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

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

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

Of 72 248 patients undergoing CABG, Black American patients (n = 10 270, 15%) had higher rates of diabetes mellitus, hypertension, prior stroke, and myocardial infarction. After matching, 19 806 patients (n = 9903 per group) were well balanced. Left internal mammary artery use was significantly different early (era 1, Black Americans 84.7% vs White Americans 86.6%; P = .03), but equalized over time. Importantly, multiarterial grafting differed between Black Americans and White Americans over the entire study (9.1% vs 11.5%, P < .001) and within each era. Black Americans had more incomplete revascularization during the study period (14% vs 12.8%, P = .02) driven by a large disparity in era 1 (9.5% vs 7.2%, P < .001). Despite similar rates of preoperative use, Black Americans were more often discharged on a regimen of β-blockers (91.8% vs 89.6%, P < .001).

Coronary artery bypass graft surgery metrics of left internal mammary artery use and optimal medical therapy have improved over time and are similar despite patient race. Black Americans undergo less frequent multiarterial grafting and greater discharge β-blocker prescription. Identifying changes in controllable CABG quality practices across races supports a continued focus on standardizing such efforts.