MINOCA: under recognized and affecting predominantly female patients-an Australian experience.

Background: Myocardial infarction with nonobstructive coronary arteries (MINOCA) is now being recognized as an important clinical entity with prognostic implications. There are limited data in relation to MINOCA in our local Australian settings.

Aim: We investigated the prevalence, clinical characteristics, major adverse cardiovascular events (MACE), and 1-year mortality of patients with MINOCA at Peninsula Health.

Method: A single-center retrospective study of all adult patients aged ≥ 18 years who underwent invasive angiography from January 2018 to June 2020 was identified from medical records. We included patients who met the definition of MINOCA as per the 2019 AHA Statement. A simple descriptive statistical analysis was performed.

Results: The prevalence of MINOCA at Peninsula Health was 10.9% (131/1199) with a median age of 62 (IQR 53-74). Female patients were predominant, comprising 64% (84/131) of these patients. Chest pain was the most common symptom in 92.3% (121/131) and 58.8% (77/131) had ECG changes. A total of 81% (106/131) had a normal left ventricular systolic function and 47% of patients (66/139) had no luminal disease on invasive angiography. A total of 15.9% (23/144) of patients with an initial working diagnosis of MINOCA were referred for CMR on discharge. MACE was 5.2% (6/115) over a median follow-up of 23 months. The all-cause mortality rate at 1 year was 0.7% (1/131).

Conclusion: The clinical prevalence rate of MINOCA at Peninsula Health is 10.9% with a MACE of 5.2%. MINOCA is recognized and the low rate of additional testing could be improved given the female predominance and prognostic implications.