Mortality Trends in Pediatric and Congenital Heart Surgery: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

Background: Previous analyses of The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database have demonstrated a reduction over time of risk-adjusted operative mortality after coronary artery bypass grafting. The STS Congenital Heart Surgery Database (STS CHSD) was queried to assess multiinstitutional trends over time in discharge mortality and postoperative length of stay (PLOS).

Methods: Since 2009, operations in the STS CHSD have been classified according to STAT (The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery) Congenital Heart Surgery Mortality Categories. The five STAT Mortality Categories were chosen to be optimal with respect to minimizing variation within categories and maximizing variation between categories. For this study, all index cardiac operations from 1998 to 2014, inclusive, were grouped by STAT Mortality Category (exclusions: patent ductus arteriosus ligation in patients weighing less than or equal to 2.5 kg and operations that could not be assigned to a STAT Mortality Category). End points were discharge mortality and PLOS in survivors for the entire period and for 4-year epochs. The Cochran-Armitage trend test was used to test the null hypothesis that the mortality was the same across epochs, by STAT Mortality Category.

Results: The analysis encompassed 202,895 index operations at 118 centers. The number of centers participating in STS CHSD increased in each epoch. Overall discharge mortality was 3.4% (6,959 of 202,895) for 1998 to 2014 and 3.1% (2,308 of 75,337) for 2011 to 2014. Statistically significant improvement in discharge mortality was seen in STAT Mortality Categories 2, 3, 4, and 5 (p values for STAT Mortality Categories 1 through 5 are 0.060, <0.001, 0.015, <0.001, and <0.001, respectively). PLOS in survivors was relatively unchanged over the same time intervals. Sensitivity analyses reveal that the finding of declining risk-stratified rates of discharge mortality over time is not simply attributable to the addition of more centers to the cohort over time.

Conclusions: This 16-year analysis of STS CHSD reveals declining discharge mortality over time, especially for more complex operations.