title: Exercise-induced pulmonary hypertension in scleroderma patients: a common finding but with elusive pathophysiology.
abstract: BACKGROUND
  The etiology of exercise-induced pulmonary hypertension (exPH) in systemic sclerosis (SSc) remains a complex task, as both left ventricle (LV) diastolic dysfunction and pulmonary vascular disease can contribute to its development. We determined the incidence of exPH in SSc and examined the association between pulmonary artery systolic pressure (PASP) and tissue Doppler-derived indexes of pulmonary capillary wedge pressure (PCWP).
  
  
  METHODS
  Thirty-eight patients with SSc were studied, using a cycloergometer protocol; 10 were excluded due to resting PH or absence of tricuspid regurgitation (TR); TR and mitral E-wave velocities, LV outflow tract time-velocity integral and LV septal E'-wave were measured before and in peak exercise to calculate cardiac output (CO), PCWP and pulmonary vascular resistance (PVR).
  
  
  RESULTS
  Mean age of diagnosis was 57.9 ± 8.9 years. At a mean workload of 64 ± 29 Watts, 48% of patients increased PASP ≥ 50 mmHg. PCWP, assessed by the E/e' ratio, did not change significantly during exercise (10.2 ± 3.1-10.0 ± 5.1; P = NS). Only 3 patients had elevations of the E/e' ratio ≥ 13 during exercise; 2 of them had an exercise PASP ≥ 50 mmHg, yielding a proportion of exPH due to elevated LV filling pressures of 2/11 (18%). Patients with exPH had lower DLCO and had more frequently the diffuse SSc.
  
  
  CONCLUSIONS
  The elevation of PASP during exercise in most patients of this cohort seems to be related to a reduced pulmonary vascular reserve, and not to an increase in PCWP. Further studies are warranted to determine the therapeutic, as well as prognostic implications of these findings.
authors.affiliation: Department of Cardiology, Coimbra University Hospital, Coimbra, Portugal. ruibaptista@gmail.com
authors.forename: Rui
authors.initials: R
authors.lastname: Baptista
authors.forename: Sara
authors.initials: S
authors.lastname: Serra
authors.forename: Rui
authors.initials: R
authors.lastname: Martins
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Salvador
authors.forename: Graça
authors.initials: G
authors.lastname: Castro
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomes
authors.forename: Lèlita
authors.initials: L
authors.lastname: Santos
authors.forename: Pedro
authors.initials: P
authors.lastname: Monteiro
authors.forename: Jose A Pereira
authors.initials: JA
authors.lastname: da Silva
authors.forename: Mariano
authors.initials: M
authors.lastname: Pêgo
mesh_terms: D003937:Diagnosis, Differential; D004452:Echocardiography / Q000379:methods*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012595:Scleroderma, Systemic / Q000150:complications* / Q000175:diagnosis*; D012680:Sensitivity and Specificity