Center case volume is associated with Society of Thoracic Surgeons-defined failure to rescue in cardiac surgery

Objective: Our understanding of the impact of a center's case volume on failure to rescue (FTR) after cardiac surgery is incomplete. We hypothesized that increasing center case volume would be associated with lower FTR.

Methods: Patients undergoing a Society of Thoracic Surgeons index operation in a regional collaborative (2011-2021) were included. After we excluded patients with missing Society of Thoracic Surgeons Predicted Risk of Mortality scores, patients were stratified by mean annual center case volume. The lowest quartile of case volume was compared with all other patients. Logistic regression analyzed the association between center case volume and FTR, adjusting for patient demographics, race, insurance, comorbidities, procedure type, and year.

Results: A total of 43,641 patients were included across 17 centers during the study period. Of these, 5315 (12.2%) developed an FTR complication, and 735 (13.8% of those who developed an FTR complication) experienced FTR. Median annual case volume was 226, with 25th and 75th percentile cutoffs of 136 and 284 cases, respectively. Increasing center-level case volume was associated with significantly greater center-level major complication rates but lower mortality and FTR rates (all P values < .01). Observed-to-expected FTR was significantly associated with case volume (P = .040). Increasing case volume was independently associated with decreasing FTR rate in the final multivariable model (odds ratio, 0.87 per quartile; confidence interval, 0.799-0.946, P = .001).

Conclusions: Increasing center case volume is significantly associated with improved FTR rates. Assessment of low-volume centers' FTR performance represents an opportunity for quality improvement.