Myocardial delayed enhancement in paucisymptomatic nonischemic dilated cardiomyopathy

ObjectivesWe investigated the prognostic role of myocardial fibrosis by delayed enhancement (DE) cardiovascular magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (NICM) patients with no or mild symptoms of heart failure (HF).MethodsA prospective cohort of 125 NICM patients (82 males, age 59 ± 14 years, mean ± SD) with echocardiographic evidence of left ventricular (LV) systolic dysfunction (mean ejection-fraction 33 ± 10%), without (stage B) or with history of mild HF symptoms (stage C, NYHA classes I-II) was enrolled. The end-point was a composite of cardiac death and HF hospitalization.ResultsFifty (40%) patients showed myocardial DE, representing 12 ± 7% of LV mass. During a median follow-up of 14.2 months, 16 (32%) patients with DE experienced a composite event versus only 6 (8%) patients without DE (Kaplan-Meier survival curve, p = 0.001). After correction for age, CMR-derived LV and right ventricular volumes, echocardiographic measurements of LV diastolic function and Doppler-estimated systolic pulmonary artery pressure, the presence of DE remained a strong and independent predictor of cardiac death or HF hospitalization (hazard ratio: 5.32, 95% confidence intervals 1.60 to 17.63, p = 0.006).ConclusionsIn NICM patients with no or mild HF symptoms, the presence of myocardial DE is a strong predictor of worse clinical outcome even after correction for other established prognostic determinants. Contrast-enhanced CMR may be useful in prognostic stratification from the early stages of NICM.