Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA): A Case Report and Review of the Literature

: Background : About 5-10% of all myocardial infarction patients undergoing diagnostic coronary angiography for typical chest pain have no significant coronary stenosis (stenosis severity <50%). We classified these patients as myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA), which is characterized by both the diagnostic criteria of myocardial infarction and no significant coronary stenosis (stenosis severity <50%). The pathophysiology of MINOCA is multifactorial. Potential underlying mechanisms of MINOCA include coronary causes such as coronary spasm, coronary microvascular dysfunction, plaque disruption, spontaneous coronary thrombosis/emboli, and coronary dissection; myocardial disorders, including myocarditis, takotsubo cardiomyopathy, and other cardiomyopathies; and noncardiac causes, for example, pulmonary embolism. Early secondary prophylaxis with drugs including statins and renin-angiotensin-aldosterone system inhibitors may be beneficial to prognosis. Objective : To report a case of MINOCA, analyze its clinical manifestations, imaging and related treatment, and improve the understanding of clinicians on MINOCA. Methods : A case of MINOCA diagnosed in the First Hospital of Hebei Medical University on June 8, 2021 was retrospectively analyzed. Clinical data related to clinical manifestations, examination results, diagnosis and treatment process were collected, and literatures related to non-obstructive myocardial infarction were reviewed to summarize its diagnosis and treatment characteristics. Results : The patient was a 73-year-old male, who was admitted to hospital for 8 hours due to sudden precardiac pain. After admission, relevant preoperative examination was completed, and preoperative electrocardiogram (ECG) and troponin examination results were considered as acute inferior wall myocardial infarction, percutaneous coronary angiography showed no significant narrowing of the coronary vessels and was diagnosed as MINOCA. The patient regularly applied drugs outside the hospital and was generally in good condition. He did not go to the hospital again. Conclusion : 1. MINOCA accounts for 5-10% of all MI patients, and a higher proportion of MINOCA patients are female. 2. It was previously believed that MINOCA patients had a good prognosis, but the incidence of major adverse cardiovascular events was still high in clinical work. The pathogenesis of MINOCA is complex and diverse, and early drug intervention and secondary prevention targeting the etiology can improve the prognosis of patients. 3. The clinical manifestations and characteristics of MINOCA patients were summarized in this case, the possible pathogenesis and treatment, so as to improve the understanding of this disease, screen high-risk groups for early intervention, and reduce the risk of adverse cardiovascular events in these patients.