COVID-19 associated coagulopathy in critically ill patients: A hypercoagulable state demonstrated by parameters of haemostasis and clot waveform analysis

Fan, Bingwen Eugene; Ng, Jensen; Chan, Stephrene Seok Wei; Christopher, Dheepa; Tso, Allison Ching Yee; Ling, Li Min; Young, Barnaby Edward; Wong, Lester Jun Long; Sum, Christina Lai Lin; Tan, Hwee Tat; Ang, Mui Kia; Lim, Gek Hsiang; Ong, Kiat Hoe; Kuperan, Ponnudurai; Chia, Yew Woon

Patients with COVID-19 are known to be at risk of developing both venous, arterial and microvascular thrombosis, due to an excessive immuno-thrombogenic response to the SARS-CoV-2 infection. Overlapping syndromes of COVID-19 associated coagulopathy with consumptive coagulopathy and microangiopathy can be seen in critically ill patients as well. Blood was collected from 12 Intensive Care Unit (ICU) patients with severe COVID-19 who were on either mechanical ventilation or on high flow oxygen with a PaO2/FiO2 ratio of <300 mmHg. Laboratory tests were performed for parameters of haemostasis, clot waveform analysis and anti-phospholipid antibodies. CWA parameters were raised with elevated aPTT median Min1 (clot velocity) 9.3%/s (IQR 7.1–9.9%/s), elevated PT median Min1 10.3%/s (IQR 7.1–11.1%/s), elevated aPTT median Min2 (clot acceleration) 1.5%/s(2) (IQR 1.0–1.6%/s(2)), elevated PT median Min2 5.2%/s(2) (3.6–5.7%/s(2)), elevated aPTT median Max2 (clot deceleration) 1.3%/s(2) (IQR 0.8–1.4%/s(2)) elevated PT median Max2 3.8%/s(2) (IQR 2.6–4.2%/s(2)), increased aPTT median Delta change (decreased light transmission due to increased clot formation) 87.8% (IQR 70.2–91.8%) and PT median Delta change 33.0%. This together with raised median Factor VIII levels of 262.5%, hyperfibrinogenemia (median fibrinogen levels 7.5 g/L), increased median von Willebrand factor antigen levels 320% and elevated median D-dimer levels 1.7 μg/dl support the diagnosis of COVID-19 associated coagulopathy. A lupus anticoagulant was present in 50% of patients. Our laboratory findings further support the view that severe SARS-CoV-2 infection is associated with a state of hypercoagulability.