Abstract 13009: Time to Implantable Cardioverter Defibrillator in Patients With Left Ventricular Ejection Fraction ≤ 35%

Abstract

Background: Implantable cardioverter-defibrillators (ICDs) are endorsed by the current American Heart Association (AHA) Guidelines as the cornerstone in the primary prevention of mortality in patients with reduced ejection fraction (EF) (≤35%). The timing for ICD therapy in non-ischemic cardiomyopathy (NICM) is not specified in the current guidelines. The objective of this study was to determine the timing for ICD insertion for patients with NICM versus ICM in the real-world population. Methods: Retrospective design study of patients with ICDs implantation from 2019 to 2022 at our community hospital. Data was obtained via the Device Implant Registry. All eligible participants had confirmed diagnosis of ICM and NICM on chart review; while confirmed EF≤35% on echocardiography. Categorical predictors and clinical outcomes were analyzed using Pearson’s chi-square test or Fisher’s exact test. Quantitative predictors and clinical outcomes were analyzed using Student's t-test or the Wilcoxon rank sum test. Results: Our cohort included 62 patients undergoing ICD placement for primary prevention. There was no statistical significance between patients based on age, sex, race, and EF. Average time to ICD placement was 134 days for patients with ICM and 274 days for patients with NICM, a difference that favoured NICM; p =0.009 ( p <0.05). In the majority of patients, 64.5%, ICD implantation was deferred for at least 90 days compared to 35.5% patients who had an ICD placed by 90 days; p =0.001 ( p <0.05). The mortality in our study was 13% over a median of 2 years, with a predominance of ICM as compared to NICM, 75% versus 25%, respectably. Logistics regression demonstrated that timing to ICD implantation was not an independent variable of mortality. The mean overall survival was 274.4 days (SD +/- 50) in NICM compared to 134.3 days (SD +/- 21) in the ICM group, p =0.007 ( p <0.05). Conclusions: In a real-world population, time to ICD implantation was statistically different in ICM compared to NICM. ICM remains a significant risk of all-cause mortality despite the progress made in both medical and procedural treatments. Further studies are necessary to determine the appropriate time to ICD implantation in patients with NICM and reduced EF.