title: Effect of pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension on stroke volume response to exercise.
abstract: In pulmonary hypertension, exercise is limited by an impaired right ventricular (RV) stroke volume response. We hypothesized that improvement in exercise capacity after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is paralleled by an improved RV stroke volume response. We studied the extent of PEA-induced restoration of RV stroke volume index (SVI) response to exercise using cardiac magnetic resonance imaging (cMRI). Patients with CTEPH (n = 18) and 7 healthy volunteers were included. Cardiopulmonary exercise testing and cMRI were performed before and 1 year after PEA. For cMRI studies, pre- and post-operatively, all patients exercised at 40% of their preoperative cardiopulmonary exercise testing-assessed maximal workload. Post-PEA patients (n = 13) also exercised at 40% of their postoperative maximal workload. Control subjects exercised at 40% of their predicted maximal workload. Preoperatively, SVI (n = 18) decreased during exercise from 35.9 ± 7.4 to 33.0 ± 9.0 ml·m(2) (p = 0.023); in the control subjects, SVI increased (46.6 ± 7.6 vs 57.9 ± 11.8 ml·m(-2), p = 0.001). After PEA, the SVI response (ΔSVI) improved from -2.8 ± 4.6 to 4.0 ± 4.6 ml·m(2) (p <0.001; n = 17). On exercise at 40% of the postoperative maximal workload, SVI did not increase further and was still significantly lower compared with controls. Moreover, 4 patients retained a negative SVI response, despite (near) normalization of their pulmonary hemodynamics. The improvement in SVI response was accompanied by an increased exercise tolerance and restoration of RV remodeling. In conclusion, in CTEPH, exercise is limited by an impaired stroke volume response. PEA induces a restoration of SVI response to exercise that appears, however, incomplete and not evident in all patients.
authors.affiliation: Department of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Electronic address: s.surie@umcg.nl.
authors.forename: Sulaiman
authors.initials: S
authors.lastname: Surie
authors.affiliation: Department of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Respiratory Medicine, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Mart N
authors.initials: MN
authors.lastname: van der Plas
authors.affiliation: Department of Physics and Medical Technology, Institute for Cardiovascular Research, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
authors.forename: J Tim
authors.initials: JT
authors.lastname: Marcus
authors.affiliation: Department of Pulmonary Medicine, Institute for Cardiovascular Research, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
authors.forename: Taco
authors.initials: T
authors.lastname: Kind
authors.affiliation: Department of Cardiothoracic Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jaap J
authors.initials: JJ
authors.lastname: Kloek
authors.affiliation: Department of Pulmonary Medicine, Institute for Cardiovascular Research, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
authors.forename: Anton
authors.initials: A
authors.lastname: Vonk-Noordegraaf
authors.affiliation: Department of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Respiratory Medicine, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands; Department of Cardiothoracic Surgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Bresser
mesh_terms: D000792:Angiography; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D002908:Chronic Disease; D004691:Endarterectomy / Q000379:methods*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006976:Hypertension, Pulmonary / Q000503:physiopathology* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011655:Pulmonary Embolism / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology