title: Determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis undergoing lung transplant evaluation.
abstract: Little is known about the physiologic determinants of 6-minute walk distance in idiopathic pulmonary fibrosis. We investigated the demographic, pulmonary function, echocardiographic, and hemodynamic determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis evaluated for lung transplantation. We performed a cross-sectional analysis of 130 patients with idiopathic pulmonary fibrosis who completed a lung transplantation evaluation at the Hospital of the University of Pennsylvania between 2005 and 2010. Multivariable linear regression analysis was used to generate an explanatory model for 6-minute walk distance. After adjustment for age, sex, race, height, and weight, the presence of right ventricular dilation was associated with a decrease of 50.9 m (95% confidence interval [CI], 8.4-93.3) in 6-minute walk distance ([Formula: see text]). For each 200-mL reduction in forced vital capacity, the walk distance decreased by 15.0 m (95% CI, 9.0-21.1; [Formula: see text]). For every increase of 1 Wood unit in pulmonary vascular resistance, the walk distance decreased by 17.3 m (95% CI, 5.1-29.5; [Formula: see text]). Six-minute walk distance in idiopathic pulmonary fibrosis depends in part on circulatory impairment and the degree of restrictive lung disease. Future trials that target right ventricular morphology, pulmonary vascular resistance, and forced vital capacity may potentially improve exercise capacity in patients with idiopathic pulmonary fibrosis.
authors.affiliation: Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Porteous
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Belinda N
authors.initials: BN
authors.lastname: Rivera-Lebron
authors.affiliation: Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Maryl
authors.initials: M
authors.lastname: Kreider
authors.affiliation: Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: James
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA; Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Kawut
keywords: exercise capacity; interstitial lung disease; right ventricular dilation