Influence of platelet hemostasis on QT interval dispersion in patients with chronic ischemic heart disease and COVID-19

Coronavirus disease COVID-19 impairs platelet hemostasis, heart rate variability (HRV) and QT interval dispersion, increasing the risk of thromboembolic complications and cardiovascular mortality. Our study aimed to investigate the impact of COVID-19 on the interdependence of changes in platelet hemostasis and QT interval dispersion in patients with ischemic heart disease (IHD). We analyzed laboratory and instrumental results of 102 patients divided into 3 groups: group 1 consisted of IHD without COVID-19 patients (n = 32); group 2 − IHD in combination with COVID-19 (n = 35); group 3 − COVID-19 without IHD (n = 35). The control group included 30 conditionally healthy volunteers. Changes in platelet hemostasis were studied with laser aggregometry using the Born turbidimetric method and with light transmission fluctuation analysis using an assessment of spontaneous and induced aggregation: adenosine diphosphate (ADP), arachidonic acid, epinephrine, collagen, and ristomycin. The results of 24-hour Holter ECG monitoring were used to determine the QT interval dispersion. In patients of group 2, there was an increase in the degree, rate and time of spontaneous platelet aggregation, as well as a decrease in the degree, rate and time of platelet aggregation induced by epinephrine, a decrease in the rate of aggregation induced by arachidonic acid and ADP. The degree of aggregation was higher when using collagen and ristomycin. The QT interval duration and variability increased in all patients, especially in group 2. The time of spontaneous aggregation, as well as ADP- and collagen-induced aggregation, was directly correlated with the QT mode and mean. The standard deviation and coefficient of variation of QT were inversely related to the time of spontaneous aggregation, collagen- and ristomycin-induced and arachidonic acid-induced aggregation. The rate of aggregation did not affect the QT interval variability. Thus, patients with IHD and concomitant COVID-19 along with platelet hemostasis dysfunction exhibited signs of autonomic dysregulation and increased QT interval duration and variability. Careful consideration of platelet hemostasis characteristics and QT interval variability is recommended in the management of these patients.