The aim of the study. To assess the dynamics of neurovegetative disorders in patients with coronary artery disease (CAD) with Long COVID-19 syndrome under the influence of combined treatment with the inclusion of exogenous L-arginine and phenibut in basic therapy.

Materials and methods. A prospective study with parallel distribution and elements of randomization included 31 patients with CAD: stable angina of exertion of functional class II–III (age 69.0 (64.0; 76.0) years)), who had suffered from moderate or severe COVID-19 coronavirus disease with manifestations of Long COVID-19 syndrome. Patients were divided into two groups depending on the prescribed treatment: group I (n = 15) – basic therapy for CAD was used; in group II (n = 16) a combination of L-arginine and phenibut was additionally prescribed against the background of basic therapy. Heart rate variability (HRV) parameters were assessed using 24-hour Holter ECG monitoring, degree of cognitive impairment – MoCa scale, anxiety-depressive – HADS scale, as well as their dynamics under the influence of the treatment.

Results. The use of combination therapy with the inclusion of exogenous L-arginine and phenibut in patients of group II contributed to an increase in the average integral indicator of cognitive status by 9.47 %, as well as a significant decrease in the level of anxiety-depressive symptoms: in the “Anxiety” subscale by 35.97 %, in the “Depression” subscale – by 20.81 % (p < 0.05). In the group receiving combination therapy with exogenous L-arginine and phenibut, a significant positive dynamics of most indicators of total HRV was determined: an increase in SDNNi by 1.22 times and 1.42 times, rMSSD, % by 1.56 times and 1.66 times, HRVT by 1.46 times and 1.40 in the daytime and nighttime periods, respectively. Analysis of HRV spectral indicators showed restoration of sympatho-parasympathetic balance and a significant decrease in the stress index by 1.89 and 2.03 times in the active and passive periods.

Conclusions. Adding exogenous L-arginine and phenibut to the basic therapy in patients with CAD who have had COVID-19 contributes to a significant reduction in anxiety and depressive symptoms, improvement of cognitive function, and stabilization of autonomic regulation of cardiac activity, which indicates a positive neuromodulatory effect of the combination therapy.