Differences between MINOCA and type 2 myocardial infarction: An ITALIAN observational study

Myocardial infarction with non-obstructive coronary arteries (MINOCA) and type 2 myocardial infarction (MI), both presenting as non-ST-elevation MI (NSTEMI), are often grouped together due to overlapping symptoms. The aim of our study is to compare their characteristics and prognosis to distinguish between them.

Among 7815 patients with NSTEMI who underwent coronary angiography between 2005 and 2022 we identified 538 patients with diagnosis of MINOCA (n = 301; 3,9 %) and type 2 MI (n = 237; 3 %). The outcome was a composite of all-cause mortality, non-fatal MI, hospitalisation for heart failure (HF) and transitory ischemic attack or non-fatal stroke.

The mean age of the entire cohort was 68 (11.5) years, with women being the most frequently represented group (65 %). Comparing the sub-cohorts, MINOCA patients were younger (66.3 (11.7) Vs. 70.6 (11) years, p < 0.01), and less likely to have typical cardiovascular risk than type 2 MI patients. At multivariable analysis different clinical (age, heart rate, typical chest pain, palpitations, postmenopausal status), and instrumental (cardiac rhythm, ST-segment changes, diastolic dysfunction, hypo/akinesia with non-coronary distribution) variables were independent predictors of MINOCA with AUC of 0.83 [95 % CI, 0.78-0.88], p < 0.01 at ROC analysis. At a median follow-up of 61 (IQR 34-100) months, MINOCA patients had significantly lower rate of the composite endpoint compared to type 2 MI (20 % Vs. 32 %, p < 0.01).

MINOCA cohort was associated with different characteristics compared to type 2 MI and had a better prognosis despite the number of events was not negligible.