title: Prognostic Significance and Determinants of the 6-Min Walk Test in Patients With Heart Failure and Preserved Ejection Fraction.
abstract: OBJECTIVE
  This study sought to define the prognostic significance and clinical determinants of the 6-min walk distance (6-MWD) in affected patients.
  
  
  BACKGROUND
  Symptoms of exertional fatigue and dyspnea, as well as a reduced exercise tolerance, are cardinal features of pulmonary hypertension associated with heart failure and preserved ejection fraction (PH-HFpEF). Mechanisms limiting exercise capacity in this specific entity remain incompletely understood.
  
  
  METHODS
  Consecutive patients with PH-HFpEF, as confirmed by right heart catheter, were enrolled in our prospective registry. Hospitalization for HF and/or death for cardiac reasons were defined as primary outcome. Multiple regression models were constructed to establish determinants of the 6-MWD. For quantification of left ventricular (LV) extracellular matrix (ECM), myocardial biopsies were taken from 18 patients.
  
  
  RESULTS
  Between December 2010 and July 2013, 142 PH-HFpEF patients were included in the study. After a mean follow-up of 14.0 ± 10.0 months, 43 patients (30.3%) reached the combined endpoint. The 6-MWD was found to be an independent predictor of outcome and was influenced by a variety of clinical, echocardiographic, hemodynamic, laboratory, and pulmonary parameters. There was a significant inverse correlation between the 6-MWD and the extent of ECM in the LV myocardium.
  
  
  CONCLUSIONS
  Impaired exercise capacity in PH-HFpEF patients is explained by cardiac and noncardiac factors. The 6-MWD predicts outcome and may be a useful endpoint in clinical trials.
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Caroline
authors.initials: C
authors.lastname: Zotter-Tufaro
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Mascherbauer
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Duca
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Koell
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Aschauer
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Kammerlander
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Adelheid
authors.initials: A
authors.lastname: Panzenboeck
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Roela
authors.initials: R
authors.lastname: Sadushi-Kolici
authors.affiliation: Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Bangert
authors.affiliation: Department of Dermatology, Medical University of Vienna, Vienna, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Laimer
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors.forename: Robin
authors.initials: R
authors.lastname: Ristl
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Irene M
authors.initials: IM
authors.lastname: Lang
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria. Electronic address: diana.bonderman@meduniwien.ac.at.
authors.forename: Diana
authors.initials: D
authors.lastname: Bonderman
mesh_terms: D000368:Aged; D006328:Cardiac Catheterization; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D016138:Walking / Q000502:physiology
keywords: cardiac catheterization; exercise test; extracellular matrix; pulmonary circulation