OMI/NOMI: Time for a New Classification of Acute Myocardial Infarction

Forty percent of patients with acute coronary occlusion myocardial infarction (OMI) do not present with STEMI criteria, which delays their treatment and increases morbidity and mor-tality. The need to identify these patients promptly is crucial, and this sets the stage for the pro-posed reclassification. Many of these patients can be identified by other ECG and clinical fea-tures. Background/Objectives: We sought to evaluate STEMI/NSTEMI cases that result in OMI and the consequences of delayed revascularization immediately among NSTEMI patients who have ACO (NSTEMI-OMI). Methods: The study is a retrospective analysis conducted on 334 pa-tients who underwent coronary angiography for acute coronary syndrome at UHC ‘‘Mother Te-resa,’’ Tirana, Albania, during January-May 2023. OMI was defined as an acute culprit lesion with TIMI 0-2 flow, or TIMI 3 flow with highly elevated troponin (cTnI>10.0 ng/mL, hs-cTnI>5000 ng/L). Ejection fraction (EF), total ischemia time, hospital day stay and complications were com-pared between groups. Results: There were 334 patients included of whom NSTEMI-OMI were 98 patients (29.3%) of patients with ACS. 96 patients (40%) of OMI patients did not fulfill the STEMI criteria. Only 11 patients (11%) of STEMI(-)OMI had PCI performed within the first 12 hours vs 76 patients (77%) of STEMI(+)OMI, p<0.001. There was no difference in the percent of patients requiring PCI between the STEMI(+)OMI 98 patients (93%) and STEMI(-)OMI 87 patients (89%) (p<0.001). The overall in-hospital mortality was 19 patients (5.7 %), with subgroup mortality of 14 patients (4.2%) STEMI(+)OMI, two patients (0.6%) STEMI(+) NOMI, three patients (0.9%) STEMI(-)OMI, 0% STEMI(-)NOMI, (p=0.013). Patients with mechanical complications were: 67 patients (46.8%) STEMI(+)OMI and 45 patients (46.4%) STEMI(-)OMI. 26 patients (18.5%) STEMI(+)OMI and 13 patients (13.1%) STEMI(-)OMI developed electrical complications. Conclusions STEMI(-)OMI patients had significant delays in catheterization, yet had angiographic findings, rate of PCI, and complications similar to STEMI(+)OMI. These data add further support to refocusing the paradigm of acute MI to improve recognition and rapid reperfusion of all OMIs, rather than only those with STEMI criteria.