PO-05-031 CATHETER ABLATION AS FIRST LINE TREATMENT IN PATIENTS WITH ISCHEMIC CARDIOMYOPATHY, TOLERATED VENTRICULAR TACHYCARDIA AND LEFT VENTRICULAR EJECTION FRACTION ≥35%: LONG TERM OUTCOMES

Abstract

Patients with ischemic cardiomyopathy (ICM) and ventricular tachycardia (VT) are at risk for sudden cardiac death (SCD). Prior studies have suggested that patients with well-tolerated VTs and preserved/moderately reduced left ventricular ejection fraction (LVEF) and successful VT ablation may not benefit from cardioverter defibrillator implantation (ICD). Current guidelines indicate that in selected patients catheter ablation should be considered instead of ICD. This study aims to analyze arrythmia outcomes of ICM patients referred for VT ablation without prior ICD implantation according to LVEF, tolerance of VT and ablation outcome. ICM patients without prior ICD implantation undergoing VT ablation in a single center between 2009 and 2022 were included. Patients who presented with tolerated VT and who had a LVEF≥35% were offered catheter ablation (CA) as first-line therapy. Patients were categorized according to (1) LVEF, (2) hemodynamical tolerance of VT, and (3) acute ablation outcome. According to the institutional protocol, ICD was offered to all patients after ablation. Eighty-six patients (mean age 69±9 years, 84% male, mean LVEF 41±9%) underwent VT ablation. The median presenting VT cycle length (VTCL) was 323ms [300 – 375] and was tolerated in 67% (tolerated VTCL 325ms [300 – 371]). In 66 patients, the LVEF was ≥35%, of which 51 had well-tolerated VT. Of these 51 patients, 37 (73%) were rendered non-inducible and in 14 patients non-clinical VTs remained inducible (median VTCL 238ms [203-288]). In 5/37 non-inducible and in 11/14 inducible patients, an ICD was implanted. Of the 35 patients who had LVEF<35% and/or non-tolerated VTs, 7 refused ICD implantation. During a median follow-up of 35 [22 – 53] months, 10 patients (12%) had VT-recurrence and one patient with an ICD had SCD. Overall mortality was 22%. In the 37 patients with LVEF≥35%, tolerated VT and non-inducibility post procedure, no SCD or VT-recurrence was observed. Also, in this group no patient was using AAD for VT at last follow-up. In the 14 remaining patients with LVEF≥35% and tolerated VT who were inducible after ablation, no SCD occurred but VT recurred in 29% (median VTCL 303ms [200-374]). This study supports that ICM patients without prior ICD and LVEF≥35% with hemodynamically well-tolerated VT and are non-inducible after ablation have an excellent prognosis. Successful catheter ablation without ICD implantation seems to be safe in these selected patients.