Clinical characteristics and prognosis of myocardial infarction with non-obstructive coronary arteries: A prospective single-center study

Background: A definition of myocardial infarction with non-obstructive coronary arteries (MINOCA) was published by European Society of Cardiology in 2016. The aim of this study is to analyze the clinical profile and prognosis of these patients in a prospective single-center study and compare it with the literature data.

Methods: During a 3-year period, information from every consecutive MINOCA patient was gathered (n = 109). It was then compared with 412 contemporaneous patients with myocardial infarction and obstructive coronary arteries (MIOCA). Univariate and multivariate analyses were performed. Prognosis analysis was adjusted by age and cardiovascular risk factors (CVRF).

Results: MINOCA represented 16.9% of the total of patients admitted for myocardial infarction (MI). Compared with MIOCA, they had more psychosocial disorders (22.9% vs. 10.7%; p < 0.01) and more pro-inflammatory conditions (34.9% vs. 14.0%; p < 0.01). Atrial fibrillation was twice as frequent in MINOCA (14.7% vs. 7.3%; p = 0.016). Predictors of MINOCA were as follows: female gender, absence of diabetes, absence of tobacco use, tachycardia, troponin above 10 times the 99th percentile, and proinflammatory conditions. Median follow-up was 17.3 ± 9.3 months. Major adverse cardiovascular events (MACE; a composite of a recurrence of acute MI, transient ischemic attack/stroke, or death from cardiovascular cause and death from any cause) occurred in 10.8% of the MINOCA group as compared with 10.7% in the MIOCA group (hazard ratio [HR] 1.19, 95% confidence interval [CI] 0.58-2.45; p = 0.645). Cardiovascular re-admission rates were higher in the MINOCA group: 19.8% vs. 13.9% (HR 1.85; CI 1.06-3.21; p = 0.030).

Conclusions: The frequency of MINOCA is high, with fewer CVRF, and it is linked to atrial fibrillation, psychosocial disorders, and pro-inflammatory conditions. Mid-term prognosis is worse than previously thought, with a similar proportion of MACE as compared to MIOCA, and even a higher rate of cardiovascular re-admissions.