Occlusion myocardial infarction missed by STEMI criteria: an angiographic emergency department cohort

Background The ST-elevation myocardial infarction (STEMI)/non-STEMI (NSTEMI) paradigm uses ST-elevation as a surrogate for acute coronary occlusion, but ST-elevation criteria miss many occlusions. The occlusion myocardial infarction (OMI) vs. non-occlusion (NOMI) paradigm classifies patients by the presence of an acute occlusion. Study objectives To compare the 2 paradigms in an angiography-selected emergency department (ED) cohort of acute myocardial infarction. Methods Retrospective single-center cohort of consecutive adults given an ED diagnosis of STEMI or NSTEMI who underwent coronary angiography between December 2021 and October 2023. OMI was defined as an acute culprit lesion with thrombolysis in myocardial infarction (TIMI) 0 to 2 flow, or culprit stenosis above 70% with a peak emergency department high-sensitivity troponin I above 10,000 ng/L. Results Of 1052 patients, 458 (43.5%) were STEMI and 594 (56.5%) NSTEMI; 837 (79.6%) met the study OMI definition. The OMI definition was met by 430 of 594 NSTEMI patients (72.4%), and 430 of 837 OMI patients (51.4%) were STEMI-negative; 51 of 458 STEMI patients (11.1%) had no occlusion. Median peak ED troponin was 155 ng/L in STEMI(+)OMI and 639 ng/L in STEMI(-)OMI (p < 0.001); median ejection fraction was 50% in both (p = 0.004). Angiography within 2 h was performed in 85.7% of STEMI(+)OMI and 15.6% of STEMI(-)OMI patients (p < 0.001). Conclusion In this angiography-selected cohort, more than half of the patients who met the study OMI definition were STEMI-negative, and these patients reached angiography far later than STEMI-positive patients with occlusion. Whether such patients can be recognized before angiography requires prospective validation of prespecified electrocardiogram (ECG) criteria.