title: Peak oxygen uptake in relation to total heart volume discriminates heart failure patients from healthy volunteers and athletes.
abstract: BACKGROUND
  An early sign of heart failure (HF) is a decreased cardiac reserve or inability to adequately increase cardiac output during exercise. Under normal circumstances maximal cardiac output is closely related to peak oxygen uptake (VO2peak) which has previously been shown to be closely related to total heart volume (THV). Thus, the aim of this study was to derive a VO2peak/THV ratio and to test the hypothesis that this ratio can be used to distinguish patients with HF from healthy volunteers and endurance athletes. Thirty-one patients with HF of different etiologies were retrospectively included and 131 control subjects (60 healthy volunteers and 71 athletes) were prospectively enrolled. Peak oxygen uptake was determined by maximal exercise test and THV was determined by cardiovascular magnetic resonance. The VO2peak/THV ratio was then derived and tested.
  
  
  RESULTS
  Peak oxygen uptake was strongly correlated to THV (r2 = 0.74, p < 0.001) in the control subjects, but not for the patients (r2 = 0.0002, p = 0.95). The VO2peak/THV ratio differed significantly between control subjects and patients, even in patients with normal ejection fraction and after normalizing for hemoglobin levels (p < 0.001). In a multivariate analysis the VO2peak/THV ratio was the only independent predictor of presence of HF (p < 0.001).
  
  
  CONCLUSIONS
  The VO2peak/THV ratio can be used to distinguish patients with clinically diagnosed HF from healthy volunteers and athletes, even in patients with preserved systolic left ventricular function and after normalizing for hemoglobin levels.
authors.affiliation: Dept of Clinical Physiology, Lund University and Skåne University Hospital, Lund, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Engblom
authors.forename: Katarina
authors.initials: K
authors.lastname: Steding
authors.forename: Marcus
authors.initials: M
authors.lastname: Carlsson
authors.forename: Henrik
authors.initials: H
authors.lastname: Mosén
authors.forename: Bo
authors.initials: B
authors.lastname: Hedén
authors.forename: Torsten
authors.initials: T
authors.lastname: Buhre
authors.forename: Björn
authors.initials: B
authors.lastname: Ekmehag
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D056352:Athletes; D001835:Body Weight; D002306:Cardiac Volume; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D010101:Oxygen Consumption; D010807:Physical Endurance; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D013318:Stroke Volume; D013548:Sweden; D013599:Systole; D016277:Ventricular Function, Left; D055815:Young Adult
chemical_list: D006454:Hemoglobins