Mortality trends for non-ST-segment elevation myocardial infarction (NSTEMI) in the United States from 1988 to 2004

Non-ST-segment myocardial infarction (NSTEMI) is one of the major causes of hospital admissions. Mortality trend in patients with NSTEMI over the years has not been studied well. The goal of this study is to explore age-adjusted long-term mortality trends from NSTEMI in the United States using a very large database.

We used the National Inpatient Sample (NIS) database, a component of the Health Care Cost and Utilization (HCUP) project, for this study. International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify NSTEMI cases in patients >40 years old. Age-adjusted mortality rates for NSTEMI cases were calculated by multiplying the age-specific mortality rates of NSTEMI by age-specific weights.

A total of 1,400,234 patients above the age of 40 years were identified. The mean age of this cohort was 77.1±10.7 years, with a total of 179,361 deaths being reported over this 16-year period. Among patients who died, 51.2% were men and 48.8% were women. The age-adjusted mortality from NSTEMI declined from 1988 (727 per 100,000) to 2004 (305 per 100,000) until the middle of the decade when mortality from NSTEMI started leveling off. Total mortality decreased from 29.6% in 1988 to 11.3% in 2004.

Our analysis showed a significant reduction in the age-adjusted and total mortality for NSTEMI over the years studied. The cause of this trend is not known but most likely reflects advancement in the treatment of patients with acute coronary syndrome.