This study compared the use of catheterization, percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass graft (CABG) surgery, and several noninvasive tests (including multiple-gated acquisition scan, stress test, and echocardiogram) for whites, African Americans, and Hispanics. Data from the California Cooperative Cardiovascular Project was used to identify patients over 65 years of age with confirmed acute myocardial infarction treated at one of the 383 nonfederal, acute care California hospitals in 1994 and 1995.

The results indicate that, even after adjusting for various demographic, medical history, and admission variables related to disease severity, African Americans were less likely than Whites to have received cardiac catheterization (29.4% vs. 38.2% respectively), PTCA (12.7% vs. 17.8%), or CABG surgery (4.6% vs. 9.7%) and more likely to have received a stress test (16.9% vs. 13.2%) or an echocardiogram (58.6% vs. 53.1%). Hispanic patients were less likely than whites to have received catheterization (35.1 vs. 38.2%, respectively) or PTCA (12.1% vs. 17.8%) but not CABG surgery, an echocardiogram, a stress test, or a multi-gated acquisition scan. Similar results were obtained when analyses were conducted in subgroups of patients who were more likely to have been eligible for the various invasive procedures.

There were several other valuable findings in this study. The authors examined the mean time to having a procedure and found that the mean time to having a cardiac catheterization differed significantly among the 3 racial/ethnic groups, with white patients having the shortest time (P<.0001). The difference in the mean time to having a CABG surgery was nearly significant, with white patients having the shortest time (P=.0551). The investigators also assessed rates of patient refusal to selected treatment and found that refusal rates for catheterization were 1.8% for whites, 1.5% for African Americans, and 2.3% for Hispanics (P=.554). Thus, the data from this study document that the “refusal rate for catheterization was low and did not differ significantly according to race.” The authors conclude that the data “allowed us to discount but not completely eliminate differences in disease prevalence, socioeconomic or insurance status, access to medical care, and the acceptance of cardiac catheterization [by the patient].”

This carefully designed study discounted several common explanations offered to explain these racial disparities, including socioeconomic, insurance status and patient preference differences (in this case differences in the refusal rate of cardiac catheterization).