P5783Is there a role to implantable cardioverter defibrillator for primary prevention in non-ischemic dilated cardiomiopathy?

Abstract

During the last decade implantable cardioverter defibrillator (ICD) became the mainstay of sudden cardiac death (SCD) prevention, resulting in a marked increase of ICD implantation for primary prevention. Despite the proven survival benefit of ICD in patients (P) with severe left ventricular systolic dysfunction, there is much more robust evidence in ischemic cardiomyopathy (ICM). Recent evidence has questioned the benefit of ICD implantation in nonischemic dilated cardiomyopathy (NICM). The aim of this study was to evaluate the long-term clinical impact of ICD in P with NICM for SCD primary prevention, and to investigate the predictors of ventricular tachyarrhythmic events (VTE) in this population. Methods: Retrospective, descriptive and correlation study extended to P with ICD for primary prevention in NICM. P with hypertrophic cardiomyopathy, right ventricular arrhythmogenic cardiomyopathy, left ventricle noncompaction and inherited channelopathies were excluded. Baseline clinical characteristics were analysed. Uni and multivariate analysis of markers for the occurrence of VTE with appropriate therapy (antitachycardia pacing and shock) via ICD and of overall mortality was performed. The statistical methods used were Mann-Whitney's U test, Chi-squared test and Cox regression. Results: Within a population of 126P with NICM (69% male; age 60,8+11,2 years; NYHA class II/III; 69% with a cardiac resynchronization therapy system - CRT -), 28,8% had diabetes mellitus (DM); 38,4% dyslipidemia; 60,8% hypertension (HT) and 25% permanent atrial fibrillation (AF). The mean ejection fraction (EF) was 25%. Natriuretic peptides were high in 78,4% of the P, 29,8% had creatinine clearance <60mL/min and 45,5% had nonsustained ventricular tachycardia (NSVT) on 24h Holter recording before ICD implantation. After a median follow-up time of 61months (6-139), the mortality rate was 14,3% and 2P underwent heart transplantation. Appropriate therapies occurred in 27% of the cases. The first appropriate intervention occurred after a median of 49,2 months. P with NSVT had more appropriate therapy (12 months: 14,3±4,7% vs. 3±2%; 36 months: 26,5±6,2% vs. 9,1±3,6%; 84 months: 53,2±11,3% vs. 21,4±6,1%; p= 0,005). The occurrence of NSVT before implantation was a strong predictor of appropriate ICD therapy (HR 2,59, 95% CI 1.29-5.19; p = 0,008). Gender, age, EF, NYHA class, AF, DM, HT, dyslipidemia, CRT, renal dysfunction and elevation of natriuretic peptides were not predictors of therapy via ICD. Conclusions: In a long-term follow-up period, 27% of NICM P received appropriate therapies after ICD implantation for primary prevention. NSVT seems to be a strong predictor of appropriate therapy delivered. (Figure Presented).