Narrowing the Survival Gap: Trends in Survival of Individuals with Down Syndrome with and without Congenital Heart Defects Born 1979 to 2018

Abstract

Objective: To evaluate the hypothesis that childhood survival for individuals with Down syndrome (DS) and congenital heart defects (CHDs) has improved in recent years, approaching the survival of those with DS without CHDs.

Study design: Individuals with DS born from 1979 to 2018 were identified through the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system administered by the Centers for Disease Control and Prevention. Survival analysis was performed to evaluate predictors of mortality for those with DS.

Results: The cohort included 1671 individuals with DS; 764 had associated CHDs. The 5-year survival in those with DS with CHD improved steadily among individuals born in the 1980s through the 2010s (from 85% to 93%; P = .01), but remained stable (96% to 95%; P = .97) in those with DS without CHDs. The presence of a CHD was not associated with mortality through 5 years of age for those born 2010 or later (hazard ratio, 2.63; 95% CI, 0.95-8.37). In multivariable analyses, atrioventricular septal defects were associated with early (<1 year) and late (>5 year) mortality, whereas ventricular septal defects were associated with intermediate (1-5 years) mortality and atrial septal defects with late mortality, when adjusting for other risk factors.

Conclusions: The gap in 5-year survival between children with DS with and without CHDs has improved over the last 4 decades. Survival after 5 years remains lower for those with CHDs, although longer follow-up is needed to determine if this difference lessens for those born in the more recent years.

Figure 1 –

Overall survival of all individuals with Down syndrome stratified by type of congenital heart defect, Metropolitan Atlanta 1979–2018; CHD= congenital heart defect, ASD = atrial septal defect, AVSD = atrioventricular septal defect, VSD=ventricular septal defect

Figure 2 –

Survival through 5 years of age for individuals with Down syndrome with and without congenital heart defects stratified by birth era, Metropolitan Atlanta 1979–2018; p-value represents results of log-rank test comparing survival across all strata; the difference in survival between those with congenital heart defects is no longer significantly lower than those without congenital heart defects for those born 2010 – 2018.