Disparities in Rates of Acute MI Hospitalization and Coronary Procedures on the US-Mexico Border

Background: Hospitalization rates for acute myocardial infarction can provide insight into the utilization of care by disadvantaged populations. However, these data have not been reported for the US-Mexico border region. Methods: Hospital discharge public use data files for 2000 were obtained from the health departments of Arizona, California, and Texas. The diagnosis of acute myocardial infarction was based on International Classification of Diseases-9th Revision, Clinical Modification code 410 as a primary discharge diagnosis. In addition, cardiac catheterization, coronary angioplasty, and bypass grafting procedures were enumerated. Discharges were classified as occurring in hospitals in border counties and nonborder counties. Results: Overall, 12,464 hospital discharges in border counties had acute myocardial infarction listed as the first diagnosis. Among those aged 45-64 and ≥65 years in border counties, Texas had the lowest discharge rates (eg, at ≥65 years: Texas 95, California 134 per 10,000), lower than in nonborder counties. Among those aged ≥65 years, rates in Texas also were lower in border than nonborder counties, a pattern not seen in other states. On the contrary, rates of catheterization and bypass grafting were highest in Texas, whereas the rates of bypass grafting were actually higher in border than in nonborder counties. In border and nonborder counties of the combined states, hospitalization rates of acute myocardial infarction in Hispanics were lower than those of non-Hispanics. Rates varied little between border and nonborder counties within ethnic groups. A similar pattern was observed for the hospital use of angioplasty and coronary bypass surgery. Conclusions: Our findings suggest possible underutilization of hospital in-patient care for coronary artery disease by Hispanics who were residents of Texas border counties. Further studies are needed to test this hypothesis using more recent data.