Survival and Risk Factor for Mortality of Infants with Trisomy-21 and Pulmonary Hypertension: A Population-Based Study from a Middle-Income Country

Limited studies are available on the outcome of infants with trisomy-21 and pulmonary hypertension (PHT) in lower- and middle-income countries. This population-based cohort study aims to determine the outcome and survival from birth to 5 years of infants with trisomy-21 and PHT born between 2016 and 2021. The mortality rate and Kaplan-Meier survival analysis were calculated to assess survival rates at 1 and 5 years. Multivariate Cox regression analysis was used to examine mortality-related factors. A total of 488 trisomy-21 infants were identified, with 176 (36%) having PHT and 245 (50%) having congenital heart disease (CHD). Of 176 PHT, 74 (42%) had moderate to severe PHT, and 115 (65%) patients had their PHT resolved at a median age of 7 weeks (Interquartile range [IQR]: 3 to 16.8 weeks), and 48 (27%) died at a median age of 3.6 months (IQR: 0.6 to 7.1 months). The survival at 1 and 5 years was 74% and 71%, respectively. The independent factors for mortality were infants with birth weight less than 2.5 kg (adjusted Hazard Ratio [aHR] 2.1 95% confidence interval [CI] 1.1-4.2, p = .02), symptomatic infants (aHR 3.3 95% CI 1.4-7.6, p = .006), late-onset PHT (aHR 3.8 95% CI 1.6-8.9, p = .002), with CHD (aHR 2.1 95% CI 1.1-4.2, p = .03) and those with Persistent Pulmonary Hypertension of Newborn [PPHN] (aHR 2.1 95% CI 1.0-4.3, p = .047). One-third of infants with trisomy-21 experienced PHT, with seven out of ten surviving until age five. Those with low birth weight, symptomatic infants, CHD, late-onset PHT, and PPHN were associated with low survival rates.