Although racial differences in the use of cardiac procedures have been reported, there are limited data regarding the actual treatment recommendations for invasive cardiac procedures following coronary angiography. This study investigated recommendations for revascularization among 797 patients who underwent coronary angiography for the first time for the evaluation of ischemic heart disease during the period from 1990 through 1993 at an inner-city hospital. Whites were compared with non-whites, which included African Americans, Hispanics and others.

There were a number of demographic, clinical, and treatment recommendation differences between whites and non-whites. Non-whites were significantly younger and were more likely to be female, to have hypertension and diabetes, to have normal coronary arteries as per angiography, and to be given a recommendation for medical therapy (56.5% of non-whites and 45.2% of whites were recommended medical therapy versus surgery). Non-whites were significantly less likely to have undergone exercise tolerance testing prior to catheterization.

Among those with moderate coronary artery disease (CAD) (at least 50% stenosis of one or two vessels), whites and non-whites were equally likely to receive a recommendation for revascularization. There were no differences in ejection fraction, priority, or indications for catheterization in this group. The authors note that this finding was unexpected, as "one might anticipate that gender and/or racial differences would be seen in this group for whom practice guidelines are less certain (such as those with moderate CAD)." They suggest there may be "more discretion for the involved physician for treatment recommendations among patients with moderate CAD." Additionally, other unmeasured clinical/nonclinical factors may have also played a role in the final treatment decisions made.

Among those with severe (left main or triple vessel) stenosis, non-whites were more likely to have hypertension, diabetes and peripheral vascular disease; however, there were no differences in mean age, the proportion who had undergone stress testing prior to angiography, ejection fraction or catheterization priority. Among this subgroup, 79.8% of the whites versus 62.8% of the non-whites received a recommendation to undergo coronary artery bypass grafting (CABG); 83.7% of the whites versus 67.8% of the non-whites received a recommendation of percutaneous transluminal coronary angioplasty (PTCA) or CABG; and 16.3% of the whites versus 32.2% of the non-whites received recommendations for medical therapy. There were no significant differences in recommendations by gender. In this sample of patients with severe disease, after adjustment for demographic and clinical factors, blacks were 67% as likely to receive revascularization recommendations as whites, but this was not statistically significant (95% confidence interval=0.17 to 2.71). Hispanics were 39% as likely to receive revascularization recommendations as whites (95% confidence interval =0.17 to 0.92).

Medical records were retrieved for 35 of the 40 patients with severe CAD for whom only medical treatment (rather then surgical treatment) was recommended. Seven patients (2 white and 5 non-white) were later referred for revascularization. Two patients refused revascularization, two were lost to follow-up, and nine (4 white and 5 non-white) had such severe or diffuse disease that revascularization did not appear to be an alternative. No information about the other 15 was mentioned.

The authors conclude that revascularization was less likely to have been recommended to non-whites. They add, however, that "clinical factors may have accounted for most of the observed differences since nine patients were deemed inoperable due to such diffuse or distal CAD, and nonclinical factors, such as patient' preferences for less aggressive therapy and loss to follow-up. Also, the presence of language or sociocultural barriers, knowledge of risks and benefits of revascularization procedures discussion, with the patient/family or the referring physician, as well as the effect of psychosocial factors pertaining to these patients might have impacted on the physicians' decision-making process." Finally, although the authors did conclude that non-clinical factors might have a role in explaining the findings of this study, they add "how non-clinical or psychosocial factors may affect differential recommendations to coronary angiography and revascularization needs to be explored in depth and prospectively before such finding can be ascribed to racial/ethnic bias alone".