Diagnostic and clinical significance of cell free DNA levels in patients with chronic heart failure

BACKGROUND: Chronic heart failure CHF remains one of the main causes of disability in patients with cardiovascular diseases. Leading to the development of persistent dysfunctions of the entire body, CHF significantly reduces the quality of life and worsens the patient’s prognosis. Therefore, it is so important to promptly identify the disease and carry out optimal therapy, which will delay the onset of irreversible consequences.

AIM: Analysis of cell free DNA level of in the blood plasma in patients with chronic heart failure and identification of differences in the studied indicator depending on the clinical characteristics of the patient.

MATERIALS AND METHODS: The study included 67 patients diagnosed with chronic heart failure and 23 healthy volunteers who were in satisfactory health, who made up the comparison group. All subjects underwent a gender and age assessment, analysis of risk factors, anthropometric indicators with calculation of body mass index. In patients with CHF, clinical and biochemical blood tests were performed to determine NT-proBNP, lipid profile, glucose and creatinine; In addition, an instrumental examination was performed, including electrocardiography, echocardiography, fundus examination, ultrasound examination of the abdominal organs, chest radiography, and a 6-minute walk test to assess the functional class. The level of cell free DNA was determined according to the method of P.P. Laktionova, S.N. Tamkovich, E.Yu. Rykova (2005). In the study group of patients, the causes of CHF development were analyzed, and the presence of a history of myocardial infarction and its duration were separately taken into account.

RESULTS: The study established the average level of cell free DNA for patients with CHF (273.5±25.26 ng/ml) and in the comparison group (53.7±3.5 ng/ml), which is a statistically significant difference (p=0,00). Analysis of the causes of chronic heart failure revealed a combination of coronary heart disease and arterial hypertension as the main etiological factor; the number of patients in the study group was 58%. A decrease in exercise tolerance, revealed during the 6 minute walk test, is accompanied by an increase in the level of cell free DNA in the blood, with a progressive increase in concentration from functional class I (141.9±26.3 ng/ml) to functional class III (447.7±51.7 ng/ml). Among patients suffering from coronary artery disease, a history of myocardial infarction leads to an increase in the level of free circulating DNA by almost 2 times compared with patients with a stable course of coronary heart disease. Also, the level of free circulating DNA depends on the duration of acute myocardial infarction, demonstrating a significant difference between the early (440.8±87.6 ng/ml) and late recovery period (225.5±46.5 ng/ml).

CONCLUSION: Significant differences in cell free DNA levels were revealed between the group of patients with CHF and the control group, which allows us to consider this marker as a potential diagnostic criterion for CHF