title: Safety of withholding anticoagulant therapy in patients with suspected pulmonary embolism with a negative multislice computed tomography pulmonary angiography.
abstract: BACKGROUND
  To assess the safety of withholding anticoagulant therapy in patients with clinically suspected pulmonary embolism with a negative multislice computed tomography pulmonary angiography (MCTPA).
  
  
  METHODS
  Three hundred and eighty six patients who were consecutively assessed in the emergency room of our institution for suspected pulmonary embolism were eligible for our study. Patients with either a low or an intermediate clinical probability of pulmonary embolism according to the Wells score and a negative MCTPA for pulmonary embolism were enrolled. Patients with anticoagulant therapy for other medical conditions were excluded from this study. We assessed the percentage of patients in whom venous thromboembolic events or death related to this condition within three months after the negative CT.
  
  
  RESULTS
  Two hundred and forty two patients were included in our series [mean age+/-standard deviation (SD) (63.1+/-18.1)]. Only one patient (0.41% [95% confidence interval -0.4%-1.22%]) showed a non-fatal pulmonary embolism during the three-month follow-up period after an initial negative CT scan (negative predictive value, 99.58%). Eleven patients died during the follow-up period due to conditions unrelated to venous thromboembolic disease (pneumonia [n=5], lung cancer [n=2], wasting syndrome [n=1], acute myocardial infarction [n=1], leiomyosarcoma [n=1], and severe pulmonary hypertension [n=1]).
  
  
  CONCLUSIONS
  Withholding anticoagulant therapy in patients with suspected venous thromboembolic disease with a negative result on MCTPA seems to be safe in our clinical setting.
authors.affiliation: Servicio de Urgencias, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Spain. javiergalipienzogarcia@yahoo.es
authors.forename: Javier
authors.initials: J
authors.lastname: Galipienzo
authors.forename: Jaime
authors.initials: J
authors.lastname: García de Tena
authors.forename: Julio
authors.initials: J
authors.lastname: Flores
authors.forename: Concepción
authors.initials: C
authors.lastname: Alvarez
authors.forename: Soledad
authors.initials: S
authors.lastname: Alonso-Viteri
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruiz
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011652:Pulmonary Circulation; D011655:Pulmonary Embolism / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality; D014057:Tomography, X-Ray Computed; D054556:Venous Thromboembolism / Q000209:etiology
chemical_list: D000925:Anticoagulants