This study compared demographic and clinical characteristics, treatment patterns, and clinical outcomes among Hispanics (people having origins in Mexico, Puerto Rico, Cuba, Central or South American, or any other Spanish culture or origin), Asian-Pacific islanders (people having origins in China, Taiwan, Korea, Japan, Thailand, Singapore, Philippines, and India, as well as other countries in Asia and islands of the Pacific), and Native Americans (referring to North American Indian and Eskimos) with those of white Americans presenting to the hospital with acute myocardial infarction (AMI). "Blacks were not included in this analysis in order to allow a unique opportunity to describe the management and outcome of non-black minorities with AMI, whose experiences have traditionally been underreported when compared with blacks and whites."

The data used for this study were collected as part of the National Registry of Myocardial Infarction 2 (NRMI 2), a multi-center voluntary database designed to collect, analyze and report cross-sectional data on patients admitted with myocardial infarction at participating hospitals. Participating hospitals are strongly encouraged to consecutively enroll all patients diagnosed with AMI (this enrollment process has not, however, been verified or validated). This analysis reports the findings for 275,046 AMI consecutive patients enrolled in the NRMI 2 from June 1994 to April 1996.

Native Americans and Hispanics presented to the hospital much later after AMI symptom onset than whites (144 minutes for Native Americans, 135 minutes for Hispanics versus 122 minutes for whites). Native Americans and Hispanic also tended to use ambulance services less frequently than whites (39% of Native Americans, 44% of Hispanics versus 47% of whites).
Asian-Pacific Islanders did not significantly differ from whites with regard to either of these variables, but Asian-Pacific Islanders were less likely to present with chest pain. Vital signs, Killip class, frequency of ST elevation on the first electrocardiogram did not differ substantially among the groups. Overall non-black minorities were more likely than whites to present at moderate- to large-sized hospitals and to facilities with more on-site coronary arteriography, coronary angioplasty, and coronary bypass surgery capabilities.

After adjusting for clinical differences, Hispanics and Native Americans were as likely as whites to receive thrombolytic therapy, but Asian-Pacific islanders (who were less likely to present with chest pain) were less likely to receive thrombolytic therapy (OR=0.84; 95% confidence interval=0.72 to 0.99). The time interval from hospital arrival until initiation of thrombolytic therapy was longer in non-black minorities than in whites (50 versus 45 minutes), and this time interval was even more prolonged for Native Americans (62 versus 45 minutes). There were no statistically significant differences in use of primary angioplasty, coronary arteriography, or coronary bypass surgery among the groups. However, among patients having primary angioplasty, the interval from hospital arrival to balloon inflation was prolonged among Native Americans compared with whites (275 versus 152 minutes).

Within the first 24 hours after hospital arrival, Asian-Pacific Islanders were less likely to receive aspirin, heparin, and lidocaine than whites, and all non-black minorities groups were less likely to receive beta blockers than whites. At discharge, Hispanics were less likely to receive beta blockers and calcium blockers than whites, and Asian-Pacific Islanders were less likely to receive calcium blockers. These differences were statistically significant at the p<0.001 level. Other racial patterns were noted, but they were not substantial.

There were only minor differences in event rates of recurrent ischemia, cardiogenic shock, ventricular arrhythmias and stroke (which the authors characterized as not being clinically important). Adjusted mortality figures were also similar across groups. However, in an age-specific analysis, Hispanics who were less than 40 years old had a fourfold higher mortality risk than similarly aged whites (OR=4.04, 95% confidence interval=1.24 to 13.10). It is noteworthy that this included only 4% of the study population.

These data are among the first documenting the clinical characteristics of non-black minority patients treated for myocardial infarction. The authors note several limitations, including their inability to control for socioeconomic class, employment, income, preadmission medications, and other comorbid diseases. Additionally, this registry reflects the treatment and hospital outcomes among those who survive AMI and reach the hospital, and not those patients who died before hospital arrival (or those who never came to a hospital).