Survival and Associated Factors for Mortality Among Infants with Tetralogy of Fallot in a Middle-Income Country.

Tetralogy of Fallot (TOF) is the most common cyanotic heart disease, yet population-based survival data from low- and middle-income countries remain limited. This study evaluated survival up to 15 years of age and identified factors associated with mortality in Malaysia. This population-based cohort included all children with TOF registered in the Paediatric Cardiology Clinical Information System who were born between 2006 and 2022. Clinical characteristics and outcomes were analysed. Kaplan-Meier analysis estimated survival probabilities at 1, 5, 10, and 15 years, while Cox proportional hazards regression identified factors associated with mortality. A total of 285 TOF patients were included, with a median age at diagnosis of 8 days and a mean birth weight of 2.8 kg. Of these, 67 (24%) had an associated syndrome or non-cardiac malformation (NCM), 94 (33%) were symptomatic neonates, and 62 (22%) required staged repair. The overall mortality rate was 14%, with a median age at death of 14 months. The estimated survival rate was 94% at 1 year, 87% at 5 years, and 86% at both 10 and 15 years. Independent factors for mortality included low birth weight (aHR 3.4, 95% Confidence interval [CI] 1.6-7.2), an associated syndrome/NCM (aHR 3.7, 95% CI 1.9-7.6), and symptomatic neonates (aHR 4.4, 95% CI 1.7-11.1). Eight in 10 TOF patients survived to 15 years. Poorer outcomes were observed in low-birth-weight infants, non-isolated TOF, and symptomatic neonates, underscoring the need for improved perinatal diagnosis, neonatal care, and targeted management of high-risk infants.