title: Repeatability and responsiveness of exercise tests in pulmonary arterial hypertension.
abstract: Exercise tolerance in pulmonary arterial hypertension (PAH) is most commonly assessed by the 6-min walk test (6MWT). Whether endurance exercise tests are more responsive than the 6MWT remains unknown. 20 stable PAH patients (mean±sd age 53±15 years and mean pulmonary arterial pressure 44±16 mmHg) already on PAH monotherapy completed the 6MWT, the endurance shuttle walk test (ESWT) and the cycle endurance test (CET) before and after the addition of sildenafil citrate 20 mg three times daily or placebo for 28 days in a randomised double-blind crossover setting. Pre- or post-placebo tests were used to assess repeatability of each exercise test, whereas pre- or post-sildenafil citrate tests were used to assess their responsiveness. Sildenafil citrate led to placebo-corrected changes in exercise capacity of 18±25 m (p = 0.02), 58±235 s (p = 0.58) and 29±77 s (p = 0.09) for the 6MWT, the ESWT and the CET, respectively. The 6MWT was associated with a lower coefficient of variation between repeated measures (3% versus 18% versus 13%), resulting in a higher standardised response mean compared with endurance tests (0.72, 0.25 and 0.38 for the 6MWT, the ESWT and the CET, respectively). The 6MWT had the best ability to capture changes in exercise capacity when sildenafil citrate was combined with patients' baseline monotherapy, supporting its use as an outcome measure in PAH.
authors.affiliation: Centre de recherche de l'Institut Universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mainguy
authors.forename: Simon
authors.initials: S
authors.lastname: Malenfant
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Neyron
authors.forename: Sébastien
authors.initials: S
authors.lastname: Bonnet
authors.forename: François
authors.initials: F
authors.lastname: Maltais
authors.forename: Didier
authors.initials: D
authors.lastname: Saey
authors.forename: Steeve
authors.initials: S
authors.lastname: Provencher
mesh_terms: D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015444:Exercise; D005080:Exercise Test / Q000379:methods* / Q000592:standards*; D017079:Exercise Tolerance / Q000502:physiology; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000494:pharmacology; D011687:Purines / Q000494:pharmacology; D015203:Reproducibility of Results; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate