This study aimed to compare blacks and whites admitted to coronary care units with chest pain with regard to their baseline status and their clinical features, treatment, and outcome. Data were obtained from the Myocardial Infarction Triage and Intervention (MITI) Registry, a randomized trial of pre-hospital treatment by paramedics of patients with acute myocardial infarction. Data included in the present analyses were collected from January 1988 to January 1990 for black or white persons with chest pain admitted to critical care units in 19 hospitals in metropolitan Seattle.

Among patients who were admitted for chest pain, age, hospital location (central city versus other) and discharge diagnoses differed by race, whereas gender, transporting agency (paramedic, ambulance, self or other), admission diagnosis and hospital death were similar for blacks and whites. Among patients admitted with a diagnosis of acute myocardial infarction, blacks were younger (mean age=59 years for blacks versus 67 years for whites), more likely to be admitted to a central city hospital (69% of blacks versus 33% of whites), more likely to have a history of hypertension (67% of blacks versus 46% of whites) and less likely to have had coronary bypass surgery (2% of blacks versus 10% of whites). However, gender, symptoms on admission, time from symptom onset to hospital/emergency vehicle arrival, and history of other related conditions and procedures did not differ.

During the index hospitalization for acute myocardial infarction, the use of thrombolytic therapy and cardiac catheterization did not differ for blacks and white; however, angioplasty and coronary artery surgery were used less frequently for blacks (10-12% of blacks versus 18% of whites had angioplasty, and 4-5% of blacks versus 10% of whites had coronary artery surgery). There were no racial differences in any clinical events during hospitalization. However, hospital mortality was 7.4% for blacks and 13.1% for whites (p=0.07); 5.4% for black men and 11.1% for white men; and 10.6% for black women and 16.8% for white women. After adjustment for demographic, clinical, and treatment history variables, race was no longer associated with hospital mortality in the group of patients with acute myocardial infarction (p=0.38). (The authors note the limitations of these analyses, including the lack of risk factor information such as family history and smoking.)

As possible explanatory factors for the lower utilization of coronary angioplasty and bypass surgery for blacks in comparison to whites, the authors list socioeconomic status, health insurance coverage, patient preference, extent of disease, and hospital characteristics. With regard to the lower in-hospital mortality rate for blacks compared with whites, the authors suggest that blacks may have a shorter delay between symptom onset and treatment (not included in the present analysis because of significant missing data) or blacks may have a higher out of hospital mortality rate. It was also noted that these Seattle data may not be representative of the experience in the rest of the United States.