ablation with 100% acute procedural success (bidirectional block), no procedural complications, and no clinical recurrence after 1 year. One patient (4.8%) required redo ablation after 17 months (no clinical recurrence, but chronic reconnection was documented during atrial fibrillation ablation). Clinical characteristics (median, interquartile range [IQR]) were as follows: age 65 years (58-68), EF 55% (38-65%), CHADS-Vasc score 2 (1-4), and 19/21 were men (90.5%). A total of 605 lesion points were analyzed (median 24 lesions per patient, IQR 15-32). Lesion parameters (average, standard deviation) were as follows: LSI 5.2±0.8, FTI 238±135gs, CF 15.5±7.7g, lesion duration 16.9±10.4s. LSI best correlated with mean CF (r = 0.68) followed by FTI (r = 0.39); there was no correlation with lesion duration (r = -0.07). LSI can safely guide successful CTI ablation with mean of LSI 5.2 correlating with mean CF of 15.5g and mean FTI of 238gs.