Clinical profile of restrictive cardiomyopathy in children at a South Indian tertiary care cardiac center: A retrospective three decade experience.

Background: Research on pediatric restrictive cardiomyopathy (RCM), especially from the developing world, is limited. The study aimed to describe the clinical features and outcomes of childhood RCM and the predictors of outcome.

Methods: The study included all children with RCM who were < 18 years old. Exclusion criteria were prior exposure to chemotherapy or radiotherapy, reduced left ventricular (LV) ejection fraction, congenital heart defects not part of any malformation syndromes, and RCM with thickened LV wall or septal thickness signifying any overlap with hypertrophic cardiomyopathy.

Results: During the 30-year study period (1990-2020), 233 cases of pediatric cardiomyopathy were identified, out of which 33 cases had RCM (14%). No RCM patient presented in the neonatal period, and 12% had presented in infancy. A syndromic, metabolic, or genetic disease was identified in 9% of cases. Endomyocardial fibrosis was diagnosed in four (12%) children. Two patients were in atrial fibrillation, one in atrial flutter, two were in junctional rhythm, and 21.8% had first-degree atrioventricular block. Twelve patients had cardiac magnetic resonance imaging done. Subendocardial late gadolinium enhancement was present in five. Out of the 33 patients, the outcome is known in 15, out of whom eight died and seven were alive. Four died of sudden cardiac death, and four from heart failure. The 5-year survival rate of RCM was calculated to be 67%, and the 10-year survival rate was 48%. The relationship between death and a history of syncope was close to statistical significance (P = 0.07).

Conclusions: RCM constituted a higher proportion of pediatric cardiomyopathies in our study than reported in most published literature. Despite relatively early clinical presentation, survival outcomes of pediatric RCM tend to be worse.