Prognostic Value of Late Gadolinium Enhancement in Non-Ischemic Dilated Cardiomyopathy: A Prospective Observational Study from India

BACKGROUND: Non-ischemic dilated cardiomyopathy (NIDCM) represents a significant cause of heart failure and sudden cardiac death (SCD). Current risk stratification relies heavily on left ventricular ejection fraction (LVEF), which has limitations in predicting adverse outcomes. Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging may provide additional prognostic information. METHODS: This prospective observational study enrolled 88 consecutive NIDCM patients who underwent CMR imaging at our institution. Patients were followed for a minimum of 6 months and thereafter until a common study closure date, giving a mean follow-up of 337±173 days. The primary endpoint was a composite of major adverse cardiac events (MACE), defined as sudden cardiac death, heart failure death, aborted sudden cardiac death, sustained ventricular tachycardia, and heart failure hospitalization. RESULTS: LGE was present in 44 patients (50%). The most common pattern was mid-myocardial enhancement (40.9%), followed by a combination of patterns (25.0%) and transmural enhancement (22.7%); the interventricular septum was the most frequently involved segment (81.8%). MACE occurred in 22.7% of LGE-positive patients versus 13.6% of LGE-negative patients. ROC curve analysis identified LGE extent >26% of LV volume as the optimal threshold for predicting MACE (sensitivity 70%, specificity 73.5%, AUC 0.75). Patients with LGE >26% had significantly higher event rates (43.7% vs 10.7%; unadjusted OR 6.48, 95% CI 1.45-28.9; p=0.02). CONCLUSIONS: Greater LGE extent was associated with adverse cardiac events in NIDCM patients. CMR-based risk stratification may help identify high-risk patients who could benefit from ICD, but external validation in larger cohorts is required before using this threshold clinically.