Pediatric cardiomyopathy in a resource-limited setting: clinical characteristics and determinants of medium-term outcomes.

Background and Aims: Pediatric cardiomyopathy is the leading indication for cardiac transplantation in children. However, data on its prevalence and outcomes mainly comes from developed countries, with only a scarce amount of information about its status in low- and middle-income countries. Purpose: This study aimed to characterize the clinical presentation, echocardiographic features, and outcomes of pediatric cardiomyopathy at a tertiary care center in a developing country. Methods: We conducted a retrospective review of children diagnosed with cardiomyopathy before 18 years of age at a single tertiary cardiac center over a 20-year period. Mortality at 5 years following diagnosis was assessed as a binary outcome. Univariable and multivariable logistic regression analyses were performed to identify factors associated with mortality. Results: A total of 244 children were included (mean age at diagnosis 5.9 ± 5.7 years; 57% male). Dilated cardiomyopathy was the most common phenotype, identified in 153 patients (62.7%), followed by hypertrophic cardiomyopathy in 74 (30.3%), restrictive cardiomyopathy in 10 (4.1%), and left ventricular non-compaction cardiomyopathy in 7 (2.9%). No cases of arrhythmogenic right ventricular cardiomyopathy were identified. Half of the cohort was asymptomatic at presentation and diagnosed incidentally. Presumptive myocarditis/inflammatory etiologies predominated overall and in the DCM subgroup, whereas familial/genetic etiologies predominated among patients with HCM. The 5-year mortality rate was 13.1%, with the majority of deaths occurring in children with dilated cardiomyopathy. In the overall cohort multivariable model, severely reduced left ventricular systolic function at diagnosis (adjusted OR 3.06, 95% CI 1.36-6.85) and pulmonary hypertension at diagnosis (adjusted OR 2.64, 95% CI 1.45-4.80) were the only independent predictors of mortality. Cardiomyopathy subtype, age at diagnosis, sex, and arrhythmias were not independently associated with outcome. In the In the DCM subgroup, pulmonary hypertension remained independently associated with mortality (adjusted OR 2.77, 95% CI 1.42-5.40), while severe systolic dysfunction showed a borderline association (adjusted OR 2.54, 95% CI 1.00-6.44). Conclusion: In this cohort, pediatric cardiomyopathy was characterized by a high prevalence of incidental diagnoses and a predominance of dilated phenotypes. Severe systolic dysfunction and pulmonary hypertension were the principal determinants of medium-term mortality, outweighing demographic and phenotypic factors.