Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) means a non-negligible proportion of patients (pts) admitted for MI. However, there are still unsolved questions about this entity. The aim of our study is to analyse the differences between the MINOCA group compared with pts admitted for MI with obstructive coronary disease.
Analytical and observational study developed in a Universitary Hospital, which covers 220.000 individuals. From january-2016 until december-2018 we reviewed all the pts that were admitted for MI who underwent coronariography. MINOCA pts (defined according 2016 ESC Working Group position paper) compared with MI pts with obstructive lesions.
One hundred and nine from 521 pts admitted for MI in whom a coronariography was performed fulfilled the 2016 ESC criteria of MINOCA (20%). Clinical presentation showed no difference in Killip-Kimball classification (K-K > I was 6.1% in MI with obstructive lesions vs 6.5% in MINOCA pts, p 0.897). Chest pain (Angina) was more frequent in MI with obstructive lesions (82.8% vs 73.4%, p 0.027) and they also had more ST changes (ST elevation 41% vs 24%, p 0.001; ST descent 17% vs 8.3%, p 0.026). MINOCA pts had lower levels of troponine (troponine elevation less than 10 times the 99th percentile: 10.4% vs 26.6%, p <0.001). Left ventricular systolic dysfunction showed no difference neither in the % of pts with ejection fraction lower than 50% (MI with obstructive lesions: 32% vs MINOCA: 34.3%, p 0.659) nor in severe systolic dysfunction (ejection fraction lower than 30%: 4.9% in MI with obstructive lesions vs 7.4% in MINOCA pts, p 0.313). The average stay in MI pts with obstructive lesions was 12.6 days vs 8.9 days in MINOCA pts (p 0.274). Complications during hospital admission occurred in 17.6% of obstructive pts and in 13.8% of MINOCA pts (p 0.335). Only one MINOCA pts (0.9) died during admission compared to 3.4% of MI pts with obstructive lesions, being this result statistically non significant (p 0.213).
Although MINOCA pts have lower troponine levels and less severe alterations on the EKG, we did not find differences regarding left ventricular function and the rate of complications with hospital mortality that tended to be higher in patients with obstructive lesions.