title: Pulmonary vascular and right ventricular reserve in patients with normalized resting hemodynamics after pulmonary endarterectomy.
abstract: BACKGROUND
  Patients with normalized mean pulmonary artery pressure (mPAP) after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) do not always regain normal exercise capacity. We evaluated right ventricular function, its interaction with both pulsatile and resistive afterload, and the effect of sildenafil during exercise in these patients.
  
  
  RESULTS
  Fourteen healthy controls, 15 CTEPH patients, and 7 patients with normalized resting mPAP (≤25 mm Hg) post-PEA underwent cardiopulmonary exercise testing, followed by cardiac magnetic resonance imaging with simultaneous invasive mPAP measurement during incremental supine cycling exercise. Peak oxygen consumption and peak heart rate were significantly reduced in post-PEA and CTEPH patients compared to controls. The mPAP-cardiac output slope was steeper in post-PEA patients than in controls and similar to CTEPH. Relative to controls, resting right ventricular ejection fraction was reduced in CTEPH, but not in post-PEA patients. In contrast, peak exercise right ventricular ejection fraction was reduced both in post-PEA and CTEPH patients. Exercise led to reduction of pulmonary arterial compliance in all groups. Nevertheless, resting pulmonary arterial compliance values in CTEPH and post-PEA patients were even lower than those in controls at peak exercise. In post-PEA patients, sildenafil did not affect resting hemodynamics nor right ventricular function, but decreased the mPAP/cardiac output slope and increased peak exercise right ventricular ejection fraction.
  
  
  CONCLUSIONS
  Exercise intolerance in post-PEA patients is explained by abnormal pulmonary vascular reserve and chronotropic incompetence. The mPAP/cardiac output slope and pulmonary arterial compliance are sensitive measures demonstrating abnormal resistive and pulsatile pulmonary vascular function in post-PEA patients. These abnormalities are partially attenuated with sildenafil.
authors: Department of Cardiovascular Medicine, University Hospitals Leuven, Belgium (G.C., A.L.G.) Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium (G.C., A.L.G., P.C.).
authors: Guido
authors: G
authors: Claessen
authors: Department of Cardiovascular Medicine, University Hospitals Leuven, Belgium (G.C., A.L.G.) Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy, Australia (A.L.G.) Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium (G.C., A.L.G., P.C.).
authors: Andre
authors: A
authors: La Gerche
authors: Department of Radiology, University Hospitals Leuven, Belgium (S.D.) Department of Imaging & Dynamics, KU Leuven, Leuven, Belgium (S.D.).
authors: Steven
authors: S
authors: Dymarkowski
authors: Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium (G.C., A.L.G., P.C.).
authors: Piet
authors: P
authors: Claus
authors: Department of Pneumology, University Hospitals Leuven, Belgium (M.D.) Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium (M.D.).
authors: Marion
authors: M
authors: Delcroix
authors: Hasselt University and Heart Center, Jessa Hospital, Hasselt, Belgium (H.H.).
authors: Hein
authors: H
authors: Heidbuchel
mesh_terms: D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D001642:Bicycling; D016022:Case-Control Studies; D002407:Catheterization, Swan-Ganz; D002908:Chronic Disease; D003187:Compliance; D004691:Endarterectomy; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000187:drug effects; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D058986:Phosphodiesterase 5 Inhibitors / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery*; D011655:Pulmonary Embolism / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D020127:Recovery of Function; D012307:Risk Factors; D000068677:Sildenafil Citrate / Q000627:therapeutic use; D013318:Stroke Volume; D016896:Treatment Outcome; D016278:Ventricular Function, Right / Q000187:drug effects; D055815:Young Adult
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D000068677:Sildenafil Citrate
keywords: cardiac magnetic resonance imaging; chronic thromboembolic pulmonary hypertension; exercise; pulmonary arterial compliance; pulmonary vascular resistance; right ventricle