The predictive value of Wells score combined with D-dimer in the diagnosis of acute pulmonary embolism

Abstract

Objective To evaluate the predictive value of Wells score combined with D-dimer in the diagnosis of acute pulmonary embolism. Methods A total of 540 patients with suspected pulmonary embolism admitted from 2008 to 2011 were enrolled for study. The diagnosis of pulmonary embolism (PE) was confirmed by using computed tomography pulmonary angiography (CTPA) . These patients were divided into two groups: PE group and non-PE group. Comparative analysis was carried out in demographics, underlying diseases, chief complaints, physical signs, venous thrombosis risk factors, laboratory findings and Wells scores between the two groups. Results Of 502 patients selected into this study, there were 246 in PE group and 256 in Non-PE group. The incidence rates of history of recent surgery or bed-ridden, recent fracture of pelvis or lower limb, symptoms of hemoptysis, transient disturbance of consciousness, signs of unilateral lower limb swelling, hypoxia and hypocapnia of arterial blood gas analysis, elevated levels of D-dimer, high Wells score in PE group were significantly higher than those in non-PE group (P <0.05) . And there were no statistical difference in other variables found between the two groups. The areas under the ROC curve of Wells score, D-dimer and the combination of the two were 0.775 (95% CI: 0.719-0.831) , 0.802 (95% CI: 0.751-0.853) and 0.899 (95% CI: 0.834-0.964) , respectively. And the area under the ROC curve of the combination of the two was greater than that of separated application (P <0.05) . When the cut-off value of Wells score was 5 and D-dimer was 1 724 μg/L, the weighted maximum sensitivity and specificity were reached, and these cut-off values were higher than above determined values, the reliability of the diagnosis of PE was obviously increased, and those were lower than these cut-off values, the reliability of excluding PE was also increased. Conclusions Wells score combined with D-dimer showed a higher value in predicting acute pulmonary embolismthan than their separated application. Key words: Acute pulmonary embolism; Wells Score; D-dimer; Clinical prediction