Non‐ST‐Elevation Myocardial Infarction in the United States: Contemporary Trends in Incidence, Utilization of the Early Invasive Strategy, and In‐Hospital Outcomes

BACKGROUND There has been a paradigm shift in the definition of timing of early invasive strategy (EIS) for patients admitted with non-ST-elevation myocardial infarction (NSTEMI) in the last decade. Data on trends of EIS for NSTEMI and associated in-hospital outcomes are limited. Our aim is to analyze temporal trends in the incidence, utilization of early invasive strategy, and in-hospital outcomes of NSTEMI in the United States. METHODS AND RESULTS We analyzed the 2002-2011 Nationwide Inpatient Sample databases to identify all patients ≥40 years of age with the principal diagnosis of acute myocardial infarction (AMI) and NSTEMI. Logistic regression was used for overall, age-, sex-, and race/ethnicity-stratified trend analysis. From 2002 to 2011, we identified 6 512 372 patients with AMI. Of these, 3 981 119 (61.1%) had NSTEMI. The proportion of patients with NSTEMI increased from 52.8% in 2002 to 68.6% in 2011 (adjusted odds ratio [OR; per year], 1.055; 95% confidence interval [CI], 1.054 to 1.056) in the overall cohort. Similar trends were observed in age-, sex-, and race/ethnicity-stratified groups. From 2002 to 2011, utilization of EIS at day 0 increased from 14.9% to 21.8% (Ptrend<0.001) and utilization of EIS at day 0 or 1 increased from 27.8% to 41.4% (Ptrend<0.001). Risk-adjusted in-hospital mortality in the overall cohort decreased during the study period (adjusted OR [per year], 0.976; 95% CI, 0.974 to 0.978). CONCLUSIONS There have been temporal increases in the proportion of NSTEMI and, consistent with guidelines, greater utilization of EIS. This has been accompanied by temporal decreases in in-hospital mortality and length of stay.