Impaired blood fat metabolism and chronic inflammation are intertwined as possible causes of atherosclerosis. Lipoprotein (a) (Lp (a)) is a specific subfraction of lipoprotein that is an independent risk factor for coronary heart disease and at the same time predicted residual risk in patients with pre-existing atherosclerosis, regardless of serum LDL-cholesterol concentration. Circulating levels of Lp(a) are mainly genetically determined and varies according to ethnic group. Lp(a) has many functions, which include atherosclerotic, prothrombotic and pro-inflammatory roles. The gene encoding apo (a); LPA, is located on the long arm of chromosome 6 (6q2,6-2,7) and most variants in Lp (a) can be explained by genetic diversity in LPA. To date, the most studied genetic variant is the Kringle-IV type-2 (KIV2) polymorphism, which explains 30-70% of the diversity in Lp (a) in the population. Some KIV2 replicates are associated with smaller isoforms and higher plasma concentrations of Lp (a) which are causally and independently associated with coronary heart disease. Within LPA, the number of KIV2 copies, as well as one nucleotide polymorphism (SNP), rs3798220 and rs10455872, is associated with Lp (a) concentration and coronary heart disease. Recently 'Proprotein convertase subtilisin/kexin type 9' (PCSK9) inhibitors that act through non-specific reduction of Lp(a) are the only drugs that have shown effectiveness in clinical trials, to provide reductions in cardiovascular morbidity and mortality. The effects of PCSK9 inhibitors are not purely through Lp(a) reduction, but also through LDL cholesterol reduction.
The early stage of the atherosclerosis process is characterized by endothelial cell damage, which results in impaired release and function of nitric oxide (NO) from the endothelium. NO is formed by endothelial NO synthetase (NOS-3) from the amino acid L-arginine, which is most pronounced in the vascular wall and is also most important in the process of atherosclerosis. The NOS-3 gene is located on chromosome 7; in the region 7q35-7q36. Functional polymorphisms are those that alter the expression or activity of NOS-3. Among them, rs2070744, rs3918226 and rs1799983 single nucleotide polymorphisms (SNP) are important. Variations in the expression and activity of NOS-3 genetic polymorphisms at exon 7 of the NOS-3 gene are associated with the incidence of myocardial infarction in very young patients who otherwise have a low atheromatous coronary artery load. Variations in the NOS-3 genes cause diversity in NO bioavailability and are responsible for endothelial dysfunction.
A 6-month observational, prospective, and randomized study will include 70 patients with a first acute coronary syndrome (ACS) (including acute transmural myocardial infarction, nontransmural myocardial infarction or unstable angina pectoris) event before age 55 and Lp (a) levels above 1000 mg / L or Lp (a) above 600 mg / L and LDL above 2.6 mmol / L. With the gradual inclusion ("step-wedge") and randomization of patients, the investigators will also provide a control group that will include 30 patients. The investigators will do anamnesis, targeted clinical examination, take blood samples for laboratory measurements, ultrasound measure endothelium-dependent dilatation of the brachial artery and intima media thickness of carotid arteries, measure pulse wave and calculate carotid artery wall stiffness. Patients will be divided into three groups according to a randomization list. The first group will receive alirocumab, the second group evolocumab, and the third group will be the control group and will be included in the treatment after 6 months. During this time, the control group will not receive treatment with alirocumab or evolocumab, only standard treatment. After 6 months, the investigators will repeat all the mentioned investigations. Patients will be informed about the purpose and course of the study before starting it. All will participate voluntarily, without pressure or inappropriate instigation, which they will confirm by signing.
The investigators hypotheses that in patients with early coronary artery disease Lp (a) and Lp (a) polymorphisms are associated with indicators of inflammation and structural-functional properties of the arterial wall; in patients with early coronary artery disease, PCSK9 inhibitors reduce the value of Lp (a), indicators of inflammation and structural and functional involvement of the arterial wall; in patients with early coronary artery disease, the influence of PCSK9 inhibitors on Lp (a), indicators of inflammation and structural-functional properties of the arterial wall depends on the presence of specific polymorphisms for Lp (a).
