Coagulation disorders and thromboembolic disease in COVID-19: review of current evidence in search of a better approach

Abstract

The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been an unprecedented global health problem, causing more than 20 million infections and more than 900,000 deaths (September 2020). The SARS-CoV-2 infection, known as COVID-19, has various clinical presentations, from asymptomatic or mild catarrhal processes to severe pneumonia that rapidly progresses to acute respiratory distress syndrome (ARDS) and multiple organ failure. In the last few months, much scientific literature has been devoted to descriptions of different aspects of the coagulation disorders and arterial and venous thrombotic complications associated with COVID-19, particularly venous thromboembolism (VTE).These studies have revealed that SARS-CoV-2 could lead to a prothrombotic state reflecting the high cumulative incidence of associated thrombotic events, particularly in patients admitted to intensive care units (ICUs). As regards the coagulopathy observed in association with SARS-CoV-2 infection, the mechanisms that activate coagulation have been hypothesized as being linked to immune responses, through the release of pro-inflammatory mediators that interact with platelets, stimulate the expression of tissue factor, induce an upregulation of plasminogen activator inhibitor-1, suppress the fibrinolytic system and lead to endothelial dysfunction, triggering thrombogenesis. D-dimer elevation has been recognized as a useful biomarker of poor prognosis, although the best cut-off point for predicting VTE in COVID-19 patients has still not been clarified. This review will try to update all the available scientific information on this important topic with enormous clinical and therapeutic implications.

The Right Ventricle in COVID-19

“…Furthermore, pathological examination of autopsy specimen of COVID-19 ARDS patients revealed the presence of microthrombotic obstruction of small pulmonary vessels, which were nine times more prevalent than in other forms of ARDS [70,71], and which displayed features of plateletrich thrombotic microangiopathy [72]. Overall, these observations indicate that COVID-19 triggers a specific phenotype of vascular involvement, characterized by a distinct pattern of coagulopathy and immune-thrombotic alterations [73]. In this respect, some authors have proposed the concept of microCLOTS (microvascular COVID-19 lung vessels obstructive thrombo-inflammatory syndrome) [74] or the concept of diffuse pulmonary intravascular coagulopathy [75] to describe these unique abnormalities of the lung circulation.…”

Follow‐up of renal transplant recipients after acute COVID‐19—A prospective cohort single‐center study

“…The most frequent pattern of coagulopathy in acute COVID‐19 patients includes increased levels of fibrinogen and D‐dimer, an increased PT and the aPTT, and a mild decrease in platelet count. 40 , 41 , 42 , 43 D‐dimer was most consistently associated with COVID‐19. 41 The phenomenon of prolonged post‐COVID‐19 procoagulant state found in our cohort may be present in the general population as well and needs to be examined.…”

“…A growing body of evidence suggests that SARS‐CoV‐2 may induce different coagulation disorders associated with inferior outcomes. The most frequent pattern of coagulopathy in acute COVID‐19 patients includes increased levels of fibrinogen and D‐dimer, an increased PT and the aPTT, and a mild decrease in platelet count 40–43 . D‐dimer was most consistently associated with COVID‐19 41 .…”

Malnutrition and venous thromboembolism are specific issues in elderly patients with coronavirus disease 2019

“…[3] On the other hand, hypoxia, inflammatory, and procoagulant state, as well as venous stasis caused by immobility, contribute to the development of venous thromboembolism (VTE) in COVID-19. [4] Besides, advanced…”