Blacks who suffer the most common type of cardiac ischemia – non-ST-elevation acute coronary syndrome – are less likely than whites to receive expensive or newer evidence-based treatments, according to a report in a special disparities themed issue of Circulation: Journal of the American Heart Association.
"While previous studies evaluating disparities in cardiac care have mostly focused on disparities in the use of heart catheterization between blacks and whites, this study takes a closer look at a wide range of recommended treatment options. These include newer recommended medications, heart catheterizations, and discharge recommendations for non-ST-elevation acute coronary syndrome," said the study's lead author Ali F. Sonel, M.D., assistant professor of cardiology at the University of Pittsburgh and director of the Cardiac Catheterization Laboratories at the Veterans Affairs Pittsburgh Healthcare System, where he is also a member of the Center for Health Equity Research and Promotion.
Cardiac ischemia is the lack of blood flow and oxygen to the heart. "Non-ST-elevation" acute coronary syndromes occur when there are no classic electrocardiogram changes present yet the heart is still not receiving enough oxygen.
American Heart Association and American College of Cardiology joint guidelines recommend that patients with this syndrome undergo early heart catheterization and, if indicated, either angioplasty or bypass surgery. While hospitalized, these patients should also receive aspirin, beta-blockers, newer antiplatelet drugs (including glycoprotein IIb/IIIa receptor blockers and clopidogrel), and angiotensin converting enzyme (ACE) inhibitors, if they have heart failure, diabetes or high blood pressure. Upon discharge, they should receive aspirin, beta blockers, clopidogrel, lipid-lowering therapy and ACE inhibitors if indicated as well as smoking cessation and dietary modification counseling and cardiac rehabilitation referrals as needed.
In this study, researchers reviewed data comparing how 37,813 white and 5,504 black high-risk patients with this syndrome were treated compared to the recommendations in the joint guidelines. The patient information was culled from the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines?) database – an ongoing, voluntary national quality improvement program at more than 400 hospitals nationwide.
The review showed that black high-risk patients were typically younger, female and more likely to have high blood pressure, diabetes, heart failure, and renal insufficiency than white patients. Black patients were also less likely to have insurance coverage or have a cardiologist as their primary health care provider during hospitalization.
Researchers found that high-risk blacks were as likely or more likely than whites to receive older and more established treatments such as aspirin, beta blockers, ACE inhibitors, and heparin for acute care, but were significantly less likely to receive newer drugs both on presentation and at discharge.
"Clopidogrel, glycoprotein IIb/IIIa inhibitors, and cardiac catheterization were underused in both groups, but were used much less commonly in the acute care phase among black patients compared to white patients," Sonel said.
Other study findings included:
- 29.2 percent of black patients received glycoprotein IIb/IIIa inhibitors within 24 hours compared to 35.7 percent of white patients.
- 32.1 percent of black patients received clopidogrel within 24 hours compared to 40.6 percent of white patients.
- 36.3 percent of black patients received cardiac catheterization within 48 hours of hospitalization compared to 49 percent of white patients.
- 17.5 percent of black patients received angioplasty within 48 hours, while 29.3 percent of white patients had the procedure within 48 hours.
- 8.1 percent of black patients underwent coronary bypass surgery, compared to 12.1 percent of white patients.
- At discharge, 41.6 percent of black patients were prescribed clopidogrel, compared to 53.7 percent of white patients.
- Cholesterol-lowering drugs called statins were used 70.9 percent of the time in black patients compared to 74.9 percent in white patients.
- Blacks were also less likely to receive smoking cessation counseling.
"Despite these disparities, we did not find any significant difference in short-term outcomes," Sonel said. "The death rate and combined incidence of death and post admission heart attack were about the same between blacks and whites. However, our data were limited to adverse outcomes that occurred prior to discharge, and we do not know the long-term implications of these disparities."
Researchers considered possible reasons for these disparities in treatment, such as patient demographic and clinical characteristics, provider specialty, and a variety of hospital factors. "However, racial differences in treatments persisted even after adjustment for these factors," Sonel said. "Other possible explanations for the observed disparities that were not assessed as part of this study include patient preferences, physician knowledge and attitudes, including the potential for racial bias, and styles of doctor-patient communication."
The investigators suggest future research efforts in this area should focus on a better understanding of why these disparities exist, what the long-term implications are for such disparities, and the best methods to implement evidence-based guidelines so that all clinicians have the blueprint for treatment of non-ST-elevation acute coronary syndrome and such racial disparities can be eliminated.
"If everyone is well aware of the evidence and treats every patient according to these recommendations, these disparities may be eliminated," Sonel said.
Co-authors on the study are Chester B. Good, M.D., M.P.H.; Jyotsna Mulgund, M.S.; Matthew T. Roe, M.D., M.H.S.; W. Brian Gibler, M.D.; Sidney C. Smith, Jr., M.D.; Mauricio G. Cohen, M.D.; Charles V. Pollack, Jr., M.D., M.A.; E. Magnus Ohman, M.D.; and Eric D. Peterson, M.D., M.P.H.