title: Exercise capacity and peak oxygen consumption in asymptomatic patients with chronic aortic regurgitation.
abstract: BACKGROUND
  In patients with chronic, hemodynamically significant aortic regurgitation (AR), a long period of left ventricular remodeling usually occurs prior to the development of symptoms or left ventricular dysfunction. The value of cardiopulmonary exercise testing in patients with asymptomatic AR is not established.
  
  
  METHODS
  Sixty-six asymptomatic patients aged 44±14 years with hemodynamically significant, chronic AR and no indication for aortic valve replacement were evaluated by echocardiography, cardiac magnetic resonance imaging and exercise testing with measurement of peak oxygen consumption.
  
  
  RESULTS
  The average left ventricular end diastolic volume was 244±62ml and the aortic regurgitant fraction 34±13%. At an average of 35.8±8.9ml/kg/min, peak oxygen consumption was well preserved. As in healthy individuals, a high peak oxygen consumption was associated with a relatively large LV end diastolic volume (r=0.51; p<0.001) and a low resting heart rate (r=-0.37; p=0.002). The aortic regurgitant fraction was not predictive of maximum oxygen consumption. Higher levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independently associated with poorer exercise capacity and oxygen uptake (adjusted β -0.35; p=0.003).
  
  
  CONCLUSIONS
  Our results suggest that in asymptomatic patients with moderate to severe AR and moderately dilated left ventricles, remodeling is primarily adaptive. An increased level of NT-proBNP is associated with a reduced capacity for work and reduced oxygen consumption, possibly heralding the onset of adverse remodeling.
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway. Electronic address: kaspar.broch@ous-hf.no.
authors: Kaspar
authors: K
authors: Broch
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Stig
authors: S
authors: Urheim
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Richard
authors: R
authors: Massey
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Wenche
authors: W
authors: Stueflotten
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Kristian
authors: K
authors: Fosså
authors: Department of Radiology and Nuclear Medicine, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Einar
authors: E
authors: Hopp
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Postboks 4950 Nydalen, 0424 Oslo, Norway.
authors: Svend
authors: S
authors: Aakhus
authors: Department of Cardiology, Oslo University Hospital, Rikshospitalet and K. G. Jebsen Cardiac Research Centre and Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Norway.
authors: Lars
authors: L
authors: Gullestad
mesh_terms: D000293:Adolescent; D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*; D058070:Asymptomatic Diseases; D002908:Chronic Disease; D003692:Delayed-Action Preparations; D004452:Echocardiography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D020257:Ventricular Remodeling; D055815:Young Adult
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D003692:Delayed-Action Preparations; D008790:Metoprolol
keywords: Aortic regurgitation; Cardiopulmonary exercise test; Natriuretic peptides; Remodeling