ИСТИНА

This study aimed to identify a relationship between blood microcirculation parameters (MP) and endothelial function (EF) in healthy volunteers and two groups of patients suffering from cardiovascular diseases, specifically coronary heart disease (CHD) and atrial fibrillation (AF). These diseases pose significant health risks and require accurate diagnostic tools to assess the severity and progression of the diseases. Traditional diagnostic methods have limitations in providing detailed information about blood flow characteristics, particularly in the microcirculation. Digital optical capillaroscopy was employed to assess such MP as blood flow velocity, the size of red blood cell aggregates, and the number of aggregates per min and per running mm measured in the finger nail bed capillaries of the subjects included into the study groups. The digital capillaroscope Kapillaroskan-1 (AET, Russia) was utilized to visualize the capillaries. It was equipped with a high-speed CCD-camera (1/3″ monochrome progressive scan IT CCD sensor, resolution 640 × 480 px, frame rate 200 fps full frame), specifically the TM-6740GE (JAI, Japan). The illumination of the nail bed was achieved using an LED-based illuminating system. Two sets of total magnification were employed: 125× and 400×. The 125× magnification was used to capture panoramic images of the capillaries, facilitating the selection of higher quality images among capillaries in the nail bed, while the 400× total magnification allowed for more detailed imaging of individual capillaries. This higher magnification also facilitated the measurement of static parameters such as capillary length and diameter in various parts of the capillary, as well as the assessment of capillary blood velocity in different capillary segments. To quantitatively estimate the EF we used the experimental device “Angiochek” (Russia), in which the method of pulse tonometry was implemented. Highly sensitive acoustic sensors located in the projection of the brachial artery and wrist arteries were used for measuring the amplitudes of pulse waves of the arteries. The study of microcirculation involved 132 adults including 44 healthy volunteers, 44 patients with CHD and 44 patients with AF. The measurements were performed in three groups for comparison: control group (healthy volunteers), group of patients with CHD and group of patients with AF. An additional study of the correlation between MP and EF included 47 adults extracted from an initial sample of 132 adults for whom EF was measured. Patients with AF, as well as CHD patients presented in this study, take oral anticoagulants (mainly apixaban and rivaroxaban) according to the protocol adopted by the cardiology department. The results indicate significant alterations in blood flow characteristics among patients with CHD and AF compared to healthy volunteers [1]. For example, capillary blood flow velocity is statistically significantly decreased in the case of CHD and AF compared to the healthy volunteers. Additionally, the correlation between the measured parameters is different for the studied groups of patients and healthy volunteers. The correlation between the MP and the EF is higher for the patients with CHD. Specifically, an increase in EF measured on the wrist leads to a significant decrease in the blood aggregate size. These findings highlight the potential of digital optical capillaroscopy as a non-invasive tool for evaluating blood flow abnormalities (red blood cell aggregates and decreased capillary blood flow velocity) in cardiovascular diseases, aiding in early diagnosis and disease management. This research was funded by the Russian Science Foundation Grant No. 22-15-00120.