Abstract 4367813: Nonischemic Late Gadolinium Enhancement Associated with Adverse Remodeling is an Underrecognized Predictor of Heart Failure Outcomes Post-Myocardial Infarction

Background: Nonischemic late gadolinium enhancement (NI-LGE) may serve as a predictor of heart failure (HF) adverse outcomes in ischemic heart disease. This study aimed to investigate the prevalence, clinical characteristics, and HF-related prognostic value of NI-LGE in post-myocardial infarction (MI) patients. Methods: A total of 956 post-MI patients (mean age: 56.2±10.9 years, 88.4% male) confirmed by cardiac MR were retrospectively included. NI-LGE was defined as mid-wall, subepicardial, or insertion point enhancement. Patients concomitant with nonischemic cardiomyopathies or myocarditis were excluded. Primary and secondary endpoints were HF- and sudden cardiac death- (SCD-) related events, respectively. Competing risk analysis was used to address the competing influence. Results: Among the 86 patients (9.0%) with NI-LGE, the most prevalent pattern and location were the mid-wall enhancement (71 patients) and the septum involvement (74 patients). NI-LGE patients had lower left ventricular ejection fraction (LVEF, 28.3%vs.36.9%, p<0.001) and larger EDVi (160.7vs.122.6, p<0.001), with EDVi independently associated with NI-LGE (OR=1.01, p<0.001). During a median follow-up of 69.6 months, 101 (10.6%) and 65 (6.8%) experienced the HF- and SCD-related events, respectively. NI-LGE was independently associated with the HF-related events (HR=5.75, p<0.001) after adjusting for the confounders. NI-LGE improved the model discrimination and fit performance (C-index: 0.84 to 0.87; Likelihood ratio: 1168.0 to 1106.1, all p < 0.001) compared with the model including NYHA class, LVEF, and LGE extent for the HF-related events. However, NI-LGE was not associated with the SCD-related events (p=0.65). In location analysis, dual-involvement patients had a higher HF-related events risk than isolated-involvement patients (HR=2.30, p<0.001). Conclusion: NI-LGE occurs in 9% of post-MI patients and is associated with adverse LV remodeling. NI-LGE serves as a promising marker of HF-related outcomes.