Changes in Controllable Coronary Artery Bypass Grafting Practice for White and Black Americans.

BACKGROUND: Racial disparities in outcomes following cardiac surgery are well-reported. We sought to determine if variation by race exists in controllable practices during coronary artery bypass grafting (CABG). We hypothesized that racial disparities exist in CABG quality metrics, but have improved over time.

METHODS: All patients undergoing isolated CABG (2000-2019) in a multi-state database were stratified into three eras by race. Analysis included propensity matched White and Black Americans. Primary outcomes included left internal mammary artery (LIMA) use, multiple arterial grafting, revascularization completeness, and guideline-directed medication prescription.

RESULTS: Of 72,248 patients undergoing CABG, Black American patients (n=10,270, 15%) had higher rates of diabetes, hypertension, prior stroke and myocardial infarction. After matching, 19,806 patients (n=9,903/group) were well-balanced. LIMA utilization was significantly different early (Era 1- Black Americans: 84.7% vs. White Americans: 86.6%, p=0.03), but equalized over time. Importantly, multi-arterial grafting differed between Black and White Americans over the entire study (9.1% vs 11.5%, p<0.001) and within each era. Black Americans had more incomplete revascularization during the study period (14.0% vs. 12.8%, p=0.02) driven by a large disparity in Era 1 (9.5% vs. 7.2%, p<0.001). Despite similar rates of preoperative use, Black Americans were more often discharged on beta-blockers (91.8% vs. 89.6%, p<0.001).

CONCLUSIONS: CABG metrics of LIMA utilization and optimal medical therapy have improved over time and are similar despite patient race. Black Americans experience less frequent multi-arterial grafting and greater discharge beta-blocker prescription. Identifying changes in controllable CABG quality practices across races supports a continued focus on standardizing such efforts.