Aim: to evaluate the association of quantitative cardiac magnetic resonance (CMR) parameters – native T1 mapping, extracellular volume fraction (ECV), and T2 mapping – with adverse clinical outcomes in adults and children with dilated cardiomyopathy (DCM).

Materials and methods. Seventy-six patients with DCM (48 adults and 28 children) underwent multiparametric CMR at 1.5 Tesla. Left ventricular volumes and function, late gadolinium enhancement (LGE), native T1 and T2 mapping, and ECV were assessed. The primary composite endpoint was death or heart transplantation. Correlation analysis, Kaplan–Meier survival analysis, and univariable Cox proportional hazards models were applied.

Results. In adults, native T1 and ECV values were significantly elevated compared with reference ranges. In simple intergroup comparison, quantitative parameters of myocardial tissue characteristics did not differ between patients with and without adverse events. However, in time-to-event analysis, higher ECV values and continuous native T1 mapping were associated with an increased risk of death or heart transplantation The main predictors of events remained a decrease in ejection fraction and an increase in left ventricular volume indices. In the pediatric cohort, native T1 and ECV were elevated relative to age-specific reference values, indicating early diffuse myocardial remodeling. Nevertheless, these parameters were not significantly associated with adverse clinical events. Left ventricular systolic dysfunction was the main determinant of prognosis in children. T2-mapping did not demonstrate a significant association with clinical events in either adults or children.

Conclusions. Quantitative CMR parameters (T1 mapping and ECV) reflect diffuse structural changes in the myocardium in dilated cardiomyopathy. In all patients, the risk of adverse clinical events (death or heart transplantation) was primarily associated with the severity of left ventricular remodeling and reduced ejection fraction, while quantitative parameters of myocardial tissue characteristics (T1-, T2-mapping, ECV) did not show significant differences in a simple intergroup comparison but may have additional value in long-term risk stratification.