Background: Acute myocardial infarction (AMI) with no evidence of relevant stenosis of the coronary artery, known as myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA), has a prevalence of up to 14%. The various causes of MINOCA lead to damage of the myocardium, and there are marked differences in diagnoses, prognoses, and treatments. Although the number of patients affected is considerable owing to the high prevalence of acute coronary syndrome (ACS), the causes of MINOCA have received little attention with the result that some patients may not receive appropriate treatment. Awareness of this disease among clinicians has started only to improve since the beginning of the current century. The aim of this study was to develop a score that enables patients with MINOCA to be distinguished from patients with MI with coronary artery disease (MI-CAD) and thus to facilitate appropriate diagnosis and therapy.
Patients and methods: A multicenter observational cohort study was designed. All patients aged ≥18 years from the ARIAM-SEMICYUC (Analysis of Delay in AMI-Spanish Society of Intensive Care Medicine and Coronary Unit) registry, diagnosed with AMI, and admitted to critical care units or coronary care units (CCUs) were included. Patients were classified into two groups: MINOCA, comprising patients with no significant lesions on angiography, and MI-CAD, comprising patients with lesions of the coronary artery tree.
Results: A score based on standard variables to assess the probability of MINOCA on admission was designed, showing a maximum value corresponding to a 40% probability of MINOCA. The discriminative power of the model was 0.756 (P-value for the Hosmer-Lemeshow test was >0.05). At 30-day follow-up, the mortality rate was higher for MI-CAD patients.
Conclusion: Patients with MINOCA constitute a population that differs from other patients with AMI. Their differential characteristics require a certain diagnostic effort to align therapy with the disease causing the ischemic event. This score could prove useful in establishing additional diagnostic procedures.
Keywords: MINOCA; acute myocardial infarction; coronary syndrome; nonobstructive coronary disease; score.