Hrev_master [page 84] [Emergency Care Journal 2025; 21:14233] Emergency Care Journal 2025 volume 21:14233 Abstract The ECG-STEMI criteria are widely used to identify Acute Myocardial Infarction (AMI) patients who need urgent revascular- ization. However, recent evidence shows that up to one-third of Occlusive Myocardial Infarctions (OMIs) may go undetected using these criteria. While still a cornerstone of current triage pro- tocols, doubts remain about their diagnostic accuracy, particularly their sensitivity in detecting OMI. This systematic review and meta-analysis aimed to assess the diagnostic accuracy of ECG- STEMI criteria in identifying patients with OMI. A comprehensive search of MEDLINE, EMBASE, and Scopus was conducted up to February 2024. Included studies enrolled patients with confirmed AMI and provided data to construct 2×2 tables comparing ECG- STEMI results (index test) with angiographic findings (reference standard) for OMI. Risk of bias was assessed using QUADAS-2. We calculated pooled sensitivity, specificity, diagnostic odds ratio (DOR), and generated SROC curves using random-effects models. Nine studies (11,757 patients) were included. ECG-STEMI criteria showed a pooled sensitivity of 0.635 (95% CI: 0.549-0.713) and specificity of 0.780 (95% CI: 0.645-0.873). The DOR was 5.94 (95% CI: 3.81-9.27), with an AUC of 0.752 (95% CI: 0.714- 0.795). Definitions of OMI varied across studies; composite defi- nitions yielded higher specificity and DOR but lower sensitivity than angiographic definitions alone. ECG-STEMI criteria offer high specificity but only moderate sensitivity for detecting OMI, potentially missing one-third of patients needing urgent care. These criteria are more reliable for confirming rather than exclud- ing OMI. Diagnostic accuracy depends on how OMI is defined, highlighting the need for a standardized definition to better assess both current and emerging ECG criteria. Introduction “Time is muscle” has become a key mantra in emergency medicine, rooted in the work of Maroko et al., who showed that early intervention—within three hours of symptom onset – can sig- nificantly reduce myocardial injury caused by coronary occlusion.1 Over the past decades, considerable efforts have aimed to improve early detection of Acute Coronary Occlusion (ACO) to maximize the benefits of timely reperfusion. The Fibrinolytic Therapy Trialists’ meta-analysis of nine randomized trials estab- lished the current STEMI/NSTEMI paradigm by demonstrating a significant mortality benefit of thrombolytic therapy in patients with ST-segment elevation, an effect not observed in those with- out. Consequently, ST-segment elevation on ECG became a surro- gate marker for ACO – a concept that remains widely accepted. Notably, these early studies were based on clinical outcomes with- out angiographic validation. Today, primary Percutaneous Coronary Intervention (PCI) has replaced systemic thrombolysis as the standard treatment.2,3 Since 2000, ECG criteria for STEMI have been revised multi- ple times, largely based on observational data, after it became clear that traditional criteria missed many cases of ACO. This led to the inclusion of “STEMI equivalents” and hemodynamically unstable Correspondence: Andrea Breglia, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, Padua, Italy. E-mail: andrea.breglia@studenti.unipd.it Key words: STEMI, NSTEMI, occlusive myocardial infarction, acute coronary occlusion, ECG, diagnostic accuracy, meta-analysis. Contributions: IC, MZ, and GR conceived the study, designed the review; IC and GR coordinated the study; MP and MV developed the search strategy, undertook searches, and organized retrieval of papers; IC and AB were responsible for the acquisition and interpre- tation of data; IC analyzed the data; IC, AB e MZ drafted the manu- script, and all authors contributed substantially to its revision. AB takes responsibility for the paper as a whole. Founding: none. Conflict of interest: there are no conflicts of interest to disclose. Ethics approval and consent to participate: not applicable. Availability of data and materials: all data generated or analyzed during this study are included in this published article. Received: 9 August 2025. Accepted: 12 November 2025. Early view: 2 December 2025. This work is licensed under a Creative Commons Attribution 4.0 License (by-nc 4.0). ©Copyright: the Author(s), 2025 Licensee PAGEPress, Italy Emergency Care Journal 2025; 21:14233 doi:10.4081/ecj.2025.14233 Publisher's note: all claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher. Missed occlusions: diagnostic accuracy of ECG STEMI criteria for identifying occlusive myocardial infarction. A systematic review and meta-analysis Ilaria Costantini,1 Andrea Breglia,2 Merisa Pilav,1 Mirko Zanatta,3 Maria V. Ventura,4 Giorgio Ricci5 1Emergency Department, Cazzavillan Hospital, Arzignano, Vicenza; 2Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, Padua; 3Emergency Department of San Lorenzo Hospital, Valdagno; 4Department of Medicine, University of Verona, Verona; 5Poison Control Center, Azienda Ospedaliera Universitaria Integrata, Verona, Italy patients among those eligible for emergent reperfusion.4-8 Despite their key role in AMI triage, studies assessing the diag- nostic accuracy of STEMI criteria have only recently emerged, and no comparative analyses have yet determined which are most effective for identifying ACO.9-11 The aim of this systematic review is to assess the diagnostic accuracy of ECG-based STEMI criteria in identifying Occlusive Myocardial Infarction (OMI) in patients with Acute Myocardial Infarction (AMI). Materials and Methods Protocol and registration This systematic review was conducted following Cochrane methodology and is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines. The study pro- tocol was registered with PROSPERO (registration number: CRD42024541580).12,13 Inclusion criteria and definitions Studies were eligible for inclusion if they enrolled patients with a high suspicion or confirmed diagnosis of Acute Coronary Syndrome (ACS). The index test assessed was the standard 12-lead Electrocardiogram (ECG), specifically evaluating the presence or absence of ST-Segment Elevation (STE), as defined by interna- tional guidelines. All studies were included regardless of the spe- cific STE criteria used. Coronary angiography was used as the reference standard, with particular emphasis on the Thrombolysis in Myocardial Infarction (TIMI) flow grade. ACO was defined as the presence of an acute culprit lesion with TIMI flow grade 0-2. We included all human studies that reported results for both the index and reference tests, allowing for the construction of a 2 × 2 contingency table. Studies were excluded if they: i) reported only test-positive or test-negative participants; ii) focused exclusively on specific sub- populations (e.g., patients with cardiac arrest, cardiogenic shock, or those undergoing PCI); iii) were animal studies, case reports, case series, or review articles; iv) were published in languages other than English. Search strategy and study selection A systematic search of MEDLINE and EMBASE was conduct- ed from inception to February 5, 2024. No restrictions were placed on study design. Only studies published in English were consid- ered. Additional reference and citation searches for included stud- ies were conducted using Scopus on September 28, 2024. The detailed search strategy for all databases is provided in Supplementary materials, Supplemental Digital Content 1. After removal of duplicates using Zotero 6.0, two reviewers (MP and MV) independently screened titles and abstracts to exclude clearly irrelevant records. The full texts of potentially eli- gible studies were then independently assessed for eligibility by the same reviewers. Discrepancies at both stages were resolved through discussion or, when needed, adjudicated by a senior author (GR). Data collection Data were independently extracted by two reviewers (IC and AB). Any disagreements were resolved through discussion with a senior author (GR). For each study, we collected general character- istics (first author, year of publication, country, study design), the STE criteria used, and the ACO definition or angiographic criteria applied. Risk of bias assessment The methodological quality of each included study was inde- pendently assessed by two reviewers (I.C. and A.B.) using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS- 2) tool (14). The results were summarized in graphical format. Data analysis and synthesis STE on ECG was defined as a test-positive result, while angio- graphically confirmed ACO represented a disease-positive status. For each study, outcomes were classified as true/false positives or negatives and recorded in Excel (Version 2016, Microsoft Corp.). Statistical analyses were performed in RStudio (Version 4.2.3) using the meta and mada packages. A univariate random-effects meta-analysis pooled sensitivity, specificity, and DORs. Bivariate models estimated the SROC curve. Stratified analyses were con- ducted based on different ACO definitions. Forest and ROC plots illustrated the distribution of diagnostic accuracy across studies. All estimates included 95% confidence intervals. A univariate meta-analysis of Positive and Negative Likelihood Ratios (PLR and NLR) was performed using a random-effects model (DerSimonian-Laird method).15 Results Study selection The database search yielded 4,933 records, and an additional 675 were identified through other sources. After removing 342 duplicates, 4,591 titles and abstracts were screened. Of these, 242 full-text articles were assessed for eligibility, and 8 studies met the inclusion criteria. Reasons for excluding the remaining 234 articles are provided in Supplementary materials, Supplemental Digital Content 2. An additional 675 records were identified through reference and citation searches via Scopus. After 205 duplicates were removed, 470 titles and abstracts were screened, resulting in 13 full-text articles reviewed. Among these, 1 study met the inclusion criteria, while 12 were excluded (reasons provided in Supplementary materials, Supplemental Digital Content 2). The study selection process is illustrated in Figure 1. Included studies This systematic review and meta-analysis included a total of 9 studies, all of which were observational. Five studies were prospective,11,16-19 while four were retrospective.9,20-22 Four studies used ECG STEMI criteria consistent with the Third or Fourth Universal Definition of Myocardial Infarction.9,11,21,22 Three studies followed the ACC/AHA STEMI guidelines (2004),16,17,19 one study applied both definitions depend- ing on the time of patient enrollment, based on the definition in use at that time,20 and one study adopted an alternative definition of ECG STEMI criteria (≥0.1 mV ST-segment elevation in two con- tiguous limb leads and/or ≥0.2 mV ST-segment elevation in two Review [Emergency Care Journal 2025; 21:14233] [page 85] contiguous precordial leads).18 In five studies,16,20 true-positive OMI cases were classified based on angiographic findings alone (TIMI flow 0-2), while in the remaining four9,11,21,22 classification was based on angiographic criteria in combination with additional diagnostic elements such as elevated troponin levels or echocar- diographic abnormalities. In these studies, markedly elevated tro- ponin levels beyond certain thresholds were interpreted as indica- tive of transmural infarction, and therefore used to classify patients as OMI rather than NOMI. Five studies explicitly aimed to evaluate the diagnostic accura- cy of ECG STEMI criteria for identifying OMI.9,11,18,21,22 In four of these, OMI was defined using a composite approach combining angiographic features with troponin levels and/or echocardio- graphic findings.9,11,21,22 The total number of participants across the 9 included studies was 11,757. Full details of the studies are pre- sented in Table 1. Risk of bias The results of the methodological quality assessment are sum- marized in Table 2 and Figure 2. Several studies showed high risk of bias, particularly in patient selection and flow/timing domains. Often, it was unclear whether all eligible AMI patients underwent angiography, and many were excluded without clear justification. Missing angiographic data Review Figure 1. PRISMA flow chart. [page 86] [Emergency Care Journal 2025; 21:14233] Figure 2. Summary of risk of bias and applicability concerns across QUADAS-2 domains. This figure shows the proportion of included studies rated as having low (green), high (orange), or unclear (blue) risk of bias (left panel) and applicability concerns (right panel) across the four QUADAS-2 domains. The greatest risk of bias was identified in the “Flow and Timing” and “Patient Selection” domains, mainly due to retrospective study designs and unclear inclusion criteria. In contrast, the “Index Test” domain consistently exhibited low risk of bias and minimal applicability concerns, reflecting standardized and appropriate ECG interpretation across studies. Review [Emergency Care Journal 2025; 21:14233] [page 87] Ta bl e 1. S um m ar y of st ud y ch ar ac te ris tic s. C U , C ar di ol og y U ni t; ED , E m er ge nc y D ep ar tm en t; IC U , I nt en si ve C ar e U ni t; TP , T ru e Po si tiv e; F P, F al se P os iti ve ; T N , T ru e N eg at iv e; F N , F al se N eg at iv e. St ud y C ou nt ry , St ud y S et tin g I nd ex te st R ef er en ce T P FP T N FN S am pl e siz e St ud y pe ri od d es ig n (S TE M I d ef in iti on ) st an da rd ( O M I d ef in iti on ) As lan ge r, 20 20 9 Tu rk ey , M ay 2 01 7- O bs er va tio na l s tu dy , E D T hi rd /F ou rth U ni ve rsa l T IM I 0 o r a ny T IM I w ith a pe ak tr op on in 8 33 1 44 6 38 34 9 1 96 4 D ec em be r 2 01 8 C on se cu tiv e, de fin iti on o f i nf ar cti on I l ev el eq ua l t o or g re ate r t ha n 1.0 n g/ m l re tro sp ec tiv e p lu s a n at lea st 20 % ri se w ith in 2 4 h or a h ig hl y ele va ted p ea k tro po ni n ( gr ea ter th an 5 .0 ng /m L) o r c ar di ac ar re st b ef or e a ny tr op on in Ba ill eu l, 20 18 16 F ra nc e, Oc to be r 2 01 0 Co ns ec ut iv e, CU A CC /A HA S TE M I TI M I f lo w 0- 1- 2 1 44 5 5 90 7 42 56 0 3 33 7 pr os pe cti ve gu id eli ne s ( 20 04 ) m ul tic en ter re gi str y Br un o, 20 21 20 S wi tze rla nd , O bs er va tio na l s tu dy , C U A CC /A HA S TE M I / TI M I f lo w 0- 1- 2 1 94 2 5 26 1 12 6 7 91 4 38 5 2 00 9- 20 17 Co ns ec ut iv e, gu id eli ne s ( 20 04 ) re tro sp ec tiv e T hi rd U ni ve rsa l de fin iti on o f i nf ar cti on In o, 20 11 17 Ja pa n, Ju ly Ob se rv ati on al stu dy , C U A CC /A HA S TE M I ) T IM I f lo w 0- 1- 2 3 4 6 3 4 1 5 8 9 2 00 8- M ar ch 2 00 9 C on se cu tiv e, pr os pe cti ve g ui de lin es (2 00 4 Ko la, 2 02 421 A lb an ia, Ob se rv ati on al stu dy , C U F ou rth U ni ve rsa l d ef in iti on Ac ut e c ul pr it les io n wi th 1 43 20 7 3 9 8 33 4 J an ua ry -M ay 2 02 3 C on se cu tiv e, of in fa rc tio n TI M I 0 –2 fl ow o r a cu te cu lp rit re tro sp ec tiv e les io n wi th T IM I 3 fl ow an d h ig hl y ele va ted tr op on in I (> 10 ,00 0 ng /L ) Ko ya m a, 20 02 18 Au str ali a, Ju ly 1 99 7 - Ob se rv ati on al stu dy , C U ≥ 0.1 m V ST -se gm en t TI M I f lo w 0- 1- 2 2 08 71 4 6 7 9 40 4 Co ns ec ut iv e, pr os pe cti ve ele va tio n in 2 co nt ig uo us lim b lea ds an d/ or ≥ 0.2 m V ST -se gm en t e lev ati on in 2 co nt ig uo us p re co rd ial le ad s M cL ar en , 2 02 322 C an ad a, Ju ne Ob se rv ati on al stu dy , E D F ou rth U ni ve rsa l d ef in iti on o f A cu te cu lp rit le sio n wi th 1 5 2 26 84 3 82 5 7 2 02 1- M ay 2 02 2 C on se cu tiv e, re tro sp ec tiv e in fa rc tio n T IM I 0 –2 fl ow o r a cu te cu lp rit le sio n w ith T IM I 3 fl ow an d hi gh ly el ev ate d t ro po ni n I ( >1 0,0 00 n g/ L) , o r i f n o an gi og ra ph y, th en h ig hl y ele va ted t ro po ni n wi th n ew re gi on al wa ll m ot io n a bn or m ali ty o n ec ho ca rd io gr am . M ey er s, 20 21 11 U SA , 1 y ea r R etr os pe cti ve ca se - ED T hi rd U ni ve rsa l A cu te cu lp rit an d eit he r 1 08 34 50 9 1 57 80 7 p er io d in 2 01 7 co nt ro l s tu dy de fin iti on o f i nf ar cti on T IM I 0 –2 fl ow o r T IM I 3 fl ow p lu s p ea k t ro po ni n T > 1.0 n g/ m L. To ut ou za s, 20 11 19 G re ec e Ob se rv ati on al stu dy , C U A CC /A HA S TE M I TI M I f lo w 0- 1- 2 2 3 7 1 6 9 5 5 Co ns ec ut iv e, g ui de lin es (2 00 4) pr os pe cti ve may have introduced selection bias, affecting diagnostic accuracy estimates. Additional bias in the reference standard domain arose from heterogeneous definitions of OMI across studies. Synthesis of results In this systematic review, a stratified meta-analysis was per- formed to assess the diagnostic accuracy of ECG-based STEMI criteria in identifying OMI in patients with AMI. The pooled sensitivity and specificity of ECG STEMI criteria were 0.635 (95% CI: 0.549-0.713) and 0.780 (95% CI: 0.645- 0.873), respectively. Subgroup estimates based on the definition of OMI are presented in the corresponding forest plots (Figures 3 and 4). Studies using an angiographic definition of OMI demonstrated higher sensitivity (0.715; 95% CI: 0.703-0.727), while those using a composite definition showed higher specificity (0.887; 95% CI: 0.804-0.937). Substantial heterogeneity was observed across stud- ies for both sensitivity (I²=95.1%) and specificity (I²=97.9%), as well as between subgroups (p=0.003 for sensitivity; p=0.001 for specificity). The overall diagnostic performance, measured by the diagnostic odds ratio (DOR), was 5.94 (95% CI: 3.81-9.27). Higher diagnostic accuracy was observed in studies using compos- ite definitions (DOR=9.31; 95% CI: 7.14-12.15), compared to those using angiographic criteria alone (DOR=4.17; 95% CI: 2.28- 7.65), with a significant difference between subgroups (p=0.0175) (Figure 5). These findings are visually summarized in the forest plots and in the summary receiver operating characteristic (SROC) curve (Figures 3 and 4). The SROC curve yielded an area under the curve (AUC) of 0.752 (95% CI: 0.714-0.795), indicating moderate diagnostic accuracy (Figure 6). The pooled positive likelihood ratio (PLR) of ECG STEMI criteria for diagnosing OMI was 2.86 (95% CI: 2.13-3.83). The pooled negative likelihood ratio (NLR) was 0.50 (95% CI: 0.43-0.59). Review Table 2. Risk of bias assessment using the QUADAS-2 tool. Risk of bias Applicability Patient Index Reference Flow and Patient Index Reference selection test standard timing selection test standard Aslanger, 20209 High Low High High High Low High Bailleul, 201816 High Low Unclear High Low Low Low Bruno, 202120 High Low Low High Low Low Low Ino, 201117 Unclear Low Low High Unclear Low Low Kola, 202421 High Low High High Low Low Low Koyama, 200218 Unclear Low Low High Unclear Low Low McLaren, 202322) High Low High High Unclear Low Low Meyers, 202111 High Low High High Low Low High Toutouzas, 201119 High Low Low High High Low Low [page 88] [Emergency Care Journal 2025; 21:14233] Figure 3. Forest plot of sensitivity estimates stratified by Occlusion Myocardial Infarction (OMI) definition. The overall pooled sensitivity across all studies was 0.635 (95% CI: 0.549- 0.713). Studies using an angiographic definition (TIMI flow 0-2 vs 3) showed higher pooled sensitivity (0.715; 95% CI: 0.703- 0.727) with no heterogeneity (I²=0%). In contrast, studies using a composite definition (angiographic plus biomarkers or echocardio- graphy) showed lower sensitivity (0.534; 95% CI: 0.403-0.660) and high heterogeneity (I²=97.3%). Subgroup difference was sta- tistically significant (p<0.05). Events: TP; Total: TP+FN; CI: con- fidence interval; I² and τ²: heterogeneity metrics. Figure 4. Forest plot of specificity estimates stratified by Occlusion Myocardial Infarction (OMI) definition. Studies using a composite definition (angiographic plus biomarkers or echocardio- graphy) showed higher pooled specificity (0.887; 95% CI: 0.804- 0.937) with substantial heterogeneity (I²=94.4%, τ²=0.3942, p< 0.0001). In contrast, studies using an angiographic definition (TIMI flow 0-2 vs 3) showed lower pooled specificity (0.636; 95% CI: 0.487-0.763) and similar heterogeneity (I²=95.1%, τ²= 0.4084, p<0.0001). The overall pooled specificity was 0.780 (95% CI: 0.645-0.873). Subgroup difference was statistically significant (p=0.0010). Events: TN; Total: TN+FP; CI: confidence interval; I² and τ²: heterogeneity metrics. Discussion This systematic review and meta-analysis assessed the diag- nostic accuracy of ECG STEMI criteria in detecting OMI among patients with AMI. A total of nine observational studies were included, encompassing 11,757 patients. Although the 12-lead ECG remains a cornerstone in the early evaluation of ACS, our findings highlight important limitations in its ability to identify OMI. The pooled sensitivity of 63.5% (95% CI: 54.9-71.3) indi- cates that over one-third of OMIs may go undetected using stan- dard STEMI criteria. This low sensitivity is likely driven by a sub- stantial proportion of false negatives.11,21,22 Importantly, transmural ischemia may present with ECG changes that fall short of STEMI thresholds, leading to delayed or missed reperfusion therapy. Reflecting this, the 2023 ESC guidelines recommend immediate revascularization also for patients with signs of ongoing ischemia consistent with STEMI equivalents.8 Conversely, specificity was relatively high at 78.0% (95% CI: 64.5-87.3), suggesting that patients meeting STEMI criteria are indeed more likely to have a true coronary occlusion. However, false positives were common, especially in studies relying solely on angiographic TIMI 0-2 flow to define OMI.16-20 Several non-occlusive conditions can mimic myocardial infarction on ECG, including myocarditis, myoperi- carditis, MINOCA, and INOCA.23 In such cases, Cardiac Magnetic Resonance (CMR) can help clarify the underlying etiology and distinguish true infarction from mimics.24 Accordingly, although ECG STEMI criteria remain valuable for confirming the presence of OMI, their moderate sensitivity and a negative likelihood ratio of 0.50 (95% CI: 0.43-0.59) limit their effectiveness as a standalone screening tool. Current clinical guidelines for the management of acute coro- nary syndromes recommend emergent coronary angiography not only in STEMI-positive patients, but also in those presenting with hemodynamic instability, regional wall motion abnormalities, or STEMI-equivalent ECG patterns. This broader approach reflects a growing awareness that relying exclusively on ST-segment eleva- tion may miss a significant proportion of patients with acute coro- nary occlusion.8,25,26 Recent evidence further supports this perspective. A systematic review and meta-analysis by McFadden et al. evaluated the diag- nostic performance of STEMI criteria in patients with ROSC fol- lowing cardiac arrest, reporting a pooled sensitivity of 70% and specificity of 85% - figures closely aligned with those observed in the present analysis.27 These findings reinforce concerns about underdiagnosis when ECG criteria are applied in isolation. However, major randomized trials investigating the role of emer- gent coronary angiography in OHCA patients without ST-segment elevation - such as the TOMAHAWK, EMERGE, and COUPE tri- als - have failed to demonstrate a clinical benefit.28-30 As a result, current guidelines do not recommend routine emergent coronary angiography for post-ROSC patients without ST elevation on the initial ECG.31 Despite the pivotal role of ECG in the early diagno- sis of myocardial infarction, few studies have been specifically designed to assess the diagnostic accuracy of STEMI criteria for detecting OMI. Of the nine studies included in this review, only five had the primary objective of evaluating ECG performance in identifying coronary occlusion n the remaining four, classification of OMI versus non-OMI was feasible based on reported data, but diagnostic accuracy was not the principal focus.16,17,19,20 This reflects a gap in the current literature and introduces potential bias, as these studies were not originally intended to assess ECG diag- nostic performance in this specific context. The studies by Meyers and Aslanger both carried a high risk of selection bias, as they were case-control analyses specifically designed to compare the diag- nostic performance of STEMI versus OMI/ACOMI criteria. In Meyers et al., sensitivity of STEMI criteria was underestimated due to an increased proportion of false negatives, as shown by the lower sensitivity observed in the case-control cohort (41%) com- pared with their earlier prospective study (62%).11,32 Similarly, Aslanger et al. selected patients based on index test outcomes (STEMI vs. NSTEMI) rather than on the target condition, further limiting the validity of diagnostic accuracy estimates.9 The retro- spective studies by McLaren and Kola, which enrolled patients consecutively in the emergency department and cardiology ward, provided more robust estimates of diagnostic performance com- Review Figure 5. Forest plot of diagnostic odds ratios (DOR) stratified by Occlusion Myocardial Infarction (OMI) definition. Studies using a composite definition (angiographic plus biomarkers or echocardio- graphy) showed a higher pooled DOR of 9.313 (95% CI: 7.136- 12.154) with moderate heterogeneity (I²=41.4%, τ²=0.0288, p=0.1630). In contrast, studies using an angiographic definition (TIMI flow 0-2 vs 3) showed a lower pooled DOR of 4.173 (95% CI: 2.277-7.650), with substantial heterogeneity (I²=90.6%, τ²=0.3749, p<0.0001). Overall pooled DOR was 5.942 (95% CI: 3.808-9.273). Subgroup difference was statistically significant (p=0.0175). Figure 6. Summary Receiver Operating Characteristic (SROC) curve. This figure illustrates the ROC curve depicting the relation- ship between sensitivity (true positive rate) and 1-specificity (false positive rate). The Area Under the Curve (AUC) indicates the test's overall accuracy. The area under the curve (AUC) is 0.752 (95% CI: 0.714-0.795), indicating moderate overall diagnostic accuracy. [Emergency Care Journal 2025; 21:14233] [page 89] pared with case-control designs. McLaren et al. reported low sen- sitivity (40.4%) but high specificity (93.8%), results consistent with Meyers despite methodological differences.22 Kola et al., by contrast, observed higher sensitivity (59.3%) but lower specificity (78.5%), likely reflecting differences in study populations, as their cohort included a broader spectrum of ACS patients.21 The prospective multicenter study by Bailleul was less affected by selection bias; however, it was limited by a high dropout rate (only 3337 of 4169 patients underwent coronary angiography) and by delays in angiography among NSTEMI patients, potentially lead- ing to misclassification of OMI status.16 The studies by Ino and Toutouzas were prospective with con- secutive enrollment, but their relatively small sample sizes limited the precision and generalizability of their findings.17,19 The study by Bruno covered a long enrollment period and applied different definitions of ECG STEMI criteria according to the guidelines available at the time, introducing variability in case classification.20 Operational definitions of OMI varied notably across studies. For instance, Kola and Meyers defined OMI as TIMI 0-2 flow or TIMI 3 flow with elevated troponin;11,21 Aslanger included cases of cardiac arrest with suspected occlusion;9 McLaren incorporated echocardiographic regional wall motion abnormalities.22 Such discrepancies likely contributed to the observed variability in diagnostic accuracy. A recent systematic review and meta-analysis by de Alencar Neto et al. reported differ- ent estimates of diagnostic accuracy for ST-segment elevation in detecting acute coronary occlusion. Their pooled sensitivity was 43.6% (95% CI: 34.7-52.9), with a specificity of 96.5% (95% CI: 91.2-98.7). In contrast, the present review found a higher sensitiv- ity of 63.5% (95% CI: 54.9-71.3) but a lower specificity of 78.0% (95% CI: 64.5-87.3).33 This discrepancy is likely due to several methodological differences. The present review included a greater number of studies (9 vs. 3) by not excluding studies based on the specific STEMI criteria applied. Additionally, the study by Lindow et al., which was included in de Alencar Neto et al.’s meta-analy- sis, was excluded from the current review because it did not meet predefined inclusion criteria. Specifically, Lindow et al. employed a composite angiographic endpoint – defined as AMI with either coronary occlusion or near-occlusion (stenosis ≥90%) – rather than the pre-PCI TIMI flow grade used as the reference standard in this review. These differences in outcome definitions and study selec- tion likely contributed to the observed variation in pooled sensitiv- ity and specificity between the two meta-analyses. Limitations The primary limitation of this review is the substantial hetero- geneity among included studies, largely attributable to inconsistent definitions of OMI. Some studies employed composite definitions that integrated angiographic, biochemical, and echocardiographic criteria, while others relied exclusively on angiographic findings. Studies employing composite definitions generally reported lower sensitivity but higher specificity, potentially reflecting more precise identification of true positives. False positives in cases with TIMI 3 flow may result from pre-angiographic treatment or spon- taneous reperfusion. Moreover, conditions like sepsis, Takotsubo syndrome, and INOCA can mimic myocardial infarction.34-36 Additional variability stems from heterogeneity in the applica- tion of STEMI criteria, study design, and patient populations, with diagnostic performance differing between cohorts with confirmed versus suspected acute coronary syndrome. These methodological and operational differences should be considered when interpret- ing pooled results. Conclusions Exclusive reliance on ECG-based STEMI criteria for identify- ing candidates for immediate reperfusion leads to underdiagnosis of nearly one-third of OMI cases. 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