Acute myocardial infarction hospitalization in the United States, 1979 to 2005

Abstract

Background: We reported earlier that there was no decline of acute myocardial infarction hospitalization from 1988 to 1997. We now extend these observations to document trends in acute myocardial infarction hospitalization rates and in-hospital case-fatality rates for 27 years from 1979 to 2005.

Methods: We determined hospitalization rates for acute myocardial infarction by age and gender using data from the National Hospital Discharge Survey and US civilian population from 1979 to 2005, aggregated by 3-year groupings. We also assessed comorbid, complications, cardiac procedure use, and in-hospital case-fatality rates.

Results: Age-adjusted hospitalization rate for acute myocardial infarction identified by primary International Classification of Diseases code was 215 per 100,000 people in 1979-1981 and increased to 342 in 1985-1987. Thereafter, the rate stabilized for the next decade and then declined slowly after 1996 to 242 in 2003-2005. Trends were similar for men and women, although rates for men were almost twice that of women. Hospitalization rates increased substantially with age and were the highest among those aged 85 years or more. Although median hospital stay decreased from 12 to 4 days, intensity of hospital care increased, including use of coronary angioplasty, coronary bypass, and thrombolytics therapy. During the period, reported comorbidity from diabetes and hypertension increased. Acute myocardial infarction complicated by heart failure increased, and cardiogenic shock decreased. Altogether, the in-hospital case-fatality rate declined.

Conclusion: During the past quarter century, hospitalization for acute myocardial infarction increased until the mid-1990s, but has declined since then. At the same time, in-hospital case-fatality rates declined steadily. This decline has been associated with more aggressive therapeutic intervention.