A cohort study: Myocardial infarction with non-obstructive coronary arteries (MINOCA) in an Irish tertiary centre

Myocardial infarction with non-obstructed coronary arteries (MINOCA) represents a diagnostic and therapeutic challenge. Approximately 10% of patients presenting with acute MI do not have obstructive coronary artery disease on coronary angiogram as confirmed in several large Acute Myocardial Infarction (AMI) registries. A diagnosis of MINOCA can be introduced in patients with consistent features of MI and demonstrated nonobstructive coronary artery disease. With increased utilisation of coronary angiograms and high sensitivity troponin, the identification of MINOCA is encountered more frequently. The long-term clinical outcome and prognosis of this subgroup is not well known or understood. The aim of this retrospective cohort study was to evaluate patient demographics, diagnosis and the 12-month follow-up of 26 inpatients who presented with MINOCA in an Irish tertiary centre. The following inclusion criteria was used in the definition of MINOCA; elevated troponin biomarkers, clinical features of ischaemia (symptoms, ischaemic changes on electrocardiogram, new loss of viable myocardium or wall motion abnormality) evidence of intracoronary thrombus or a non-obstructive pattern angiographically. Acute myocarditis was the most common cause of MINOCA with unobstructive angiography in this cohort of patients. 15.3% (n=4) had a recurrent hospital admission with similar presentation within 12 months of the primary event. Establishing appropriate diagnosis and identifying patient risks is essential to ensure patients receive both preventative therapy and appropriate treatment.