Prognostic factors in paediatric restrictive cardiomyopathy

Introduction Restrictive cardiomyopathy (RCM) is the rarest and most serious form of heart muscle disease, accounting for 2–5% of pediatric cardiomyopathies. Objective Identification of prognostic factors to identify high-risk patients that need to be addressed for early heart transplantation. Method We enrolled 47 patients that had a diagnosis of RCM between 1996 and 2017 in our center. The clinical, ultrasonography, and hemodynamic data were collected at the time of diagnosis, as well as genetic analysis in order to identify early predictors of poor prognosis (transplantation or death). Results The mean age at diagnosis was 5.9 years with a gender ratio of 1.76 (F/M). 57.5% had a pure RCM and 42.5% an hypertrophic cardiomyopathy with restrictive phenotype (HRCM). The median follow-up was 10.2 months. Overall survival at 1, 2 and 5 years was 43% 35% and 15% respectively. There was no statistically significant difference in terms of survival between RCM and HRCM ( P  = 0.651) and between age groups ( P  = 0.582). Clinical findings at diagnosis were dominated by congestive signs (63.9%), which were related to a poor outcome ( P  = 0/041). The relationship between a mildly altered left ventricular ejection fraction (LVEF 45-55%) and mortality was statistically significant ( P  = 0.01). Imaging findings didn’t show a late gadolinium enhancement. Regarding catheterism data, neither cardiac output nor pulmonary vascular resistance nor pulmonary capillary pressure were related to a poor outcome. The rentability of family screening was 60%: we identified 1 homozygous and 4 heterozygous mutations on TNNI3 gene including a neomutation, and 1 on MYH7 gene. Conclusion Adverse prognostic factors were dominated by congestive signs at diagnosis and left ventricular dysfunction. Patient with these factors should be addressed early for Heart transplantation. Autosomic dominant mutation in TNNI3 was the most frequent genetic finding. Family screening and genetic counseling is thus important.