Letter by Hill et al. regarding article, "Mortality in first 5 years in infants with functional single ventricle born in Texas, 1996 to 2003".

BACKGROUND Infants with functional single ventricle have a high risk of death during the early years of life. Studies have reported improvement in postoperative survival, but they do not include preoperative deaths or those occurring before transfer. The purpose of this population-based study was to estimate 5-year survival in infants with functional single ventricle, to define factors associated with survival, and to estimate improvement in outcome. METHODS AND RESULTS Patients with hypoplastic left heart syndrome, pulmonary atresia intact ventricular septum, single ventricle, and tricuspid atresia born in 1996 to 2003 were identified from the Texas Birth Defects Registry and linked to state and national birth and death vital records. We examined the effects of defect type, birth era, birth weight, gestational age, maternal race/ethnicity, extracardiac anomalies, sex, and maternal age and education on survival. Five-year survival varied by defect type: hypoplastic left heart syndrome, 38.0% (95% confidence interval, 32.6 to 43.5); single ventricle, 56.1% (95% confidence interval, 49.9 to 61.7); pulmonary atresia intact ventricular septum, 55.7% (95% confidence interval, 45.8 to 64.4); and tricuspid atresia, 74.6% (95% confidence interval, 62.4 to 83.4). The presence of extracardiac defects increased the adjusted risk of death by 84%. Non-Hispanic blacks had an adjusted risk of death that was 41% higher than that for non-Hispanic whites, and Hispanics had a 26% higher risk. Patients born in 2001 to 2003 had a 47% lower risk than those born in 1996 to 2000. CONCLUSIONS This population-based study demonstrates significant improvement in overall 5-year survival, particularly in cases of hypoplastic left heart syndrome and single ventricle. Additional studies are needed to determine the factors causing racial/ethnic and regional differences in outcome.