Comparison of the ST-Elevation Myocardial Infarction (STEMI) vs. NSTEMI and Occlusion MI (OMI) vs. NOMI Paradigms of Acute MI

J Emerg Med. 2021 Mar;60(3):273-284. doi: 10.1016/j.jemermed.2020.10.026. Epub 2020 Dec 9.


Background: The current ST-elevation myocardial infarction (STEMI) vs. non-STEMI (NSTEMI) paradigm prevents some NSTEMI patients with acute coronary occlusion from receiving emergent reperfusion, in spite of their known increased mortality compared with NSTEMI without occlusion. We have proposed a new paradigm known as occlusion MI vs. nonocclusion MI (OMI vs. NOMI).

Objective: We aimed to compare the two paradigms within a single population. We hypothesized that STEMI(-) OMI would have characteristics similar to STEMI(+) OMI but longer time to catheterization.

Methods: We performed a retrospective review of a prospectively collected acute coronary syndrome population. OMI was defined as an acute culprit and either TIMI 0-2 flow or TIMI 3 flow plus peak troponin T > 1.0 ng/mL. We collected electrocardiograms, demographic characteristics, laboratory results, angiographic data, and outcomes.

Results: Among 467 patients, there were 108 OMIs, with only 60% (67 of 108) meeting STEMI criteria. Median peak troponin T for the STEMI(+) OMI, STEMI(-) OMI, and no occlusion groups were 3.78 (interquartile range [IQR] 2.18-7.63), 1.87 (IQR 1.12-5.48), and 0.00 (IQR 0.00-0.08). Median time from arrival to catheterization was 41 min (IQR 23-86 min) for STEMI(+) OMI compared with 437 min (IQR 85-1590 min) for STEMI(-) OMI (p < 0.001). STEMI(+) OMI was more likely than STEMI(-) OMI to undergo catheterization within 90 min (76% vs. 28%; p < 0.001).

Conclusions: STEMI(-) OMI patients had significant delays to catheterization but adverse outcomes more similar to STEMI(+) OMI than those with no occlusion. These data support the OMI/NOMI paradigm and the importance of further research into emergent reperfusion for STEMI(-) OMI.

Keywords: ST-segment elevation myocardial infarction; acute coronary syndrome; acute myocardial infarction; electrocardiogram; occlusion myocardial infarction.

MeSH terms

  • Electrocardiography
  • Humans
  • Myocardial Infarction*
  • Non-ST Elevated Myocardial Infarction*
  • Retrospective Studies
  • ST Elevation Myocardial Infarction*