Circulation: Clinical Summaries

There has been significant controversy about the effect of prenatal diagnosis of critical congenital heart disease on mortality, and many large studies have demonstrated no benefit. The authors take a novel approach to this question in neonates with hypoplastic left heart syndrome in 2 ways: (1) they use the Texas Birth Defects Registry, which allows for capture of death prior to transfer to a cardiac surgical center (CSC) and before surgery after transfer, and (2) distance between the birth hospital and a CSC (measured in calculated driving time) is investigated instead of prenatal diagnosis. The results demonstrated that birth >90 minutes from a CSC was associated with increased neonatal mortality compared with <10 minutes away, even when controlling for known risk factors. When timing of death was investigated, the majority of mortality associated with increased distance was pre-transfer and pre-surgical after transfer. Specifically, birth >90 minutes from a CSC was associated with >6-fold higher mortality before transfer than in patients born closer, with a similar effect seen even in those prenatally diagnosed. Birth 10 to 90 minutes from a CSC was associated with higher presurgical mortality after transfer, compared with those born <10 minutes away. The study also confirmed the association between low case volume and higher surgical mortality, and suggested that low case volume may also be associated with higher presurgical mortality. Efforts to improve prenatal diagnosis of hypoplastic left heart syndrome and subsequent delivery near a large volume CSC may therefore significantly improve neonatal survival in infants with hypoplastic left heart syndrome. See p 285.