Clinical, Laboratory and Instrumental Characteristics of Myocardial Infarction in Young Patients Depending on the Prevalence of Coronary Atherosclerosis

<i>Background and Objectives</i>: To study the clinical/anamnestic, laboratory and instrumental characteristics, as well as the tactics of treatment, of myocardial infarction (MI) in young patients, depending on the number of affected coronary arteries (CAs), including patients with non-ST elevation myocardial infarction. <i>Materials and Methods</i>: A single-center retrospective study was conducted based on data from 374 patients under 44 years of age who had experienced myocardial infarction (MI) between 2015 and 2023. The patients were divided into groups according to coronary angiography findings: those without obstructive lesion and those with single-vessel, two-vessel, and multi-vessel disease. Standard methods of statistical analysis were applied. <i>Results</i>: A pronounced predominance of men (91.2%) and a high prevalence of modifiable risk factors were identified. The most frequent finding was single-vessel disease (41.9%); however, a significant proportion of patients had two-vessel (25.7%) and multi-vessel (18.2%) CA disease. MI without obstructive CA lesions was diagnosed in 4.3% of patients. Patients with multi-vessel disease had statistically significantly higher levels of total cholesterol and low-density lipoproteins, as well as signs of more pronounced structural cardiac remodeling. <i>Conclusions</i>: MI at a young age is associated with a high prevalence of modifiable risk factors and a significant proportion of extensive atherosclerosis. The identification of a group without obstructive CA lesions (4.3%) underscores the heterogeneity of myocardial infarction pathogenesis in the young and the need to account for it in the diagnostic algorithm. The obtained data confirm the necessity of enhancing primary and secondary prevention programs.