Preventive anticoagulation beneficial to critically ill COVID-19 patients

Prophylactic treatment with high-dose anticoagulant helps reduce thrombotic complications in critically ill COVID-19 patients without increasing the risk of haemorrhage, a study has shown.

The study included 538 patients (median age, 63 years; 72 percent male) referred to the intensive care unit (ICU) for COVID-19. The lowest PaO2/FiO2 ratio within the ICU stay was 93 mm Hg, and 44 patients (8 percent) received extracorporeal membrane oxygenation (ECMO) thrombosis.

At ICU admission, patients had high levels of fibrinogen (median, 6.9 g/l), D-dimer (median, 1.56 mg/l), and FVIII and Von Willebrand Factor antigen (median, 262 and 395 IU/dL, respectively). The corresponding activated partial thromboplastin time ratio, international normalized ratio, and platelet count were 1.10, 1.12, and 226 10⁹/L.

In total, 104 patients developed a total of 122 thrombotic complications, with an incidence of 22.7 percent. The most common complication was pulmonary embolism (52 percent). These complications occurred frequently in patients receiving continuous renal replacement therapy (44.8 percent) or those supported by ECMO (43.2 percent).

High-dose prophylactic anticoagulation was associated with a significantly lower risk of thrombotic complications (hazard ratio [HR], 0.81, 95 percent confidence interval [CI], 0.66–0.99) without increasing the incidence of bleeding events (HR, 1.11, 95 percent CI, 0.70–1.75). Risk factors for thrombotic complications were D-dimer level and PaO2/FiO2 ratio at ICU admission, ECMO, and renal replacement therapy.

Randomized controlled trials evaluating prophylaxis with higher doses of anticoagulants are warranted to confirm the present data.