Preventive catheter ablation for ventricular arrhythmias in patients with end-stage heart failure referred for heart transplantation evaluation: Rationale for and design of the CASTLE-VT trial

AimsTimely referrals for transplantation and left ventricular assist device (LVAD) play a key role in favourable outcomes in patients with advanced heart failure (HF). Cardiovascular mortality, driven by sudden cardiac death, is the main reason for dying while waiting for heart transplantation (HTx). The purpose of the Preventive Catheter Ablation for ventricular arrhythmiaS in patients with end-sTage heart faiLure rEferred for heart transplantation eValuaTion (CASTLE-VT) trial is to test the hypothesis that prophylactic catheter ablation of arrhythmogenic ventricular scar tissue will reduce mortality, need for LVAD implantation, and urgent HTx in patients with end-stage HF related to ischaemic cardiomyopathy (ICM).MethodsCASTLE-VT is a randomized evaluation of prophylactic ablative treatment of arrhythmogenic ventricular scar in patients referred for HTx evaluation and diagnosed with ICM. Ablation will be performed with the use of a substrate-based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm. The primary endpoint is the composite of all-cause mortality, worsening of HF requiring prioritized transplantation or LVAD implantation. The main secondary study endpoints are all-cause mortality, cardiovascular mortality, incidence of implantable cardioverter-defibrillator (ICD) therapy, hospitalizations, quality of life, time to first ICD therapy, number of device-detected ventricular tachycardia/ventricular fibrillation episodes, left ventricular function, and exercise tolerance. CASTLE-VT will randomize 160 patients with a follow-up period of 2 years.ConclusionCASTLE-VT will determine whether prophylactic catheter ablation of arrhythmogenic ventricular scar tissue reduces mortality in patients with end-stage HF who are referred for HTx evaluation.