In the first national study of this issue, a team of University of Michigan researchers found that infants with specific complex heart defects are much less likely to die before leaving the hospital if they are treated at the centers that treat the largest numbers of these patients. This relationship between hospital volume and mortality has been seen in adult heart operations, but the new study suggests it holds true for infants as well.
Jennifer Hirsch, M.D., a U-M pediatric cardiac surgeon and member of the Michigan Congenital Heart Center: “Although mortality rates are much lower than 10 years ago, there is still a significant variation between centers. This study indicates that it may be time to selectively regionalize these patients’ care, to give them the best chance at a good outcome.”
Hirsch and her colleagues based their study on data from the 2003 Kids’ Inpatient Database, a national database that includes information on children hospitalized in 36 states. They analyzed data for two of the most severe congenital heart defects: transposition of the great arteries (TGA), in which the major blood vessels leading between the heart and lungs are switched, and hypoplastic left heart syndrome (HLHS), in which the left side of the heart does not develop properly.
The study shows that an infant’s risk of dying in the hospital during or after their operation varied greatly depending on the number of each procedure performed that year at the hospital where they were treated. Mortality rates ranged from more than 10 percent to less than 1 percent for the arterial switch operation, and from more than 35 percent to around 10 percent for the Norwood procedure.
“The relationship between hospital volume and risk of dying was significant across the spectrum for both defects, though in the case of arterial switch operations the difference dwindled among hospitals that performed about 15 or more in a year,” says Hirsch. “For the Norwood, the trend to decreased mortality did not level off.”
The new results suggest that for these most rare and complex of cases, infants have the best outcomes when treated at hospitals whose teams are accustomed to caring for TGA and HLHS babies.
Selectively regionalizing the care of these more severely ill infants, the researchers conclude, may be warranted based on the difference in mortality seen in the new study. But making sure that babies get to the most experienced centers in time for their operation will require commitments of resources and logistics, and a commitment by smaller congenital heart programs to refer the most complex patients early.
MEDICA.de; Source: University of Michigan Health System