Outcomes of major cardiac operations are not improved for black patients at black-serving institutions

Objective: Although provider-patient racial concordance has been associated with improved outcomes among patients of Black race, it is unclear if increased representation at the institutional level is associated with the same benefits. Methods: Adults undergoing coronary artery bypass grafting and valve operations were tabulated from the 2016-2020 National Inpatient Sample. Black-serving quartiles were generated using the annual proportion of Black patients admitted for all diagnoses. The primary end point was in-hospital mortality with Society of Thoracic Surgeons-defined major complications, postoperative length of stay, and costs as secondary outcomes. Mixed regression models were used to ascertain the association between Black-serving quartile designation and outcomes of interest; an interaction term was used to evaluate the incremental association of race and Black-serving quartiles. Results: Of an estimated 1,203,120 patients, 7.2% were Black. After adjustment, highest Black-serving quartile hospitals demonstrated higher odds of mortality (adjusted odds ratio, 1.18, 95% CI, 1.06-1.30) and major complications (adjusted odds ratio, 1.19, 95% CI, 1.11-1.28) compared with lowest Black-serving quartile hospitals. Notably, Black patients had significantly higher mortality compared with non-Black patients at highest Black-serving quartile institutions (3.3%, 95% CI, 3.0-3.7 vs 2.6, 95% CI, 2.4-2.8), but not at the lowest (3.1%, 95% CI, 1.8-4.4 vs 2.2, 95% CI, 2.1-2.4). Black patients exhibited a stepwise increase in risk of major complication rates, postoperative length of stay, and costs with higher Black-serving quartiles. Conclusions: Highest Black-serving quartile hospitals had worse clinical outcomes overall compared with those in the lowest Black-serving quartile. Unfortunately, Black patients had additional increased mortality, complications, postoperative length of stay, and costs at high Black-serving quartile institutions, highlighting the compounding effects of patient and hospital-level racial disparities.