Graduation Year

2011

Document Type

Thesis

Degree

M.S.P.H.

Degree Granting Department

Epidemiology and Biostatistics

Major Professor

Wendy N. Nembhard

Keywords

aortic valve, atresia, mortality, pulmonary valve, stenosis, tricuspid valve

Abstract

Background: The etiology of congenital heart valve defects is not well understood; little is known about the risk factors that contribute to the survival and mortality outcomes of children with these defects.

Methods: Using data from the Texas Birth Defects Registry (TBDR) we conducted a retrospective cohort study of 2070 singleton infants with congenital aortic, pulmonary, or tricuspid valve atresia or stenosis born in Texas between January 1, 1996 and December 31, 2007 to Hispanic, Non-Hispanic (NH) black, and NH white women. TBDR data were death-to-birth matched by the Texas Vital Statistics Unit for deaths between January 1, 1996 and December 31, 2008. Using Kaplan-Meier survival estimates with log rank tests and Cox proportional hazards regression model hazard ratios (HR) with 95% confidence intervals (CI), we examined whether infant sex and maternal race/ethnicity affected early childhood survival or risk of mortality for children with congenital heart valve defects. Covariates included birth weight and gestational age, maternal age, maternal education, and number of co-occurring birth defects.

Results: In children with aortic valve atresia and aortic valve stenosis, we found males had higher early childhood survival than females (55.0% vs. 41.5%, P=0.0451 and 91.6% vs. 82.5%, P=0.0492, respectively). Early childhood survival for males (94.9%) with pulmonary valve stenosis was slightly lower than females (97.1%, P=0.0116), and was also lower for NH black (94.1%) and Hispanic (95.3%) children than NH white children (97.8%, P=0.0340). After adjusting for covariates, early childhood mortality in children with pulmonary valve atresia with hypoplastic right ventricle was greater in NH black than NH white children (HR=2.93, CI 1.09-7.85, P=0.0329) and greater in NH black males than NH white males (HR=4.63, CI 1.12-19.19, P=0.0349). For children with tricuspid valve atresia, early childhood survival was lower in NH black males (35.7%) and Hispanic males (64.0%) than NH white males (81.0%, P=0.0269); after adjusting for covariates, risk for early childhood mortality was higher in NH black than NH white children (HR=3.39, CI 1.41-8.13, P=0.0062), and higher in NH black males than NH white males (HR=5.23, CI 133-20.58, P=0.0179).

Conclusions: Our findings demonstrate there are disparities in early childhood survival and risk of mortality by infant sex and maternal race/ethnicity for children with congenital heart valve defects. These findings provide a foundation for further investigation to better understand why these disparities exist and what can be done to improve the outcomes for children with these defects.

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