Non-ST-elevation myocardial infarction in the United States: Contemporary trends in incidence, utilization of the early invasive strategy, and in-hospital outcomes

Abstract

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.