Incidence of deep venous thrombosis in COVID-19 critically ill patients treated with intermediate-dose of heparin for thromboprophylaxis: The COVIDOP-DVT observational study.

Introduction: The high prevalence of deep vein thrombosis (DVT) in patients admitted to intensive care unit (ICU) for COVID-19-related acute respiratory distress syndrome (ARDS) would justify systematic screening of these patients or higher therapeutic dose of heparin for thromboprophylaxis.

Material and method: We performed a systematic echo-Doppler of the lower limb proximal veins during the first 48 h (visit 1) and from 7 to 9 days after visit 1 (visit 2) in consecutive patients admitted to the ICU of a university-affiliated tertiary hospital for severe proven COVID-19 during the second wave. All patients received intermediate-dose heparin (IDH). The primary objective was to determine DVT incidence on venous Doppler ultrasound. Secondary objectives were to determine whether the presence of DVT modifies the anticoagulation regimen, the incidence of major bleeding according to International Society on Thrombosis and Haemostasis (ISTH) criteria, and the mortality rate of patients with and without DVT.

Results: We included 48 patients (30 [62.5%] men) with a median age of 63 years [IQR, 54-70]. The prevalence of proximal deep vein thrombosis was 4.2% (2/48). In these two patients, after DVT diagnosis, anticoagulation was changed from intermediate to curative dose. Two patients (4.2%) had a major bleeding complication according to ISTH criteria. Among the 48 patients, 9 (18.8%) died before hospital discharge. No DVT or pulmonary embolism was diagnosed in these deceased patients during their hospital stay.

Conclusion: In critically ill patients with COVID-19, management with IDH results in a low incidence of DVT. Although our study is not designed to demonstrate any difference in outcome, our results do not suggest any signal of harm when using intermediate-dose heparin (IDH) COVID-19 with a frequency of major bleeding complications less than 5%.