Respiratory Medicine 109 (2015) 1138e1146
Contents lists available at ScienceDirect
Respiratory Medicine journal homepage: www.elsevier.com/locate/rmed
Prognostic value of variables derived from the six-minute walk test in patients with COPD: Results from the ECLIPSE study Vasileios Andrianopoulos a, *, Emiel F.M. Wouters a, b, Victor M. Pinto-Plata c, Lowie E.G.W. Vanfleteren a, Per S. Bakke d, Frits M.E. Franssen a, Alvar Agusti e, William MacNee f, Stephen I. Rennard g, Ruth Tal-Singer h, Ioannis Vogiatzis i, Jørgen Vestbo j, k, Bartolome R. Celli l, Martijn A. Spruit a, m a
Department of Research and Education; CIROþ, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands Department of Respiratory Medicine, Maastricht University Medical Centre (MUMCþ), Maastricht, The Netherlands c Department of Respiratory Medicine, School of Clinical Science, University of Liverpool, United Kingdom d Department of Clinical Science, University of Bergen, Bergen, Norway e Thorax Institute, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERES, Barcelona, Spain f University of Edinburgh, Medical Research Council Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, United Kingdom g Pulmonary and Critical Care Medicine, University of Nebraska Medical Center, Omaha, NE, USA h GSK Research and Development, King of Prussia, Philadelphia, PA, USA i Department of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Greece j Department of Respiratory Medicine, Odense University Hospital, Odense, Denmark k Respiratory and Allergy Research Group, Manchester Academic Health Science Center, University of Manchester, Manchester, UK l Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA m REVAL e Rehabilitation Research Center, BIOMED e Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 11 February 2015 Received in revised form 28 May 2015 Accepted 23 June 2015 Available online 25 June 2015
In addition to the six-min walk distance (6 MWD), other six-min walk test (6 MWT) derived variables, such as mean walk-speed (6MWSpeed), 6-min walk-work (6 MWW), distance-saturation product (DSP), exercise-induced oxygen desaturation (EID), and unintended stops may be useful for the prediction of mortality and hospitalization in patients with chronic obstructive pulmonary disease (COPD). We studied the association between 6 MWT-derived variables and mortality as well as hospitalization in COPD patients and compared it with the BODE index. A three-year prospective study (ECLIPSE) to evaluate the prognostic value of 6 MWT-derived variables in 2010 COPD patients. Cox's proportional-hazard regressions were performed to estimate 3-year mortality and hospitalization. During the follow-up, 193 subjects died and 622 were hospitalized. An adjusted Cox's regression model of hazard ratio [HR] for impaired 6 MWT-derived variables was significant referring to: mortality (6 MWD 334 m [2.30], 6MWSpeed 0.9 m/sec [2.15], 6 MWW 20000 m kg [2.17], DSP 290 m% [2.70], EID 88% [1.75], unintended stops [1.99]; and hospitalization (6 MWW 27000 m kg [1.23], EID 88% [1.25], BODE index 3 points [1.40]; all p 0.05). The 6 MWT-derived variables have an additional predictive value of mortality in patients with COPD. The 6 MWW, EID and the BODE index refine the prognosis of hospitalization. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Exercise testing Exercise physiology Prognostic markers Mortality Hospitalization COPD
1. Introduction
* Corresponding author. Department of Research & Education, CIROþ, Centre of Expertise for Chronic Organ Failure, Hornerheide 1, 6085 Horn, The Netherlands. E-mail address: [email protected] (V. Andrianopoulos). http://dx.doi.org/10.1016/j.rmed.2015.06.013 0954-6111/© 2015 Elsevier Ltd. All rights reserved.
The six-minute walk test (6 MWT) is a reliable, widely-used test to assess functional exercise performance in patients with chronic obstructive pulmonary disease (COPD) [1e3]. Its primary readout is the distance (meters) walked in six minutes (6 MWD). A 6 MWD
V. Andrianopoulos et al. / Respiratory Medicine 109 (2015) 1138e1146
1139
2. Material and methods Abbreviation list 2.1. Design and participants AUC
area under the receiver operating characteristic (ROC) curve BMI body mass index BODE index body-mass index, airflow obstruction, dyspnea, and exercise e score system CES-D center for epidemiologic screening test questionnaire CT computed tomography DLCO diffusion capacity DSP distance-saturation product EID exercise-induced oxygen desaturation FEV1 forced expiratory volume in 1 s FFMI fat free mass index FVC forced vital capacity HR hazard ratio LAA% the percentage of low-attenuation area (emphysema) mMRC Medical Research Council dyspnea scale SGRQ saint-george respiratory questionnaire 6 MWD six-minute walk distance 6MWSpeed six-minute walk speed 6 MWT six-minute walk test 6 MWW six-minute walk-work
Contents lists available at ScienceDirect
Respiratory Medicine journal homepage: www.elsevier.com/locate/rmed
Prognostic value of variables derived from the six-minute walk test in patients with COPD: Results from the ECLIPSE study Vasileios Andrianopoulos a, *, Emiel F.M. Wouters a, b, Victor M. Pinto-Plata c, Lowie E.G.W. Vanfleteren a, Per S. Bakke d, Frits M.E. Franssen a, Alvar Agusti e, William MacNee f, Stephen I. Rennard g, Ruth Tal-Singer h, Ioannis Vogiatzis i, Jørgen Vestbo j, k, Bartolome R. Celli l, Martijn A. Spruit a, m a
Department of Research and Education; CIROþ, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands Department of Respiratory Medicine, Maastricht University Medical Centre (MUMCþ), Maastricht, The Netherlands c Department of Respiratory Medicine, School of Clinical Science, University of Liverpool, United Kingdom d Department of Clinical Science, University of Bergen, Bergen, Norway e Thorax Institute, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERES, Barcelona, Spain f University of Edinburgh, Medical Research Council Centre for Inflammation Research, The Queen's Medical Research Institute, Edinburgh, United Kingdom g Pulmonary and Critical Care Medicine, University of Nebraska Medical Center, Omaha, NE, USA h GSK Research and Development, King of Prussia, Philadelphia, PA, USA i Department of Physical Education and Sport Sciences, National and Kapodistrian University of Athens, Greece j Department of Respiratory Medicine, Odense University Hospital, Odense, Denmark k Respiratory and Allergy Research Group, Manchester Academic Health Science Center, University of Manchester, Manchester, UK l Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA m REVAL e Rehabilitation Research Center, BIOMED e Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 11 February 2015 Received in revised form 28 May 2015 Accepted 23 June 2015 Available online 25 June 2015
In addition to the six-min walk distance (6 MWD), other six-min walk test (6 MWT) derived variables, such as mean walk-speed (6MWSpeed), 6-min walk-work (6 MWW), distance-saturation product (DSP), exercise-induced oxygen desaturation (EID), and unintended stops may be useful for the prediction of mortality and hospitalization in patients with chronic obstructive pulmonary disease (COPD). We studied the association between 6 MWT-derived variables and mortality as well as hospitalization in COPD patients and compared it with the BODE index. A three-year prospective study (ECLIPSE) to evaluate the prognostic value of 6 MWT-derived variables in 2010 COPD patients. Cox's proportional-hazard regressions were performed to estimate 3-year mortality and hospitalization. During the follow-up, 193 subjects died and 622 were hospitalized. An adjusted Cox's regression model of hazard ratio [HR] for impaired 6 MWT-derived variables was significant referring to: mortality (6 MWD 334 m [2.30], 6MWSpeed 0.9 m/sec [2.15], 6 MWW 20000 m kg [2.17], DSP 290 m% [2.70], EID 88% [1.75], unintended stops [1.99]; and hospitalization (6 MWW 27000 m kg [1.23], EID 88% [1.25], BODE index 3 points [1.40]; all p 0.05). The 6 MWT-derived variables have an additional predictive value of mortality in patients with COPD. The 6 MWW, EID and the BODE index refine the prognosis of hospitalization. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Exercise testing Exercise physiology Prognostic markers Mortality Hospitalization COPD
1. Introduction
* Corresponding author. Department of Research & Education, CIROþ, Centre of Expertise for Chronic Organ Failure, Hornerheide 1, 6085 Horn, The Netherlands. E-mail address: [email protected] (V. Andrianopoulos). http://dx.doi.org/10.1016/j.rmed.2015.06.013 0954-6111/© 2015 Elsevier Ltd. All rights reserved.
The six-minute walk test (6 MWT) is a reliable, widely-used test to assess functional exercise performance in patients with chronic obstructive pulmonary disease (COPD) [1e3]. Its primary readout is the distance (meters) walked in six minutes (6 MWD). A 6 MWD
V. Andrianopoulos et al. / Respiratory Medicine 109 (2015) 1138e1146
1139
2. Material and methods Abbreviation list 2.1. Design and participants AUC
area under the receiver operating characteristic (ROC) curve BMI body mass index BODE index body-mass index, airflow obstruction, dyspnea, and exercise e score system CES-D center for epidemiologic screening test questionnaire CT computed tomography DLCO diffusion capacity DSP distance-saturation product EID exercise-induced oxygen desaturation FEV1 forced expiratory volume in 1 s FFMI fat free mass index FVC forced vital capacity HR hazard ratio LAA% the percentage of low-attenuation area (emphysema) mMRC Medical Research Council dyspnea scale SGRQ saint-george respiratory questionnaire 6 MWD six-minute walk distance 6MWSpeed six-minute walk speed 6 MWT six-minute walk test 6 MWW six-minute walk-work
