Combined Use of Wells Scores and D-dimer Levels for the Diagnosis of Deep Vein Thrombosis and Pulmonary Embolism in COVID-19: A Retrospective Cohort Study

Abstract

Introduction Deep vein thrombosis (DVT) and pulmonary embolism (PE) are key complications of coronavirus disease 2019 (COVID-19). The study's primary outcome was assessing the utility of Wells DVT, Wells PE scores, and D-dimers in diagnosing DVT and PE. Secondary outcomes were the risk factors for the development of PE and DVT in COVID-19 patients. Materials and methods We compared COVID-19 patients with a positive and negative lower extremity (LE) duplex. A similar approach was made for patients who underwent imaging for PE. Results The prevalence of PE was 23.8% (26 out of 109 patients), and the prevalence of DVT was 33% (35 out of 106). A D-dimer of 500 ng/mL had a sensitivity of 95.6% and 93.7% for the diagnosis of PE and DVT, respectively. A Wells DVT score of 3 points had a specificity of 92.9% and sensitivity of 8.8% for DVT diagnosis in COVID-19. A Wells PE score of 4 had a specificity of 100% and a sensitivity of 20% for the diagnosis of PE. The combined approach of using a Wells DVT score of 3 in suspected DVT and a Wells PE score of 4 in suspected PE and D-dimers of 500 ng/ml has a sensitivity of 94.2% and 96.1%, respectively. In the suspected DVT group, male gender (OR 3.88, 95% CI 1.55-9.7, P=0.004), lower body mass index (BMI) (OR 0.92, 95% CI 0.86-0.99, P=0.037), antiplatelet use (OR 0.19, 95% CI 0.04-0.88, P=0.035), systolic blood pressure ≤100 mmhg (OR 4.96, 95% CI 1.37-17.86, P=0.014), absolute lymphocytes ≤1 (OR 2.57, 95% CI 1.07-6.12, P=0.033), D-dimer ≥500 ng/ml (OR 6.42, 95% CI 1.40-29.38, P=0.016), blood urea nitrogen (BUN) ≥20 mg/dl (OR 2.33, 95% CI 1.00-5.41, P=0.048), and intubation (OR 3.32, 95% CI 1.26-8.78, P=0.015) were found to be statistically significant for DVT. In the suspected PE group, history of cancer (OR 10.69, 95% CI 1.06-107.74, P=0.044), total WBC count (OR 1.07, 95% CI 0.95-1.21, P=0.032), platelets ≥ 400,000 (OR 5.13, 95% CI 1.79-14.68, P=0.002), D-dimer levels ≥ 500 ng/ml (OR 25.47, 95% CI 3.27-197.97, P=0.002), Wells PE score (OR 2.46, 95% CI 1.50-4.06, P<0.001), pulmonary embolism rule-out criteria (PERC) score (OR 1.79, 95% CI 1.05-3.05, P=0.054), and Sequential Organ Failure Assessment (SOFA) score (OR 1.91, 95% CI 1.16-3.12, P=0.002) were statistically significant. Conclusions The combined approach of using a Wells DVT score of 3 in suspected DVT and Wells PE score of 4 in suspected PE and D-dimers of 500 ng/ml may be used to diagnose PE and DVT in COVID-19. Venous thromboembolism (VTE) occurrence in COVID-19 is associated with non-traditional risk factors such as intubation and higher severity of systemic inflammation, and these patients may benefit from more aggressive testing for VTE.

Keywords: covid-19; d-dimers; deep vein thrombosis; pulmonary embolism; wells dvt score; wells pe score.

Figure 1. ROC analysis for Wells scores and D-dimers

ROC: receiver operating characteristic

Figure 2. Distribution of D-dimer and Wells DVT scores in COVID-19 DVT

+ve represents DVT positive. -ve represents DVT negative.

Figure 3. Distribution of Wells PE scores and D-dimers in COVID-19 PE

+ve represents DVT positive. -ve represents DVT negative. PE: pulmonary embolism; DVT: deep vein thrombosis