Taylor HA Jr, Canto JG, Sanderson B, Rogers WJ, Hilbe J.
Management and outcomes for black patients with acute myocardial infarction in the reperfusion era. National Registry of Myocardial Infarction 2 Investigators.
Am J Cardiol 1998;82(9):1019-23.

The objective of this study was to examine the current state of treatment and in-hospital mortality for black patients with myocardial infarction compared with white patients using data from the National Registry of Myocardial Infarction 2. These data were collected as part of a multi-center voluntary study of patients diagnosed with acute myocardial infarction (MI) during the period from June 1994 to April 1996. It is a non-random, convenience sample of patients from more than 1,400 medication centers throughout the United States. In this report, only clinical factors useful to confirm the diagnosis of MI were listed as inclusion criteria.

There were notable racial differences in medical history and presenting characteristics of patients in this study. Additionally, blacks presented later after symptom onset (median MI symptom to arrival time was 145 days for blacks and 122 days for whites).

In analyses that adjusted for baseline differences in age, sex, insurance status, history, clinical characteristics, hospital characteristics, and U.S. region, black patients were 24% less likely to receive thrombolytic therapy than white patients (adjusted OR for blacks compared with whites=0.75; 95% confidence interval=0.70-0.82). (Note: There are discrepancies between the data provided in the text and the abstract with regard to the confidence interval for the OR for thrombolytic therapy.) Black and white patients were equally likely to receive immediate angioplasty (adjusted OR=0.96; 95% confidence interval=0.84-1.10). With regard to invasive procedures, blacks were significantly less likely to undergo coronary arteriography, coronary angioplasty, and coronary bypass surgery. Although statistically significant, there were only small (unadjusted) differences in pharmacologic therapies, with the exception of the significantly higher use of angiotensin-converting enzyme inhibitors and calcium blockers among blacks compared with whites. Finally, time to receiving an electrocardiogram and the time to undergoing acute reperfusion therapy (among patients receiving this treatment) were longer for black than white patients.

With regard to clinical events and outcomes, the (unadjusted) race comparisons of the number of recurrent ischemia, recurrent infarction, heart failure, cardiogenic shock, ventricular fibrillation/tachycardia, stroke, as well as the comparison of the ejection fraction mean, showed minimal differences. After adjusting for clinically relevant variables, there were no significant race differences in overall in-hospital mortality. However, age-specific analyses showed that young black patients (<40 years) had a three-fold higher risk for death than young white patients.

The authors conclude that disparities between blacks and whites persist with regard to timeliness and level of care. As possible explanations for fewer black patients receiving intravenous thrombolysis, they suggest unmeasured confounders that affect the process of care and physician bias in the use of aggressive thrombolytic therapies. The authors also suggest that the similar in-hospital mortality rates between blacks and whites may reflect higher pre-hospitalization death rates. Alternatively, the early in-hospital mortality figures may mask an eventual excess in later mortality among blacks.