Long‐term prognostic value of ultrastructural features in dilated cardiomyopathy: comparison with cardiac magnetic resonance

AIMS: This study aims to determine the implications associated with long‐term prognosis of heart failure (HF) in patients with dilated cardiomyopathy (DCM) presenting initially as decompensated HF. We stratified the phase of DCM patients without late gadolinium enhancement (LGE) based on ultrastructural changes in cardiomyocytes. METHODS AND RESULTS: Left ventricular (LV) endomyocardial biopsy was performed in 55 consecutive DCM patients with initial decompensated HF. Ultrastructural changes in cardiomyocytes detected by electron microscopy were compared with data including LGE with cardiac magnetic resonance and HF recurrence. Of the 55 DCM patients, 24 (44%) showed LGE, and 26 (47%) showed recurrence decompensated HF, while 23 patients (42%) showed autophagic vacuoles in cardiomyocytes by electron microscopy. Multivariate analysis identified atrial fibrillation [hazard ratio (HR), 3.40; 95% confidence interval (CI), 1.45–7.98], haemoglobin level (HR, 0.82; 95% CI, 0.68–0.99), beta‐blocker use (HR, 0.18; 95% CI, 0.05–0.74), and autophagic vacuoles (HR, 0.25; 95% CI, 0.09–0.65) as predictors of HF recurrence in the total patient population. In patients without LGE, only autophagic vacuoles were independent predictors of readmission because of HF (HR, 0.29; 95% CI, 0.09–0.90). In patients with LGE, atrial fibrillation (HR, 19.10; 95% CI, 2.97–123.09), and mid‐linear LGE (HR, 12.96; 95% CI, 2.02–82.94) were independent predictors of readmission because of HF. CONCLUSIONS: In DCM patients with LGE, characterised by progression of LV remodelling, the LGE pattern was a predictor of HF recurrence, whereas in patients without LGE, absence of autophagic vacuoles was a predictor of HF recurrence.