The analysis of risk factors of pulmonary embolism in patients with negative D-dimer / 中华急诊医学杂志

ABSTRACT

Objective To analyze the risk factors of pulmonary embolism in patients with negative Ddimer in serum in order to determine the need of pulmonary computed tomography angiograph (CTA) to confirm the final diagnosis in those patients for avoidance of misdiagnosis.Methods A retrospective analysis of 106 patients suspected to suffer from pulmonary embolism (PE) with serum negative D-dimer checked with pulmonary CTA was carried out.According to the results of CTA, the patients were divided into two groups, namely PE group (n =41) and non-PE group (n =65).The difference in clinic presentation, the time elapsed from onset to visit, N-terminal pro-brain natriuretic peptide (NT-proBNP), high risk factors (such as immobilization for 3 weeks, leg swelling and pain to palpation, history of deep vein thrombosis, malignancy) and Wells score (≥ 4 points indicates probability of PE).And logistic regression analysis was made to investigate the risk factors in PE with negative D-dimer.Results The analysis study showed that 38.6％ of total patients suspected to suffer from PE with serum negative D-dimer were checked by CTA to confirm the presence of PE.One important characteristics of the D-dimer negative PE patients was the longer time consumed from onset to visit [(9.51 ±2.01) d vs.(4.01 ±1.92) d, P＜ 0.05], and majority of the CTA positive patients suspected to suffer from PE with negative D-dimer had high risks of PE (P ＜0.01).Compared with the non-PE group, the Wells score ≥4 points and the level of serum NT-proBNP significantly increased in the PE group (P ＜ 0.01).Logistic regression analysis revealed that dyspnea, high NT-proBNP level and Wells sore ≥ 4 points were risk factors for D-dimer negative PE.Conclusion Delayed treatment was the main cause of misdiagnosis of D-dimer negative PE.Dyspnea, high NT-proBNP level and Wells sore ≥4 points were risk factors for suspected PE patients with negative D-dimer, and these patients should be confirmed by pulmonary CTA.On the contrary, PE could be excluded if patients with D-dimer negative had no these risk factors.