Correlation of D-dimer level with the radiological severity indexes of pulmonary embolism on computed tomography pulmonary angiography

Abstract

Background It is known that the main role of D-dimer has been as an exclusionary test in patients with suspected venous thromboembolism. However, the D-dimer is increasingly beginning to find clinical utility as a marker in the evaluation of the extent of the embolic disease. The aim of the study was to determine whether D-dimer levels predict the radiological markers of pulmonary embolism (PE) severity using Mastora score. Methods This prospective study involved 69 patients with acute PE proved by computed tomography pulmonary angiography (CTPA). The D-dimer level was noted. A pulmonary artery obstruction index (PAOI; Mastora score) ≥21.3% indicated severe obstruction of PE. A right ventricle/left ventricle (RV/LV) ratio >0.9 indicated RV dysfunction. Results The median D-dimer level and PAOI were 765 μg/L (95% CI: 750–1 205 μg/L) and 16.77% (95% CI: 16.32%-23.06%), respectively. The D-dimer level was positively correlated with PAOI (r=0.417, P <0.000 1). PAOI ≥21.3% was associated with high D-dimer levels (median, 993 μg/L (95% CI: 856–1 841 μg/L), Z=-2.991, P=0.003). The D-dimer level was correlated with the RV/LV ratio (r=0.272, P=0.024). RV/LV ratios >0.9 were associated with high D-dimer levels (median, 880 μg/L (95% CI: 764–1 360 μg/L), Z=-2.070, P=0.038). PAOI was positively correlated with the RV/LV ratio (r =0.390, P=0.001). After three months, both the PAOI and D-dimer levels decreased (Z=-7.009, P <0.000 1; Z=-6.976, P <0.000 1, respectively). Conclusion D-dimer levels are positively correlated with PE burden and right ventricle dysfunction on CTPA, and can help monitor the therapeutic response.