An observational study in Acute Coronary Syndromes, Chest Pain and Myocardial Infarction (MI), sponsored by University Medical Centre Maribor. Not yet recruiting at 1 site in Slovenia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by University Medical Centre Maribor · Observational
Chest pain is among the most common reasons people attend an emergency department, and the electrocardiogram (ECG) recorded at triage is the first test used to decide who needs urgent treatment for a blocked coronary artery. Recognising the ECG patterns that indicate an acutely blocked artery is difficult. Many such patterns do not produce the classic ST-segment elevation, and identifying them reliably requires a level of ECG expertise that is not always available at the point of triage - particularly at night and among clinicians who are not cardiologists.
Artificial intelligence (AI) models that read the 12-lead ECG have been shown in several retrospective studies, mainly from Western Europe and the United States, to identify acute coronary occlusion more sensitively than conventional interpretation. These models are now in clinical use in a number of health systems. Their performance has not been assessed in a prospectively enrolled, unselected Slovenian emergency department population, and diagnostic accuracy commonly declines when a model is applied outside the setting in which it was developed.
TRIACS is a prospective, single-centre, observational external validation study in the Emergency Department of University Medical Centre Maribor. All consecutive adults presenting with symptoms suggestive of acute coronary syndrome who have a 12-lead ECG recorded at triage as part of routine care will be enrolled. Each triage ECG is analysed by the AI model. The model's output is withheld from all treating clinicians and plays no part in patient care; every patient receives standard guideline-directed management.
The main aim is to measure how accurately the AI model identifies angiographically confirmed occlusion myocardial infarction in this population, and to compare its accuracy with the triage decision actually made by the clinical team. The study is therefore designed to inform an adoption decision in either direction, rather than to demonstrate a predetermined conclusion.
**Background.** Approximately one quarter to one third of patients ultimately diagnosed with non-ST-elevation myocardial infarction have an acutely occluded culprit artery, and delayed invasive management in this group is associated with substantially higher mortality. The Fifth Universal Definition of Myocardial Infarction (2026) has broadened the formal electrocardiographic criteria for myocardial ischaemia to include ST-segment depression patterns, posterior and right-sided lead criteria, the Aslanger pattern, the South African flag sign and modified Sgarbossa criteria. Applying these criteria reliably requires expert-level ECG interpretation. The practical diagnostic gap at the point of triage is therefore now less a matter of criteria than of the expertise available to apply them.
AI-based ECG interpretation has demonstrated superior sensitivity to conventional millimetre criteria in retrospective multicentre cohorts and is in clinical deployment in several health systems. Prospective validation in unselected emergency department populations remains limited, and reported accuracy commonly declines on external validation.
symptoms or signs consistent with myocardial ischaemia, AND acute myocardial injury demonstrated by a dynamic rise and/or fall in high-sensitivity cardiac troponin I with at least one value above the sex-specific 99th percentile upper reference limit, meeting the criteria for **primary myocardial infarction** under the Fifth Universal Definition of Myocardial Infarction (2026), AND angiographic evidence of an acute culprit lesion with either (a) TIMI flow grade 0-1, or (b) TIMI flow grade 2-3 with emergent or urgent percutaneous revascularisation.
Under the Fifth UDMI an isolated troponin elevation without ischaemic symptoms or signs constitutes myocardial injury, not infarction, and does not satisfy this definition. Primary myocardial infarction is no longer restricted to atherothrombosis and encompasses spontaneous coronary artery dissection, coronary embolism and vasospasm; such cases meet the reference standard where the angiographic criterion is satisfied. Myocardial injury with non-obstructive coronary arteries (MINOCA, a working rather than final diagnosis under the Fifth UDMI) is adjudicated as OMI-negative and reported as a named category.
Because coronary angiography is not performed in all patients, a composite reference standard is used with the verification route pre-specified:
Ambiguous or discordant cases are reviewed by a second independent adjudicator, with disagreement resolved by consensus. Inter-adjudicator agreement is reported (Cohen's kappa).
1,492 studies on the registry are indexed under Acute Coronary Syndrome; 270 are open to participants now.
This study's planned enrollment of 1,000 is above the median of 500 across 579 observational studies indexed under Acute Coronary Syndrome.
Browse Acute Coronary Syndrome studies →University Medical Centre Maribor is the lead sponsor of 36 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
All adults presenting to ED of UKC Maribor, triaged as chest pain that have ECG recorded and agree to be included into study.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Consecutive adults with a digitally captured triage 12-lead ECG. No intervention assigned; AI analysis performed on routinely acquired ECGs with output withheld from clinicians.
Diagnostic accuracy of the AI-ECG model for angiographically confirmed occlusion myocardial infarction
Sensitivity, specificity, positive predictive value, negative predictive value, overall accuracy and area under the receiver-operating characteristic curve of the AI model's verdict on the first 12-lead ECG recorded at triage, against the pre-specified composite reference standard for OMI. The decision threshold is fixed a priori at the manufacturer's on-label cut-off; no threshold optimisation is performed.
Time frame: From triage ECG to 7 and 30 days after index presentation
Comparative diagnostic accuracy versus formal STEMI criteria
Compared with the full ECG criteria for myocardial ischaemia and infarction under the Fifth UDMI (2026): the thresholds in 2a, plus new horizontal or down-sloping ST-segment depression ≥0.5 mm at the J-point in two or more contiguous leads; T-wave inversion \>1 mm in two contiguous leads; posterior infarction patterns (ST-depression ≥1 mm in V1-V3, particularly with dominant R wave, confirmed by ST-elevation in V7-V9); right ventricular infarction (ST-elevation in V3R-V6R); the Aslanger pattern; the South African flag sign; and modified Sgarbossa criteria in LBBB and ventricular pacing. Applied by a blinded reviewer.
Time frame: From triage ECG to 7 and 30 days after index presentation
Versus conventional ST-elevation millimetre criteria
Compared with ST-elevation at the J-point in two contiguous leads: ≥1 mm in all leads other than V2-V3; in V2-V3, ≥2 mm in men ≥40 years, ≥2.5 mm in men \<40 years, ≥1.5 mm in women. Applied by a blinded reviewer. Retained because it corresponds to the criteria used in the prior validation literature and permits direct comparison with those cohorts.
Time frame: From triage ECG to 7 and 30 days after index presentation
Proportion of triage ECG recordings successfully linked to the patient record
Proportion of 12-lead ECGs recorded at triage that are successfully linked to the correct patient encounter using barcode scanning of the patient wristband label, with the denominator being all triage ECGs recorded in patients presenting with chest pain.
Time frame: During the index ED visit, over the 12-month recruitment period
Diagnostic accuracy of AI-based ECG analysis in pre-specified patient subgroups
Sensitivity, specificity and AUROC with 95% confidence intervals, calculated separately within pre-specified subgroups: sex; age category (\<65, 65-79, 80 years and over); estimated glomerular filtration rate (\<60 vs 60 mL/min/1.73 m² and above); Manchester triage acuity category; reported duration of symptoms; and mode of arrival (ambulance vs self-presentation). These analyses are exploratory and hypothesis-generating; no formal adjustment for multiple comparisons is planned, and differences between subgroups will be interpreted descriptively.
Time frame: Through 30 days after the index ED visit
Proportion of enrolled patients for whom an initial high-sensitivity troponin result is retrievable, stratified by care pathway and by triage stream. Reported with reasons for non-retrievability
Proportion of enrolled patients for whom an initial high-sensitivity troponin result is retrievable, stratified by care pathway and by triage stream. Reported with reasons for non-retrievability. This quantifies the data-linkage limitation.
Time frame: Index hospitalisation, up to 5 days
Plan to share: Yes — Anonymous study data will be shared via https://www.adp.fdv.uni-lj.si
Supporting information: Study protocol, Analytic code
Time frame: 1 year
Access criteria: Approval by ADP
Start is estimated for Oct 2026; primary completion for Oct 2027, 12 months later.
Of 237 non-industry observational studies under Acute Coronary Syndrome, half reached primary completion within 37 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 71. This study's planned 12 months is below that.
Counting every sponsor, half of 274 studies reached it within 35 months; a quarter within 18 and three quarters within 68.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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University Medical Centre Maribor