T1 mapping and conditional survival in paediatric dilated cardiomyopathy with advanced heart failure.

Myocardial fibrosis is associated with adverse events in idiopathic dilated cardiomyopathy. Cardiac MRI with late gadolinium enhancement can detect myocardial fibrosis. We evaluated the conditional survival of children and adolescents based on native T1 mapping (combined proton signal from myocytes and interstitium prior to contrast administration by the measurement of myocardial and blood relaxation time) as a means to assess myocardial fibrosis. This retrospective case-cohort over a 3-year period included all consecutive patients (aged ≤ 21 years) with advanced heart failure from dilated cardiomyopathy (echocardiographic left ventricular ejection fraction ≤ 45% and NYHA class ≥ 2) who underwent cardiac MRI.Conditional survival (follow-up ≥ 6 months after cardiac MRI) was assessed to include NYHA functional class and time to event (death or heart transplantation). A total of 57 patients (mean age 11.7 ± 6.1 years; 58% male) had a median NYHA Class III (31/57) and median left ventricular ejection fraction 25% (20-38%). Survival data were available in 82% patients (46/57) and the crude mortality rate was 24% (11/46) and one patient (2%) underwent heart transplantation. The median native T1 was elevated at 1351 ms (95% CI 1332, 1394) and it showed no difference between the groups who survived to those who died. Performing a multilevel regression analysis on prognosis failed to predict 6-month conditional survival.