Practically at once after the beginning of studying of a new koronavirusny infection it became clear that this pathology is associated with significant changes in the system of a hemostasis. There were numerous messages about higher tendency of patients with a koronavirusny infection to trombotichesky complications given about change of indicators of a hemostasis towards hypercoagulation. In this article we will consider coagulation markers as harbingers of heavier current of COVID-19.
Indicators of disturbance of a blood coagulation are correlated with the adverse forecast. In particular, noticeable increase in the D-dimera level and a product of degradation of fibrin is widespread among the died late patients with COVID-19.
At patients with COVID-19 increase in the D-dimera level (36–43%) is often observed and it can be also connected with heavy complications and a lethal outcome. However now interpretation of the D-dimera level during monitoring of a course of a disease is not clear as it can be not directly connected with degree weight of a course of a disease.
The same concerns also the level of troponin in blood as their range not always corresponds to acute ischemia of heart; in the absence of clinical symptoms not any increase in level of a cardiospecific troponin demands invasive assessment. However in large-scale researches the correlation of the prothrombin time (PT) with severity of a course of a disease was revealed. During the retrospective research with participation of 296 patients with COVID-19 (17 of which died), at the died late patients the D-dimera level and thrombin time were higher, and the activated partial thrombin time (APTT) is lower in comparison with the recovered patients. In a retrospective multicenter cohort research with participation of 191 patients with COVID-19 which were or are written out, or died, such indicators as PV, highly sensitive cardiospecific troponin I, a creatine kinase and D-dimer belonged to risk factors of death. Authors of Wang et al. showed that at 58% of patients with COVID-19 lengthening of PV was noted. Tang et al. investigated 207 died late patients with COVID-19 and revealed that were found in this group of patients much the increased D-dimera level and fibrin degradation products and also the extended PV at hospitalization in comparison with the recovered patients.
Activation of process of coagulation reaches the peak during the IDCS (a disseminate intravascular blood coagulation) which came before death of the most part of patients with the confirmed COVID-19. Actually, at such patients sepsis which is one of the most widespread starting factors of DVS can develop. The IDCS is result of activation of monocytes and endothelial cells for release of cytokines after disturbance, with an expression of a fabric factor and development of a factor of von Willebrand. The circulation of free thrombin which is not giving in to control by means of natural anticoagulants can cause activation of thrombocytes and stimulate a fibrinolysis. At later stages of new koronavirusny pneumonia levels of the markers connected with products of fibrin (D-dimera and a product of degradation of fibrin), it is moderate or are considerably raised in all cases of a lethal outcome that indicates the general activation of a blood coagulation and a secondary hyper fibrinolysis.
It could explain fast progressing of a disease till a lethal outcome and limited efficiency of IVL at treatment of patients with COVID-19. Protocols of use of IVL at ORDS not always bring benefit and can even cause bigger damage to lungs. But at the same time, by means of information stated above, fast and positive reaction of some patients to antitrombotichesky therapy can be explained.
Terpos et al. also showed that hypercoagulation is widespread among the hospitalized patients with COVID-19. They reported that disturbances of a blood coagulation in PV, APTV, a product of degradation of fibrin and D-dimera, along with heavy thrombocytopenia, indicate a zhizneugrozhayushchy IDCS that demands constant observation and acceptance of urgent measures. During the large-scale researches it was revealed that D-dimer and PV are connected with high severity of a disease and a lethal outcome.
Thus, if to summarize the aforesaid, it is possible to claim that influence of a new koronavirusny infection on the system of coagulation is one of important pathophysiological mechanisms which substantially defines the forecast of a disease. New researches in this area will help to decide better on therapeutic methods and to develop effective schemes of treatment.