Evaluation of the endothelial function, and elasticity of vessel walls and their influence on the 1-year prognosis of patients with myocardial infarction with obstructive and non-obstructive coronary arteries

Aim. This study was conducted to analyze the state of the endothelial function (EF) and elasticity of vessel walls and their influence on the 1-year prognosis of patients with myocardial infarction (MI) with obstructive and non-obstructive coronary arteries (CA) comparatively.

Materials and Methods. At the first stage, 206 patients diagnosed with MI were selected. Among them, 103 patients had MI with non-obstructive CA (MINOCA) as indicated by coronaroangiography, and 103 patients had MI with obstructive CA (MIOCA). Through the random number method, 59 patients were selected (34 patients in the first group and 25 patients in the second group), and the EF and elastic properties of their arterial walls were evaluated. The patients in both groups were initially comparable in terms of age, gender, clinical, and medical history and the frequency of application of the main groups of medical drugs that influenced prognosis. The 1-year prognosis of the two groups of patients was studied on the basis of the presence/absence of the functional and morphological alterations of the vessel wall.

Results. The evaluation of the EF of patients with MINOCA showed that the occlusion index by amplitude (OIA) was below the threshold values in 22 of 34 (64.7%) cases of MINOCA and 22 of 25 (88.0%, р<0.05) cases of MIOCA. Their average values of OIA were 1.7 (1.5; 2.3) and 1.4 (1.2; 1.8), respectively (р<0.05). The values of the phase shifts between the channels below the norm were equally frequent in the two groups (88.2 and 88.0%, р>0.05). The comparison of the average values of this parameter did not show any statistically significant difference. The calculated augmentation indices normalized to the pulse rate of 75 beats per min (AIp75) in the study groups were 12.5 (9.9; 17.9) and 18.8 (12.9; 20.8), respectively (р>0.05). The elasticity of the vessel wall decreased in 82.4% of patients with MINOCA and 100% of patients with MIOCA (р<0.05). The frequency of cardiovascular events did not significantly differ between the groups for 1 year (р>0.05).

Conclusion. Functional changes in the vessel walls (endothelial dysfunction and reduction of vessel wall elasticity) of patients with MINOCA were recorded in almost 2/3 of the cases; however, the incidence in patients with MIOCA was still higher (88.0%) than that in patients with MINOCA. The 1-year prognosis in the study groups had no differences.