Prevalence and Clinical Characteristics of Myocardial Infarction With Non-obstructive Coronary Arteries Compared With Obstructive Myocardial Infarction: A Retrospective Tertiary-Centre Study

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a working diagnosis in patients who fulfil the diagnostic criteria for acute myocardial infarction (AMI) but have no coronary artery stenosis ≥50% and no clinically evident alternative diagnosis that adequately explains the presentation.It encompasses heterogeneous coronary mechanisms.Objective: To determine the prevalence and clinical characteristics of MINOCA at a tertiary cardiac centre in Bosnia and Herzegovina and to compare demographic characteristics, cardiovascular risk factors, electrocardiographic presentation, laboratory parameters and echocardiographic findings with those of patients with obstructive myocardial infarction (OMI).Methods: This retrospective single-centre observational study comprised a prevalence analysis and a comparative analysis.For the prevalence analysis, medical records of 2,341 patients admitted to the Intensive Cardiac Care Unit between April 2022 and February 2024 were reviewed, of whom 1,104 fulfilled the diagnostic criteria for AMI.For the comparative analysis, 40 patients with MINOCA identified between January 2020 and February 2024 were compared with a simple random sample of 155 eligible patients with OMI.Demographic characteristics, cardiovascular risk factors, electrocardiographic presentation, laboratory parameters and echocardiographic variables were analysed.Results: MINOCA accounted for 32 (2.9%) MIs in the prevalence analysis.Patients with MINOCA (N = 40) were younger than patients with OMI (N = 155) (52.1 ± 15.2 vs. 59.8 ± 11.7 years; p = 0.005).Among patients with available sex data, female sex was more frequent in the MINOCA group (19 {47.5%}) than in the OMI group (43 {29.9%}; p = 0.037).The MINOCA group had a shorter hospital stay and a lower prevalence of hypertension, dyslipidaemia and active smoking.Diabetes mellitus was numerically less frequent, but the difference was not statistically significant.MINOCA more frequently presented as non-ST-elevation myocardial infarction (NSTEMI; 19 {51.4%} vs. 20 {13.9%}; p < 0.001) and was characterised by lower peak troponin T and CK-MB concentrations, higher left ventricular ejection fraction and a lower wall motion score index.Conclusion: MINOCA should be approached as a heterogeneous working diagnosis rather than a uniform final diagnosis.The absence of obstructive coronary artery disease should prompt continued clinical evaluation and a structured, individualised diagnostic approach.Standardised diagnostic pathways and prospective multicentre studies incorporating comprehensive imaging and long-term clinical follow-up are needed to refine risk assessment and guide management.