PO-01-006 CHRONIC SAFETY AND EFFICACY OF A NOVEL BASKET PFA CATHETER IN A SWINE MODEL

Abstract

Pulsed Field Ablation (PFA) is an emerging and promising form of catheter ablation for the treatment of arrhythmias. Open questions remain regarding the optimal magnitude & composition of energy delivery, electrode designs, chronic lesion performance and various safety aspects. We report on first animal data from a Novel PFA Catheter in a chronic Swine Model. Six animals were treated with a novel variable diameter, 8 spline basket, PFA, Bi-D catheter & survived for 30 days. Three veins per animal (18 total, 5 LSPV, 6 RSPV, 3 CIPV, 4 SVC) were treated with R-wave gated PFA using only 2 applications per vein with repositioning in each animal. Catheters were visualized using EnSite X & fluoroscopy. Entrance and exit block techniques were used to assess Pulmonary vein isolation at ≥30 minutes & 30 days post therapy (Tx) with a diagnostic loop (Advisor VL) & or ablation (TactiCath SE) catheter. PV stenosis was assessed using venograms with contrast from 2 views at each of the treatment sites prior to Tx & Tx+30 days in 4 animals (12 veins). Phrenic nerve function by threshold pacing (∼≤2mA, 2ms) in high SVC was assessed and fluoroscopic assessment of spontaneous diaphragm motion was conducted after Tx (N=4) & at 30 days (all). Hematoxylin & eosin, Masson’s trichrome, and S100 or Luxol fast blue (nerve) stained sections of treatment sites & collateral tissues were evaluated. PFA catheter bipole EGMs showed voltage elimination during & immediately post PFA Tx consistent with EAM post voltage maps. Functional block was seen in 18 veins (100%: 5 LSPV, 6 RSPV, 3 CIPV, 4 SVC) at Tx+30 Min & 17 veins at Tx+30 Days (94%: 4 LSPV, 6 RSPV, 3 CIPV, 4 SVC). No acute sustained arrhythmias requiring pacing were induced during PFA Tx. No venous stenosis was observed (n=0/12). All animals were recovered with intact phrenic nerve function & symmetric diaphragm motion confirmed at 30 Days. Histopathology of representative sections from all vein Tx sites revealed transmural fibrotic lesions in all but a section from the LSPV without chronic entrance block. Normal histologic architecture was also seen in sections from phrenic nerve & esophagus with no evidence of collateral ablation lesions or tissue alteration. This novel PFA delivery catheter & PFA waveform enabled electrophysiologic & histologic confirmation of chronic PV isolation with a minimum number of PFA applications, favorable usability & an optimal safety profile.