title: Effects of age on aerobic capacity in heart failure patients under beta-blocker therapy: possible impact in clinical decision-making?
abstract: BACKGROUND
  Heart failure (HF) is associated with impaired maximal aerobic capacity as indicated by decreases in peak oxygen uptake (peak VO(2)). Considering that aging by itself has a negative effect on this variable, the evaluation of maximum capacity is often questioned because current predicted peak VO(2) is based on subjects without heart disease or b-blocker therapy. In contrast, if decline in predicted and attained peak VO(2) were age-related, proportionally, loss of aerobic function (predicted peak VO(2), %) would remain stable over time in these patients. The purpose of this investigation is to assess the effects of age on peak VO(2) in HF patients taking b-blockers.
  
  
  METHODS
  We retrospectively evaluated 483 (132 female) patients (aged 20-88 years, LVEF 31 ± 11%) with non-ischemic (n = 362), ischemic (n = 74) and Chagas-related HF (n = 47) who had been submitted to an incremental cardiopulmonary exercise testing on a motorized treadmill. Linear regression was used to develop the equation to predict peak VO(2), based on age.
  
  
  RESULTS
  Peak VO(2) decreased 0.9 mL/min/kg per age-decade, maximum HR also decreased with aging and VE/VCO(2) slope was similar among all decades. The predicted new b-blocker equation to peak VO(2 bb) was 20.934 - 0.092 × age.
  
  
  CONCLUSIONS
  Clinical interpretation of aerobic capacity impairment is influenced by aging in HF patients. This evidence must be considered when using peak VO(2) for prognostic stratification and clinical decision-making in patients with HF under b-blocker therapy.
authors: Exercise and Chronic Disease Research Laboratory, Physical Education Department, School of Sciences, São Paulo State University - UNESP, Bauru, Brazil. ciolac@fc.unesp.br.
authors: Emmanuel Gomes
authors: EG
authors: Ciolac
authors: Edimar Alcides
authors: EA
authors: Bocchi
authors: Miguel Morita
authors: MM
authors: Fernandes da Silva
authors: Aline Cristina
authors: AC
authors: Tavares
authors: Iram Soares
authors: IS
authors: Teixeira-Neto
authors: Guilherme Veiga
authors: GV
authors: Guimarães
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003661:Decision Support Techniques; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume / Q000187:drug effects; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000187:drug effects; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists