Hypercoagulable state
COVID-19 is associated with a hypercoagulable
status.46,47 COVID-19 patients with acute respiratory
failure presented a severe hypercoagulability rather than consumptive
coagulopathy. Fibrin formation and polymerization may predispose to
thrombosis and correlate with a worse outcome.46The
incidence of venous thromboembolism could be as high as 25% in COVID-19
patients with severe pneumonia.48 In a different
cohort, the composite outcome of symptomatic acute pulmonary embolism,
deep-vein thrombosis, ischemic stroke, myocardial infarction, or
systemic arterial embolism was 31%.49The stroke rate
in COVID patients was around 1-2%.49,50The incidence
of stroke is not as high as venous thromboembolism. The evidence is
still needed to establish a causal relationship between stroke and
COVID-19. The International Society on Thrombosis and Haemosthasis
(ISTH) and American Society of Hematology (ASH) recommends prophylactic
low molecular weight heparin for venous thromboembolism in all
hospitalized COVID-19 patients in the absence of any
contraindications.51However, supporting evidence
ofprophylactic anticoagulants for stroke in AF patients with
COVID-19remains sparse. We do not know whether the anticoagulants in
COVID-19 patients with AF should be treated more aggressively even under
low CHA₂DS₂-VASc score (0 for male and 1 for female). Hypercoagulable
state in severe COVID-19 diseases was frequently observed with
concurrent multi-organ failure, which would also significantly increase
the risk of bleeding.