title: Post-thrombotic syndrome after catheter-directed thrombolysis for deep vein thrombosis (CaVenT): 5-year follow-up results of an open-label, randomised controlled trial.
abstract: BACKGROUND
  Post-thrombotic syndrome is a common complication after acute proximal deep vein thrombosis (DVT) and is associated with reduced quality of life and a substantial cost burden. In the 2-year results of the CaVenT study, additional catheter-directed thrombolysis reduced the risk of post-thrombotic syndrome by 14% compared with conventional therapy, but did not affect quality of life. In this study we report results at the 5-year follow-up, aiming to assess whether findings for post-thrombotic syndrome and quality of life have persisted.
  
  
  METHODS
  Between Jan 3, 2006, and Dec 22, 2009, we recruited patients aged 18-75 years with a first-time high proximal leg DVT from 20 hospitals in the Norwegian southeastern health region. With sealed envelopes, participants were randomly assigned (1:1) to standard treatment with compression stockings and anticoagulants (control group) or to standard treatment plus catheter-directed thrombolysis with alteplase within 21 days from symptom onset. Pre-specified outcomes in this analysis were post-thrombotic syndrome at 5 years as assessed with the Villalta score and scores for quality of life at 5 years with EQ-5D and the disease-specific VEINES-QOL/Sym. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00251771.
  
  
  RESULTS
  At 5 year follow-up (last date Oct 14, 2014), data were available for 176 patients (84% of the 209 patients originally randomised)--87 originally assigned to catheter-directed thrombolysis and 89 originally assigned to the control group. 37 patients (43%; 95% CI 33-53) allocated to catheter-directed thrombolysis developed post-thrombotic syndrome, compared with 63 (71%; 95% CI 61-79) allocated to the control group (p<0·0001), corresponding to an absolute risk reduction of 28% (95% CI 14-42) and a number needed to treat of 4 (95% CI 2-7). Four (5%) patients assigned to catheter-directed thrombolysis and one (1%) to standard treatment had severe post-thrombotic syndrome (Villalta score ≥ 15 or presence of an ulcer). Quality-of-life scores with either assessment scale did not differ between the treatment groups.
  
  
  CONCLUSIONS
  Additional catheter-directed thrombolysis resulted in a persistent and increased clinical benefit during follow-up for up to 5 years, supporting the use of additional catheter-directed thrombolysis in patients with extensive proximal DVT. However, allocation to this therapy did not lead to better quality of life. The optimal endovascular thrombolytic approach needs further investigation.
  
  
  BACKGROUND
  Southeastern Norway Regional Health Authority, the Research Council of Norway, University of Oslo, Oslo University Hospital.
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors: Ylva
authors: Y
authors: Haig
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors: Tone
authors: T
authors: Enden
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors: Ole
authors: O
authors: Grøtta
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Nils-Einar
authors: NE
authors: Kløw
authors: Oslo Vascular Centre, Oslo University Hospital, Oslo, Norway.
authors: Carl-Erik
authors: CE
authors: Slagsvold
authors: Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Medicine, Østfold Hospital Trust, Fredrikstad, Norway.
authors: Waleed
authors: W
authors: Ghanima
authors: Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Leiv
authors: L
authors: Sandvik
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
authors: Geir
authors: G
authors: Hafsahl
authors: Department of Haematology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Pål Andre
authors: PA
authors: Holme
authors: Department of Radiology, Østfold Hospital Trust, Fredrikstad, Norway.
authors: Lars Olaf
authors: LO
authors: Holmen
authors: Department of Internal Medicine, Oslo University Hospital, Oslo, Norway.
authors: Anne Mette
authors: AM
authors: Njaaastad
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors: Gunnar
authors: G
authors: Sandbæk
authors: Department of Haematology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Electronic address: p.m.sandset@medisin.uio.no.
authors: Per Morten
authors: PM
authors: Sandset
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D061185:Mechanical Thrombolysis / Q000009:adverse effects; D008875:Middle Aged; D009664:Norway; D054070:Postthrombotic Syndrome / Q000209:etiology*; D011788:Quality of Life; D053828:Stockings, Compression; D015912:Thrombolytic Therapy / Q000009:adverse effects; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D020246:Venous Thrombosis / Q000150:complications* / Q000628:therapy
chemical_list: D000925:Anticoagulants; D010959:Tissue Plasminogen Activator