Comparison between Cardiac Magnetic Resonance and Myocardial Ultrastructural Features in Patients with Dilated Cardiomyopathy to Predict Recovery of Cardiac Function

Background: Late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging is a useful modality to detect myocardial fibrosis. However, some patients with dilated cardiomyopathy (DCM) are not accompanied by LGE. Methods: Endomyocardial biopsy from left ventricle (LV) was performed in 55 consecutive DCM patients (55.5 ± 13.1 years, 82% men), at their initial presentation with decompensated HF. Ultrastructural features of cardiomyocytes were detected by electron microscopy. LV functional changes over time by trans-thoracic echocardiography were examined. Definition of LV reverse remodeling (LVRR) is increasing LV ejection-fraction (EF) from >10% to a final value of >35% at 12 months. Results: During median follow-up of 2.1 years, 12 patients (22%) were readmitted for HF recurrence. Myofilament lysis, which are apparent in degenerated cardiomyocytes of DCM, were identified in 41 (72%), and autophagic vacuoles in cardiomyocytes were identified in 24 (42%). Multiple-regression analysis showed that independent predictors of LVRR were higher Body-Mass Index (P = .031), usage of Aldosterone-Receptor Antagonist (P = .013), autophagy (P = .003), and absence of LGE (P = .015) and myofilament lysis (P = .012). Independent predictors of readmission due to HF recurrence were C-reactive protein (hazard-ratio [HR], 1.995; 95% confidence-interval [CI], 1.065–3.737), myofilament lysis (HR, 14.854; 95% CI, 1.725–127.878), and absence of autophagic vacuoles (HR, 0.055; 95% CI, 0.006–0.483). Conclusions: Ultrastructural features are useful to predict not only their prognosis, but also LVRR in patients with DCM.