Myocardial infarction among southwestern American Indians.

In a 10-year study of southwestern Indians myocardial infarction was discovered only about one fourth as often as expected from the Framingham Study experience with Caucasians. The mean annual infarction rate for the southwestern Indians was 86.8/100,000 (over age 30 years), compared to the estimated 347.8/100,000 for the Framingham Study. However, coronary heart disease is not as unusual in this ethnic group as many previous investigators have suggested. During this study myocardial infarcts were discovered in 138 Indians from an estimated population of 48,196, of whom 15,905 were over 30 years of age.