Diagnostic Value Of Clinical Score, Plasma D-dimer Testing For Acute Pulmonary Embolism

Objectives:To evaluate the value of clinical score, plasma D-dimer level, as well as their combination, in diagnosis for suspected acute pulmonary embolism. To explore a simple management strategy for patients with suspected acute pulmonary embolism.Methods:Clinical data of 243 patients suspected APE diagnosed in our hospital from January 1,2005 to May 31,2010 was analyzed retrospectively. Pulmonary embolism should be suspected in all patients who present with new or worsening dyspnea, chest pain, or sustained hypotension without an alternative obvious cause less than 14 days(obvious heart and chest disease was excluded by medical history, physical examination, chest radiograph (CR),electrocardiogram (ECG),ultrasonic cardiography (UCG), myocardium enzymology). The Wells score system and The Revised Geneva score system were used to assess the clinical probability of APE to all patients who were recruited in our study,and all of them were performed a D-dimer assay and CTPA. The diagnosis "gold standard" was CTPA. The diagnosis value was evaluated by the ROC curve and the parameter of diagnostic test.Results:102 APE patients were confirmed, high-risk group 18 patients, intermediate-risk group 32 patients, low-risk group 52 patients.There were 89 patients(87.3%) presented in dyspnea,31patients (30.4%) presented in chest pain,62patients(60.8%) presented in palpitation,15 patients(14.7%) presented in feeling of impending death, 5 patients(4.9%) presented in hemoptysis,15 patients(14.7%) presented in Syncope. The positive predictive values of Wells and Revised Geneva score in high clinical probability were 90.2%,100% respectively. The negative predictive values in low clinical probability were 84.2%,88.1% respectively, while combined with a normal D-dimer the negative predictive values in low clinical probability were elevated to 95.1%,97.3% respectively. ROC analysis showed that the area under curve(AUC)of Wells score, Revised Geneva score, D-dimer was 0.817(SE:0.028,95%CI:0.763～0.864),0.850(SE:0.025,95%CI:0.799～0.893),0.773(SE:0.031,95%CI:0.711～0.835) respectively. The statistical significance was observed only between the revised Geneva score and the D-dimer testing(Z=2.369, P=0.0178).Conclusion:The Wells score and The Revised Geneva score have similar accuracy in predicting the probability of APE. Clinical score (The Wells score or The Revised Geneva score) in combination with D-dimer is a safe and utility management strategy for patients with suspected acute pulmonary embolism. Clinical probability assessment is the logical first step, D-dimer is the first-line test in patients with a low or unlikely clinical probability, MDCT is the second-line test in patients with an elevated D-dimer level and the first-line test in patients with an intermediate, high or likely clinical probability.