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 mortality. The need to identify these patients promptly is crucial, and this sets the stage for the proposed reclassification. Many of these patients can be identified by other ECG and clinical features. Background/Objectives: We sought to evaluate cases of STEMI and NSTEMI that result in OMI. Additionally, we focused on the consequences of delayed revascularization in NSTEMI patients with acute coronary occlusion (NSTEMI-OMI). Methods: The study is a retrospective analysis conducted on 334 patients who underwent coronary angiography for acute coronary syndrome at UHC “Mother Teresa”, Tirana, Albania, during January–May 2023. “OMI was defined as an acute culprit lesion with TIMI 0–2 flow, or an acute culprit lesion with TIMI 3 flow intervened upon and with highly elevated troponin (cTnI > 10.0 ng/mL, hs-cTnI > 5000 ng/L)”. The presence or absence of STEMI criteria were determined in the final diagnosis written on the chart by a cardiologist using the third universal definition of MI. Ejection fraction (EF), total ischemia time, length of stay, and complications were compared between groups. Mechanical complications include acute ventricular failure, cardiogenic shock, rupture of the interventricular septum, rupture of the free wall, rupture of the papillary muscle, and pericarditis. Electrical complications include ventricular arrhythmias, supraventricular arrhythmias, and atrioventricular and interventricular blocks. Results: There were 334 patients included, 98 (29.3%) of whom were NSTEMI-OMI patients. Ninety-six 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 h vs. 76 patients (77%) with 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 = 0.496). The overall in-hospital mortality was 19 patients (5.7%), with subgroup mortality of 14 patients (4.2%) with STEMI(+)OMI, 2 patients (0.6%) with STEMI(+) NOMI, and 3 patients (0.9%) with STEMI(−)OMI, 0% STEMI(−)NOMI, (p = 0.013). Patients with mechanical complications included 67 patients (46.8%) with STEMI(+)OMI and 45 patients (46.4%) with STEMI(−)OMI. In addition, 26 patients (18.5%) with STEMI(+)OMI and 13 patients (13.1%) with STEMI(−)OMI developed electrical complications. Conclusions: STEMI(−)OMI patients had significant delays in catheterization, yet had angiographic findings, rates 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.

Background: The STEMI/NSTEMI classification guides management and quality metrics for acute myocardial infarction (AMI). We examined whether the final cath-lab diagnosis of STEMI versus NSTEMI correlates more closely with door-to-balloon (D2B) time than with either ST-segment elevation (STE) on pre-angiogram ECG or a culprit lesion with TIMI 0-1 flow. Methods: This retrospective study analyzed 410 patients with AMI from the DOMI-ARIGATO database who underwent coronary angiography. For each patient, we recorded FDx coded by the interventional cardiologist, D2B < 120 min versus > 120 min, STE criteria (Fourth Universal Definition), and angiographic TIMI 0-1 culprit. Predictors of FDx-STE discordance were evaluated with multivariable logistic regression. Results: Among 410 angiographed AMI patients (mean age 63 ± 13; 71% male), 165 (40.2%) received an FDx-STEMI and 245 (59.8%) an FDx-NSTEMI. D2B time showed 94% agreement with FDx (160/165 FDx-STEMI treated < 120 min; 225/245 FDx-NSTEMI treated > 120 min), exceeding concordance for STE (82%; p < 0.001) and TIMI 0-1 flow (75%; p < 0.001). FDx and STE diverged in 75 patients (18%): 60 rapidly treated STE-negative cases were labelled STEMI, whereas 15 delayed STE-positive cases were labelled NSTEMI. In regression analysis, D2B < 120 min remained the sole independent predictor of discordance (adjusted OR 6.7, 95% CI 3.5–13.8). Conclusions: In this registry, the cath-lab label “STEMI” showed the strongest correlation with meeting a 120 min benchmark, exceeding correlations for STE or angiographic occlusion. These findings suggest that quality-metric compliance, rather than electrocardiographic or anatomic criteria, predominantly drives final diagnosis.

Background: Millimetric ST-segment elevation (STEMI) rules miss more than half of angiographic coronary occlusions. Re-casting acute infarction as Occlusion MI (OMI) versus Non-Occlusion MI (NOMI) and embedding that paradigm in Bayesian reasoning could shorten time to reperfusion while limiting unnecessary activations. Methods: We derived age- and sex-specific baseline prevalences of OMI from national emergency-department surveillance data and contemporary angiographic series. Pre-test probabilities were adjusted with published likelihood ratios (LRs) for chest-pain descriptors and clinical risk factors, then updated again with either (1) the stand-alone accuracy of ST-elevation or (2) the pooled accuracy of a broader OMI ECG spectrum. Two decision thresholds were prespecified: post-test probability >10% to trigger catheterization and >75% to justify fibrinolysis when angiography was unavailable. The framework was applied to five consecutive real-world cases that had elicited diagnostic disagreement in clinical practice. Results: The Bayesian scaffold re-classified three “NSTEMI” tracings as intermediate or high-probability OMI (post-test 27–65%) and prompted immediate reperfusion; each was confirmed as a totally occluded artery. A fourth patient with crushing pain and a normal ECG retained a 17% post-ECG probability and was later found to have an occluded circumflex. The fifth case, an apparent South-African-Flag pattern, initially rose to 75% but fell after a normal bedside echo and normal troponins. Conclusions: Layering pre-test context with sign-specific LRs transforms ECG interpretation from a binary rule into a transparent probability calculation. The OMI/NOMI Bayesian framework detected occult occlusions that classic STEMI criteria missed.

Background: Some authors advocate that ECGs with conventional computer algorithm (CCA) interpretations of “normal” need not be immediately reviewed. However, such ECGs may actually manifest findings of acute coronary occlusion myocardial infarction (OMI). We sought to determine if such cases can be detected by artificial intelligence (AI). Methods: Retrospective series (2014 - 2024) of cases with ≥ 1 pre-angiography ECGs with proven OMI outcome with a CCA ECG interpretation of “normal.” OMI outcome was defined as 1) diagnosis of acute type I MI, 2) angiographic culprit with intervention, 3) one of the following: a) TIMI 0-2 flow, or b) TIMI-3 or unknown flow, with high peak troponin or new wall abnormality. Each ECG was retrospectively interpreted by the PMcardio OMI AI ECG model. The primary analysis was the diagnostic performance of AI for the interpretation of CCA “normal” ECGs for OMI. Results: 42 patients with OMI met inclusion criteria. The first ECG was interpreted as “normal” by the CCA in 88% of cases; AI interpreted 81% as OMI and 86% as abnormal. Of 78 total ECGs interpreted by the CCA, 73% were diagnosed as “normal.” Of this 73%, AI identified 81% as abnormal and 72% as OMI. Conclusion: The CCA may interpret an ECG manifesting OMI as “normal.” AI not only recognized these as abnormal, but, in 81% of patients, correctly recognized OMI on the first ECG, and recognized 72% of all CCA “normal” ECGs as OMI. It was rare for AI to diagnose a normal ECG in any OMI patient.

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.