Cardiac procedure use following acute myocardial infarction among American Indians

The prevalence of coronary heart disease is rising among American Indians (AIs), but there is limited evidence describing processes of care for AI with acute myocardial infarction (AMI). We compared rates of cardiac catheterization, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG) surgery between AI and whites with AMI.

Using data from the Nationwide Inpatient Sample and the Indian Health Service National Patient Information Reporting System, we identified 2511 AI and 316,526 whites older than 30 years admitted with AMI during 1998 to 2001. Comparisons of cardiac procedure use between AI and whites were performed after adjusting for comorbid conditions and after stratifying by geographic region.

American Indians were less likely than whites to undergo cardiac catheterization and PCI in 3 of 4 geographic regions, with the largest difference occurring in the West South Central region (OR 0.32, 95% CI 0.24 to 0.43 for catheterization; OR 0.43, 95% CI 0.31 to 0.57 for PCI). American Indians were less likely than whites to undergo CABG surgery among diabetic patients (OR 0.48, 95% CI 0.32-0.73), but not among nondiabetic patients (OR 0.90, 95% CI 0.72-1.12). There were no differences in rates of PCI and CABG surgery between AIs and whites among those receiving cardiac catheterization.

Differences in the performance of coronary procedures are concentrated in western regions of the United States and are especially related to access to cardiac catheterization. Future studies are indicated to elucidate the mechanisms of these differences in care and their impact on clinical outcomes.