title: Longitudinal follow-up of six-minute walk distance after pulmonary endarterectomy.
abstract: BACKGROUND
  The 6-minute walk test is a useful tool to assess functional outcome after pulmonary endarterectomy (PEA) in chronic thromboembolic pulmonary hypertension. However, little is known about the longitudinal dynamics in functional improvement. We performed a longitudinal follow-up of 6-minute walk distance, New York Heart Association functional class, and echocardiography after PEA.
  
  
  METHODS
  We studied 71 patients with chronic thromboembolic pulmonary hypertension who underwent PEA. A 6-minute walk test and echocardiography were performed before PEA, at 3 months after, and at annual follow-up. At the time of this report, 52 patients had returned for 2-year follow-up, 32 for 3-year follow-up, 23 for 4-year follow-up, and 11 for 5-year follow-up.
  
  
  RESULTS
  Preoperatively, the 6-minute walk distance (6-MWD) correlated with hemodynamic severity of disease (mean pulmonary artery pressure: r = -0.55, p < 0.001); total pulmonary resistance: r = -0.59, p < 0.001) After PEA, 6-MWD increased from 440 ± 109 to 524 ± 83 meters at 1 year (n = 71, p < 0.001). Further improvement was observed from 523 ± 87 meters at 1 year to 536 ± 91 meters at 2 years (n = 52, p < 0.012). After 2 years, no further improvement was observed. At 1 year, the change in 6-MWD from baseline correlated significantly with the change observed in pulmonary hemodynamics. Changes in 6-MWD and hemodynamics were more pronounced in patients with residual pulmonary hypertension after PEA, despite the worse absolute outcome.
  
  
  CONCLUSIONS
  In patients with chronic thromboembolic pulmonary hypertension, 6-MWD showed a gradual improvement up to 2 years after PEA. Patients with residual pulmonary hypertension benefited most from treatment, despite the worse absolute outcome.
authors: Department of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. m.n.vanderplas@amc.uva.nl
authors: Mart N
authors: MN
authors: van der Plas
authors: Sulaiman
authors: S
authors: Surie
authors: Herre J
authors: HJ
authors: Reesink
authors: Reindert P
authors: RP
authors: van Steenwijk
authors: Jaap J
authors: JJ
authors: Kloek
authors: Paul
authors: P
authors: Bresser
mesh_terms: D004691:Endarterectomy; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000150:complications / Q000601:surgery*; D013997:Time Factors; D016138:Walking