title: Heart rate recovery, exercise capacity, and mortality risk in male veterans.
abstract: BACKGROUND
  Both impaired heart rate recovery (HRR) and low fitness are associated with higher mortality risk. In addition, HRR is influenced by fitness status. The interaction between HRR, mortality, and fitness has not been clearly defined. Thus, we sought to evaluate the association between HRR and all-cause mortality and to assess the effects of fitness on this association.
  
  
  METHODS
  Treadmill exercise testing was performed in 5974 male veterans for clinical reasons at two Veterans Affairs Medical Centers (Washington, DC and Palo Alto, CA). HRR was calculated at 1 and 2 min of recovery. All-cause mortality was determined over a mean 6.2-year follow-up period.
  
  
  RESULTS
  Mortality risk was significantly and inversely associated with HRR, only at 2 min. A cut-off value of 14 beats/min at 2 min recovery was the strongest predictor of mortality for the cohort (hazard ratio = 2.4; CI 1.6-3.5). The mortality risk was overestimated when exercise capacity was not considered. When both low fitness and low HRR were present (≤6 metabolic equivalents and ≤14 beats/min), mortality risk was approximately seven-fold higher compared to the High-fit + High-HRR group (>6 metabolic equivalents and >14 beats/min).
  
  
  CONCLUSIONS
  HRR at 2 min post exercise is strongly and inversely associated with all-cause mortality. Exercise capacity affects HRR-associated mortality substantially and should be considered when applying HRR to estimate mortality.
authors: Veterans Affairs Medical Center, Georgetown University School of Medicine and George Washington University School of Medicine, 50 Irving Street NW, Washington, DC 20422, USA. peter.kokkinos@med.va.gov
authors: Peter
authors: P
authors: Kokkinos
authors: Jonathan
authors: J
authors: Myers
authors: Michael
authors: M
authors: Doumas
authors: Charles
authors: C
authors: Faselis
authors: Andreas
authors: A
authors: Pittaras
authors: Athanasios
authors: A
authors: Manolis
authors: John Peter
authors: JP
authors: Kokkinos
authors: Puneet
authors: P
authors: Narayan
authors: Vasilios
authors: V
authors: Papademetriou
authors: Ross
authors: R
authors: Fletcher
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000187:drug effects / Q000502:physiology*; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D011379:Prognosis; D012306:Risk; D016019:Survival Analysis; D014728:Veterans
chemical_list: D000319:Adrenergic beta-Antagonists