Predictive value of D-Dimer levels for Pulmonary Thromboembolism at initial COVID-19 Diagnosis: Experience from a Tertiary Care Hospital

Abstract

Background: Coronavirus disease 2019 (COVID-19) carries a higher risk of thromboembolic complications, especially pulmonary thromboembolism (PTE). Identifying PTE early is important but can be hard because of similar respiratory symptoms. D-dimer, a common biomarker, may help predict thrombotic risk. Still, experts do not know the best cutoff level for D-dimer in COVID-19 patients. Objective: This study aims to find out how often pulmonary thromboembolism (PTE) occurs at the time of COVID-19 diagnosis and to see how D-dimer levels relate to patients with COVID-19. Methodology: This retrospective study included 240 confirmed COVID-19 patients who had CT pulmonary angiography (CTPA) when they were admitted to the hospital for suspected pulmonary thromboembolism (PTE). We collected and analyzed admission D-dimer levels and clinical data. Patients were divided into groups based on whether they had PTE or not. We used receiver operating characteristic (ROC) analysis to find the best D-dimer cutoff value for predicting PTE. Results: PTE was found in 32 out of 240 patients (13.3%) using CTPA. Median D-dimer levels were significantly higher in patients with PTE compared to those without (1680 ng/mL vs 980 ng/mL, p<0.001). ROC analysis showed an area under the curve (AUC) of 0.667, and a D-dimer cutoff of 1000 ng/mL gave the best diagnostic performance. Age and male gender also emerged as independent predictors of PTE. Conclusion: D-dimer is a helpful predictor of pulmonary thromboembolism in COVID-19 patients at the time of hospital admission. A cutoff of 1000 ng/mL provides a practical balance between sensitivity and specificity. Age and being male further raise the risk of PTE. Early assessment with D-dimer could help with timely diagnosis and management.