Diagnostic Value of D-dimer in Detecting Pulmonary Embolism in Patients with Acute COPD Exacerbation

BACKGROUND: Signs and symptoms of chronic obstructive pulmonary disease (COPD) exacerbation may overlap with pulmonary embolism. Patients with acute COPD exacerbations have higher level of D-dimer which may D-dimer lead to false detection of pulmonary thromboembolism (PTE). In this study diagnostic value of D-dimer for diagnosis of pulmonary embolism during acute exacerbation in patients with COPD was investigated. MATERIALS AND METHODS: This study was performed on 112 patients with acute COPD exacerbations. In all patients, Wells criteria and D-dimer serum levels were evaluated. Then, all cases were subjected to CT angiography (CTA) and ultrasonography. The diagnostic value of serum D-dimer level and Wells criteria and also their combination for PTE was compared to the gold standard method. RESULTS: Of 112 patients, 17%, diagnosed with PTE using CTA. The D-dimer cut-off value in COPD patients was higher than 990 μg/L, which was higher than 3 for the Wells score while D-dimer alone showed no good diagnostic value for PTE diagnosis, but Wells score was acceptable (P-value = 0.019). Moreover, the combination of cut-off values, Wells score, and D-dimer level, as a new criterion, with a sensitivity and specificity rate of 47.37% and 88.17% respectively, had an acceptable diagnostic value in PTE diagnosis (AUC=0.678, P value=0.004). CONCLUSION: It is suggested that D-dimer concentration alone could not make a good PTE diagnosis, but the simultaneous combination of this test with the Wells criterion can detect the PTE risk with better confidence. To obtain more accurate findings and to get the best criterion, further studies are needed in this field.