Catheter ablation of sustained ventricular tachycardia in patients with structural heart disease and mildly reduced or preserved ejection fraction: results of the Preserved-AVT multicenter registry

Abstract Background Implantable cardiac defibrillators (ICDs) have demonstrated a clear survival benefit in patients with structural heart disease (SHD) and sustained ventricular tachycardia (VT). However, patients with preserved or mildly reduced ejection fraction (EF) have been underrepresented in ICD clinical trials. Catheter ablation (CA) has proven effective in reducing arrhythmia recurrence in patients with VT and SHD, and current guidelines recommend CA as a potential alternative to ICD for patients with SHD and preserved or mildly reduced EF. Despite these guidelines, limited data are available on how these patients are treated in real-world clinical practice. Purpose This multicenter international registry aimed to evaluate the clinical outcomes of patients with VT and SHD with preserved or mildly reduced EF who were treated with CA, with or without ICD implantation. Methods 205 patients (median age 69 years, median LVEF 55%, 94% NYHA ≤ 2) underwent CA for hemodynamically well-tolerated VT. 56% had ischemic cardiomyopathy, 12% dilated cardiomyopathy, 11% arrhythmogenic right ventricular cardiomyopathy. 68% of the patients received an ICD following CA. Primary endpoint was a composite of VT recurrence, sudden cardiac death (SCD) or appropriate ICD therapies. Secondary endpoint was VT recurrence rates stratified by the procedural success of CA (complete success, incomplete success, or failure). Results Complete success was achieved in 72%, incomplete success in 23%, failure in 5% of the patients. At a median follow up of 60 months the primary endpoint occurred in 24% of the patients Freedom from arrhythmic recurrence was significantly higher in patients with complete procedural success vs those with incomplete success or failure (72% vs. 43%; p=0.01, see figure 1)). At univariable analysis the number of TV induced at baseline electrophysiological study, incomplete CA procedural success and left ventricular EF above 55% were significant predictor of arrhythmias recurrences; at multivariable analysis only left ventricular EF above 55% was significantly associated with the risk of arrhythmias recurrences. No cases of SCD were reported. Clinical presentation with electrical storm, substrate ablation, procedural success on clinical VT, and overall complete or incomplete procedural success were significantly associated with the decision to implant an ICD. Survival at 60 months was 80% in the ICD group and 70% in the non-ICD group (p=0.22). Conclusions Catheter ablation of sustained monomorphic VT is highly effective in patients with SHD and preserved or mildly reduced EF. Nonetheless, the majority of these patients still receive an ICD, as reflected in our real-world clinical data. The decision to implant an ICD is guided by clinical presentation, the degree of left ventricular dysfunction, and the results of catheter ablation.