Ultra-Low Cryoablation for Scar-Related VT Ablation: Results From the US Early Feasibility Study

A limitation of ablation for scar-related ventricular tachycardia (VT) is insufficient lesion depth to address nonendocardial substrate. Ultra-low temperature cryoablation (ULTC) at -196°C has been shown to create transmural lesions in preclinical models. Early human studies in Europe have shown safety and efficacy.

An EFS (Early Feasibility Study) was designed in collaboration with the Food and Drug Administration as a prospective, nonrandomized evaluation of the acute safety and effectiveness of ULTC ablation for scar-related VT.

Twenty patients (age 63±14 years; 5% women; LVEF 36±13%; 45% ischemic and 55% nonischemic) underwent VT ablation with ULTC from September to December 2023 at 4 clinical sites. Ablation strategies included substrate modification during sinus rhythm, as well as activation and entrainment mapping when hemodynamics permitted. Mean ULTC lesions were 9.9±3.6, with a total freeze duration of 47±22 minutes. Noninducibility of the targeted VTs was observed in 13 of 14 patients with inducibility tested both pre- and postablation. There were no procedural strokes, tamponades, or deaths. One suspected cardiac perforation without tamponade was conservatively managed. One patient was excluded from the follow-up efficacy analysis due to RF use, and another lacked postacute follow-up due to death from heart failure 1 month post-procedure. Among surviving per-protocol patients, 23.7±4.3 weeks of freedom from VT and implantable cardioverter defibrillator shock were 61.1% (11/18) and 83.3% (15/18), respectively.

In a US EFS, ULTC therapy was safe and effective for the treatment of scar-related VT. The EFS design, in collaboration with the Food and Drug Administration, represents an important initiative to accelerate the evaluation of new medical technologies in the United States.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05675865.