Pulmonary embolism: role of D-dimer

Background. Pulmonary embolism ( PE) is a common condition with a real impact not well known for its clinical variability and diagnostic difficulties. Several studies have demonstrated the clinical utility of D-dimer (DD), but its positive predictive value is low, forcing to perform other diagnostic techniques to confirm. Objectives. To determine the usefulness of positive DD, assess the correlation of clinical signs, and analyze the use of oral anticoagulation (OAC) to the diagnosis of PE. Methods and material. There were evaluated 58 patients admitted with clinical suspicion of PE and positive DD from June 2009 to February 2012, which were performed lung scan ventilation/perfusion (V/Q scan). We evaluated risk factors (RF), clinical features and OAC therapy at discharge. Results. Of all patients, 60% were female and 74% were >65 years. Thirty-six (62%) patients had V/Q scan positive and the following clinical features: 23 (64%) RF positive, 21 (58%) signs of deep vein thrombosis (DVT), 22 (61%) dyspnea, 6 (16%) chest pain, 11 (30%) tachycardia and 4 (11%) cough. The remaining patients (n= 22, 38%) were: 15 (68%) RF positive, 10 (45%) signs of DVT, 15 (68%) dyspnea, 2 (9%) chest pain, 5 (23%) tachycardia and 5 (23%) cough, without significant differences between the two groups. All patients with V/Q scan positive received OAC therapy at discharge and only 11 (50%) patients had negative V/Q scan, with significant differences. Conclusion. The positive DD did not predict the diagnosis of PE, demonstrating the importance of V/Q scan to confirm the diagnosis. There were no significant differences in age, sex, risk factors and clinical presentation. Outpatient treatment with ACO was significantly associated with the diagnosis by V/Q scan and not by the presence of positive DD.