Relationship between free circulating DNA levels, ejection fraction and brain natriuretic peptide levels in patients with chronic heart failure: prospective observational study

BACKGROUND: Chronic heart failure (CHF) is one of the most serious problems in cardiovascular diseases, requiring accurate diagnosis and treatment. The search for new laboratory markers of CHF can improve the accuracy of diagnosis and identify the severity of the patients condition. AIM: Our aim was to study the relationship between the levels of free-circulating DNA (cfDNA) and brain natriuretic peptide (NT-proBNP) in the blood plasma of patients suffering from CHF with ejection fraction (EF), to investigate the relationship between these laboratory markers, and to evaluate the dynamics of changes in the studied parameters against the background of drug therapy. MATERIALS AND METHODS: The study involved 67 patients of both sexes with a diagnosis of CHF, verified by clinical and functional methods. 23 people without established chronic diseases formed the control group. At the stage of inclusion in the study, all patients underwent: physical examination, general blood test, biochemical blood test with determination of lipid profile, glucose, creatinine, NT-proBNP and cfDNA levels, as well as electrocardiography (ECG), electrocardiography (ECHO-CG), radiography of organs chest, ultrasound of the abdominal organs, 6-minute walk test. The level of cfDNA was determined using the method of P.P. Laktionov, S.N. Tamkovich, E.Yu. Rykova (2005). Repeated blood sampling with assessment of cfDNA and NT-proBNP levels was carried out in the group of patients with reduced ejection fraction 57 months from the start of treatment/correction of previous therapy. RESULTS: The study revealed significant differences in the levels of cfDNA in the blood plasma in patients with different EF (less than 40%, 4049%, 50% or more). At the same time, an inverse relationship was established between cfDNA indicators and EF, as well as between the level of NT-proBNP and EF, that is, a progressive decrease in myocardial contractility is accompanied by a combined increase in the levels of the studied markers in the blood, reflecting the severity of the patients condition. In addition, the positive effect of drug therapy on cfDNA and NT-proBNP levels in the group of patients with EF 40% has been proven. CONCLUSION: The identified patterns make it possible to consider the level of cfDNA in blood plasma as a potential biomarker of CHF, and also to use it for dynamic monitoring of patients.