Vol. 6, Issue 1, Part A (2024)

Objective: Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) is the presence of the universal acute myocardial infarction (AMI) criteria, stenosis less than 50%, and no overt cause for the clinical presentation at the time of angiography. Diagnosis of MINOCA may require multiple diagnostic tools, including cardiac imaging or provocative tests, in addition to standard coronary angiography, according to clinical suspicion. The aim of this study is to assess the prevalence and predictors of myocardial infarction with non-obstructive coronary arteries in Egyptian patients.
Methods: This prospective and observational study was conducted in Tanta university hospital and El Zeitoun specialized hospital from April 2022 till April 2023. All patients who were ≥18 years old, diagnosed with MI according to the Fourth Universal Definition of Myocardial Infarction, and undergone Coronary Angiography included in the study while patients with history of revascularization (PCI or CABG) or diagnosed as MI type 4 or 5 excluded from our study. 
Results: 844 patients diagnosed with MI and had undergone CA were screened between April 2022 and april 2023. The prevalence of MINOCA was 8.06% (n=68) in our study. MINOCA patients were found to be younger, had a higher incidence of the female gender. MINOCA patients has lower incidence of risk factors such DM, HTN, smoking and dyslipidaemia (p<0.05, for all). ST elevation ECG is significantly higher in OCA-MI than in MINOCA. WBCs, neutrophils and CKMB level was higher in OCA-MI patients than MINOCA patients (p<0.001), While MINOCA patients have higher systolic and diastolic BP at presentation with Killip class less than 2 (p<0.001). Also, the mean left ventricular ejection fraction by the echocardiography was significantly higher in MINOCA patients (p<0.001), While OCA-MI patients have more dilated LVEDD, LVESD and higher incidence of both WMA and LV thrombus (p<0.001). Patients with MINOCA has lower range of hospital stay (p<0.001), less liable to worse in hospital outcome such as complete heart block, LV thrombus, temporary pacing and heart failure development (p<0.05). 
The culprit of MI in was found to be LAD in 369 patients, LCx in 116, RCA in 237 patients, OM in 36 patients and LM in 18 patients. While coronary angiography in MINOCA group normal in 36 patients, ectasia in 9 patients, dissection in 8 patients, myocardial bridge in 3 patients and slow flow in 12 patients
Conclusion: The prevalence of MINOCA in our study is 8.06% in patients who were admitted with MI. Also, as compared to OCA-MI patients, the MINOCA patients are younger, more female incidence, have fewer traditional factors and more benign inhospitable course.