Myocardial infarction with non obstructive coronary arteries (MINOCA) according to definitions of 2020 ESC Guidelines: clinical profile and prognosis
Authors: Nieto Ibanez D , Fraile Sanz A , Izquierdo Coronel B , Perela Alvarez C , Olsen Rodriguez R , Abad Romero R , Galan Gil D , Espinosa Pascual M , Moreno Vinues C , Lopez Pais J , Awamleh Garcia P , Mata Caballero R , Alonso Martin J J ,   IMACORN Group
Published: October 2021

Abstract

Background
MINOCA's physiopathology, treatment and prognosis are yet to be completely understood. The aim of this study is to compare baseline characteristics and prognosis of MINOCA patients and those of patients with myocardial infarction (MI) and obstructive coronary arteries.

Methods
We analysed all consecutive patients with MI who underwent coronary angiography admitted in a University Hospital covering a population of 220.000 people during a period of 60 months. The database and the all the patient's angiographies were revised by a group of experts in order to adequate MINOCA to 2020 ESC Guidelines definition and the American Heart Association position paper.

Results
680 patients, 68 of whom were MINOCA (10%) with a median of follow up of 31±16 months were analysed (see table 1). We found no differences in both groups' age. Female gender was more prevalent among MINOCA patients. The underlying mechanism in MINOCA was coronary spasm (17.6%), plaque rupture (13.2%), coronary embolism (7.4%), coronary dissection (2.9%), type II infarction (19.1%) or unknown (39.7%). Coronary arteries in MINOCA patients had no obstructions at all in 57.4%, and 30–50% obstruction in 42.6% of the cases. MINOCA patients didn't have higher prevalence of cancer, autoimmune or psychiatric diseases, dyslipidaemia, hypertension or inflammatory analytical parameters. However, we found significant differences in atrial fibrillation, migraine, connective tissue diseases, tobacco use and diabetes. We found no effect of stress in the development of MINOCA (measured with validated STAI and DS-14 scales). Symptoms at admission didn't differ between the two groups, but those with MINOCA had normal ECG more frequently. Prognosis showed relevant differences, as MINOCA patients had less major cardiovascular complications, such as inotropic requirements (0% Vs 4.8%, p=0.04), shock (0% vs 6.6%, p=0.013) and left ventricular dysfunction (11.8 vs 30.2, p=0.015). Furthermore, myocardial injury biomarkers' levels were, significantly lower in MINOCA patients. Death rates tend to be lower both in hospital (0% vs 3.1%, p=0.131) and during follow up (9.1% vs 11.5%, p=0.369).

Conclusion
Analysing MINOCA patients' clinical profile might help us understanding the underlying physiopathology, prognosis and treatment targets. In these patients, classic cardiovascular risk factors don't appear to be as important as in obstructive patients. At admission, we found no clinical differences that could help making an early diagnosis, even if those with normal ECG and lower levels of myocardial injury biomarkers are more likely to have non-obstructive coronary arteries. These patients seem to have better prognosis and lower myocardial injury than those with obstructive coronary arteries. Further research is needed to provide more evidence on the accurate treatment of these patients.

Funding Acknowledgement
Type of funding sources: None.