To characterize the relationship between surgical volume and postoperative outcomes in congenital heart surgery, we used a national cohort to assess the costs, readmissions, and complications in children undergoing cardiac operations.

The Nationwide Readmissions Database was used to identify pediatric patients (≤18 years) undergoing congenital cardiac surgery from 2010 to 2017. Hospitals were categorized based on deciles and tertiles of annual caseload with high-volume categorized as the highest tertile of volume. Multivariable regression models adjusting for patient and hospital characteristics were used to study the impact of volume on 30-day nonelective readmission, mortality, home discharge, and resource use.

Of an estimated 69 448 hospitalizations included for analysis, 56 672 (82%) occurred at high-volume centers. After adjustment for key clinical factors, each decile increase in volume was associated with a 25% relative decrease in the odds of mortality, a 14% decrease in the odds of nonhome discharge, and a 4% relative decrease in the likelihood of 30-day nonelective readmission. After risk adjustment, each incremental increase in volume decile was associated with a one-half-day decrease in the hospital length of stay, but did not alter costs of the index hospitalization. However, after including all readmissions within 30 days of the index discharge, high-volume centers were associated with significantly lower costs compared with low-volume hospitals.

Increased congenital cardiac surgery volume is associated with improved mortality, reduced duration of hospitalization, 30-day readmissions, and resource use. These findings demonstrate the inverse relationship between hospital volume and resource use and may have implications for the centralization of care for congenital cardiac surgery.