Importance of confirming the underlying diagnosis in patients with myocardial infarction and non-obstructive coronary arteries (MINOCA): a single-centre retrospective cohort study

BackgroundMany patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) are discharged without a known aetiology for their clinical presentation. This study sought to assess the effect of this 'indeterminate MINOCA' diagnosis on the prevalence of recurrent cardiovascular events and presentations to the Cardiac Emergency Department (CED).MethodsWe retrospectively analysed all patients meeting the diagnostic MINOCA criteria presenting at a large secondary hospital between January 2017 and April 2019.ParticipantsPatients were divided into the (1) 'indeterminate MINOCA', or (2) 'MINOCA with diagnosis' group. The primary outcome was the occurrence of major adverse cardiac events (MACE) defined as the composite of all-cause mortality, non-fatal myocardial infarction, stroke and any revascularisation procedure. Secondary outcomes were all recurrent visits at the CED, and MACE including unplanned cardiac hospitalisation.ResultsIn 62/198 (31.3%) MINOCA patients, a conclusive diagnosis was found (myocardial infarction, (peri)myocarditis, cardiomyopathy, or miscellaneous). MINOCA patients with a confirmed diagnosis were younger compared to those with an indeterminate diagnosis (56.7 vs. 62.3 years, p=0.007), had higher maximum troponin-T [238 ng/L vs. 69 ng/L, p