title: Acute and chronic effects of surgical thromboendarterectomy on exercise capacity and ventilatory efficiency in patients with chronic thromboembolic pulmonary hypertension.
abstract: OBJECTIVE
  To assess acute and chronic effects of surgical thromboendarterectomy on exercise capacity and ventilatory efficiency in patients with chronic thromboembolic pulmonary hypertension (CTEPH).
  
  
  METHODS
  Cardiopulmonary exercise testing was performed in 20 patients with CTEPH before thromboendarterectomy (baseline), one month after (early phase), and four months after (late phase). Peak oxygen uptake (peak VO(2)) and the ventilatory response to carbon dioxide production (VE-VCO(2) slope) were measured for assessment of exercise capacity and ventilatory efficiency. Right heart catheterisation was performed in all patients before and one month after surgery.
  
  
  RESULTS
  Baseline peak VO(2) decreased and VE-VCO(2) slope increased along with the increase in pulmonary vascular resistance in patients with CTEPH. After thromboendarterectomy, the VE-VCO(2) slope decreased greatly from baseline to the early phase (mean (SD), 50 (9) to 37 (7), p < 0.05) and reached a steady level thereafter. In contrast, a continued increase in peak VO(2) was noted from the early to the late phase (16.9 (4.1) to 21.1 (5.0) ml/kg/min, p < 0.05). The decrease in the VE-VCO(2) slope from baseline to the early phase, but not the increase in peak VO(2), correlated strongly with the decrease in pulmonary vascular resistance after surgery (r = 0.75, p < 0.01).
  
  
  CONCLUSIONS
  Thromboendarterectomy may cause an immediate improvement in ventilatory efficiency, possibly through its beneficial haemodynamic effects. In contrast, exercise capacity may continue to improve towards the late phase, reflecting peripheral adaptation to exercise.
authors.affiliation: Department of Internal Medicine, National Cardiovascular Centre, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Iwase
authors.forename: N
authors.initials: N
authors.lastname: Nagaya
authors.forename: M
authors.initials: M
authors.lastname: Ando
authors.forename: T
authors.initials: T
authors.lastname: Satoh
authors.forename: F
authors.initials: F
authors.lastname: Sakamaki
authors.forename: S
authors.initials: S
authors.lastname: Kyotani
authors.forename: H
authors.initials: H
authors.lastname: Takaki
authors.forename: Y
authors.initials: Y
authors.lastname: Goto
authors.forename: Y
authors.initials: Y
authors.lastname: Ohkita
authors.forename: M
authors.initials: M
authors.lastname: Uematsu
authors.forename: N
authors.initials: N
authors.lastname: Nakanishi
authors.forename: K
authors.initials: K
authors.lastname: Miyatake
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D002908:Chronic Disease; D004691:Endarterectomy / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D013923:Thromboembolism / Q000601:surgery*
chemical_list: D002245:Carbon Dioxide