Incidence of deep venous thrombosis in patients with severe acute respiratory syndrome coronavirus disease 2019 and elevated plasma levels of the D-dimer

Background There is an increased risk of developing venous thromboembolism in patients with severe acute respiratory syndrome coronavirus disease (SARS COVID-19). As the D-dimer could be elevated in deep venous thrombosis (DVT), we aimed to investigate the incidence of DVT in patients with SARS COVID-19 and elevated plasma levels of the D-dimer. Patients and methods A prospective observational study was carried out to screen all patients with a confirmed diagnosis of SARS COVID-19 with plasma D-dimer levels above 1000 ng/ml for the presence of DVT without related symptoms using complete compression Doppler ultrasound. Results A total of 52 patients were included in the study. Among them, 34 (67.3%) were males. All patients received standardized thromboprophylaxis treatment. The screening results of complete compression Doppler ultrasound revealed DVT in eight (15.4%) patients. Among these patients, the DVT was proximal in one (1.9%) patient and bilateral distal in two (3.8%) patients. The D-dimer level was significantly higher in patients with DVT than in patients without DVT (4531 vs. 2048 ng/ml, odds ratio 9.4, 95% confidence interval 1.2–70.3). The diagnostic ability of the D-dimer was satisfactory, with an receiver operating characteristic curve of 0.71 (95% confidence interval 0.62–0.83). Conclusion The incidence of DVT without symptoms in patients with SARS COVID-19 and elevated plasma level of D-dimer was 15.4%, with a significant difference between patients with and without DVT in terms of the D-dimer. Therefore, the D-dimer is important for the diagnosis of DVT in patients with SARS COVID-19.