title: Early postoperative pulmonary vascular compliance predicts outcome after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  Despite a major reduction in pulmonary vascular resistance (PVR), patients with chronic thromboembolic pulmonary hypertension (CTEPH) do not always return to functional New York Heart Association (NYHA) class I after pulmonary endarterectomy (PEA). We hypothesized that residual abnormal compliance (Cp) after PEA is associated with incomplete functional recovery despite major improvement in PVR.
  
  
  METHODS
  The Cp of 34 consecutive patients with CTEPH was assessed before and after PEA. Cp was defined as stroke volume over pulse pressure and was divided into three groups: < 2.0 mL/mm Hg, 2.0 to 3.9 mL/mm Hg, and ≥ 4 mL/mm Hg. To establish predicted Cp after PEA, we collected an age- and gender-matched control group.
  
  
  RESULTS
  Before PEA, Cp was < 2.0 mL/mm Hg in 82% (n = 28) of the patients. After PEA, Cp improved to 2.0 to 3.9 mL/mm Hg in 11 patients and to ≥ 4.0 mL/mm Hg in 14 patients. Residual Cp < 2.0 mL/mm Hg was associated with delayed extubation and prolonged hospital stay. At 3 months' follow-up, 13 patients (93%) with postoperative Cp ≥ 4.0 mL/mm Hg returned to NYHA class I, whereas 45% with Cp of 2.0 to 3.9 mL/mm Hg and 25% with Cp < 2.0 mL/mm Hg returned to NYHA class I. In multivariate analysis, postoperative Cp ≥ 4.0 mL/mm Hg was the only predictor of functional recovery to NYHA class I. The group of patients with postoperative Cp ≥ 4.0 mL/mm Hg was also the only group to achieve hemodynamic parameters similar to those of their matched control subjects.
  
  
  CONCLUSIONS
  Postoperative Cp is an important predictor of recovery after PEA. Residual vascular stiffness after PEA can be associated with persistent functional limitation and lack of complete remodeling of the right ventricle.
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada. Electronic address: marc.deperrot@uhn.on.ca.
authors.forename: Marc
authors.initials: M
authors.lastname: de Perrot
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Karen
authors.initials: K
authors.lastname: McRae
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Yaron
authors.initials: Y
authors.lastname: Shargall
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Thenganatt
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Jakov
authors.initials: J
authors.lastname: Moric
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Suzanna
authors.initials: S
authors.lastname: Mak
authors.affiliation: Toronto Pulmonary Endarterectomy Program, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: John T
authors.initials: JT
authors.lastname: Granton
mesh_terms: D002908:Chronic Disease; D003187:Compliance; D004691:Endarterectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011379:Prognosis; D011651:Pulmonary Artery / Q000503:physiopathology* / Q000601:surgery; D011655:Pulmonary Embolism / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D014655:Vascular Resistance / Q000502:physiology*