title: Deferment of objective assessment of deep vein thrombosis and pulmonary embolism without increased risk of thrombosis: a practical approach based on the pretest clinical model, D-dimer testing, and the use of low-molecular-weight heparins.
abstract: BACKGROUND
  Treatment of patients with suspected deep vein thrombosis (DVT) or pulmonary embolism (PE) is problematic if diagnostic imaging is not immediately available. Pretest clinical probability (PCP) and D-dimer assessment can be used to identify patients for whom empirical protective anticoagulation is indicated. To evaluate whether PCP and D-dimer assessment, together with the use of low-molecular-weight heparins (LMWHs), allow objective appraisal of DVT and PE to be deferred for up to 72 hours, patients with suspected DVT and PE were prospectively examined.
  
  
  METHODS
  Patients identified with a high PCP or a moderate PCP with positive D-dimer test results received a protective full-dose treatment of LMWH; the remaining patients were discharged without anticoagulant administration. However, all patients were scheduled to undergo objective tests for DVT or PE within 72 hours. Standard antithrombotic therapy was administered when deferred diagnostic tests confirmed venous thromboembolism.
  
  
  RESULTS
  In total, 409 consecutive patients with suspected DVT and 124 with suspected PE were included in this study. A total of 23.8% (95% confidence interval [CI], 20.3%-27.3%) of patients had confirmed venous thromboembolism. At the short-term follow-up (72 hours), only a single thromboembolic event (0.2%; upper 95% CI, 0.6%) had occurred, whereas at the 3-month follow-up, 5 events (1.2%; 95% CI, 0.2%-2.1%) had occurred in patients in whom diagnosis of DVT or PE had previously been ruled out. None of the patients had major bleeding events. Ninety percent of patients were treated as outpatients.
  
  
  CONCLUSIONS
  Our study demonstrates that this approach allows the safe deferral of diagnostic procedures for DVT and PE for up to 72 hours.
authors.affiliation: Thrombosis and Hemostasis Unit, Division of Haematology, University of Palermo, Palermo, Italy. sergio.siragusa@tiscali.it
authors.forename: Sergio
authors.initials: S
authors.lastname: Siragusa
authors.forename: Raffaela
authors.initials: R
authors.lastname: Anastasio
authors.forename: Camillo
authors.initials: C
authors.lastname: Porta
authors.forename: Francesco
authors.initials: F
authors.lastname: Falaschi
authors.forename: Stefano
authors.initials: S
authors.lastname: Pirrelli
authors.forename: Piernicola
authors.initials: P
authors.lastname: Palmieri
authors.forename: Gabriella
authors.initials: G
authors.lastname: Gamba
authors.forename: Katerina
authors.initials: K
authors.lastname: Granzow
authors.forename: Alessandra
authors.initials: A
authors.lastname: Malato
authors.forename: Viviana
authors.initials: V
authors.lastname: Minardi
authors.forename: Paola
authors.initials: P
authors.lastname: Tatoni
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Bressan
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Mariani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D020246:Venous Thrombosis / Q000175:diagnosis*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D006495:Heparin, Low-Molecular-Weight; C036309:fibrin fragment D