title: Outpatient tinzaparin therapy in pulmonary embolism quantified with ventilation/perfusion scintigraphy.
abstract: BACKGROUND
  Out-of-hospital treatment of patients with deep-vein thrombosis (DVT) is routine in many countries regardless of frequent concomitant asymptomatic pulmonary embolism (PE) in this group. However, patients with symptoms and verified PE are still regularly treated in hospital. The objectives were to test a model for outpatient tinzaparin therapy and to evaluate its safety and efficacy in patients with symptomatic, small or medium-sized PE using quantitative ventilation/perfusion scintigraphy (qV/P SCINT) for patient selection and follow up.
  
  
  METHODS
  This prospective study included 102 patients treated with tinzaparin and warfarin for 5 days at a patient hotel. PE was quantified scintigraphically as loss of perfusion with preserved ventilation at segmental or subsegmental levels (mismatch). Points were attributed to segments of reduced ventilation (RoVent) and perfusion (RoPer). A holistic principle of interpretation was applied. Patients were excluded if they had >14 RoPer points (7 segments) or >7 RoVent points. Clinical follow-up and scintigraphy were repeated at discharge in 100 patients and after 13 months on average.
  
  
  RESULTS
  Embolism diminished by 44% after 5 days and demanding symptoms declined. There was no thromboembolic mortality in the trial. At late follow-up, PE had not recurred in patients with resolution after 5 days. In those with insufficient early response, persistent perfusion defects were usually observed.
  
  
  CONCLUSIONS
  The results indicate the safety and efficacy of outpatient treatment of PE according to our model and merit larger, multicenter, controlled studies.
authors.affiliation: Department of Internal Medicine, University Hospital Lund, Lund, Sweden.
authors.forename: Carl-Gustav
authors.initials: CG
authors.lastname: Olsson
authors.forename: Ulrika
authors.initials: U
authors.lastname: Bitzén
authors.forename: Berit
authors.initials: B
authors.lastname: Olsson
authors.forename: Pernilla
authors.initials: P
authors.lastname: Magnusson
authors.forename: Margareta S
authors.initials: MS
authors.lastname: Carlsson
authors.forename: Björn
authors.initials: B
authors.lastname: Jonson
authors.forename: Marika
authors.initials: M
authors.lastname: Bajc
mesh_terms: D000553:Ambulatory Care; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000503:physiopathology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate; D000078222:Tinzaparin; D014692:Ventilation-Perfusion Ratio
chemical_list: D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D019275:Radiopharmaceuticals; D000078222:Tinzaparin; D016284:Technetium Tc 99m Pentetate