title: Submaximal fitness and mortality risk reduction in coronary heart disease: a retrospective cohort study of community-based exercise rehabilitation.
abstract: To examine the association between submaximal cardiorespiratory fitness (sCRF) and all-cause mortality in a cardiac rehabilitation (CR) cohort.
  
  
  
  Retrospective cohort study of participants entering CR between 26 May 1993 and 16 October 2006, followed up to 1 November 2013 (median 14 years, range 1.2-19.4 years).
  
  
  
  A community-based CR exercise programme in Leeds, West Yorkshire, UK.
  
  
  
  A cohort of 534 men (76%) and 136 women with a clinical diagnosis of coronary heart disease (CHD), aged 22-82 years, attending CR were evaluated for the association between baseline sCRF and all-cause mortality. 416 participants with an exercise test following CR (median 14 weeks) were examined for changes in sCRF and all-cause mortality.
  
  
  
  All-cause mortality and change in sCRF expressed in estimated metabolic equivalents (METs).
  
  
  
  Baseline sCRF was a strong predictor of all-cause mortality; compared to the lowest sCRF group (<5 METs for women and <6 METs for men), mortality risk was 41% lower in those with moderate sCRF (HR 0.59; 95% CI 0.42 to 0.83) and 60% lower (HR 0.40; 95% CI 0.25 to 0.64) in those with higher sCRF levels (≥7 METs women and ≥8 METs for men). Although improvement in sCRF at 14 weeks was not associated with a significant mortality risk reduction (HR 0.91; 95% CI 0.79 to 1.06) for the whole cohort, in those with the lowest sCRF (and highest all-cause mortality) at baseline, each 1-MET improvement was associated with a 27% age-adjusted reduction in mortality risk (HR 0.73; 95% CI 0.57 to 0.94).
  
  
  
  Higher baseline sCRF is associated with a reduced risk of all-cause mortality over 14 years in adults with CHD. Improving fitness through exercise-based CR is associated with significant risk reduction for the least fit.
authors.affiliation: Department of Sport, Health and Exercise Science, University of Hull, Hull, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Taylor
authors.affiliation: Carnegie School of Sport, Leeds Beckett University, Leeds, UK.
authors.forename: Costas
authors.initials: C
authors.lastname: Tsakirides
authors.affiliation: Burton Croft Surgery, Leeds, UK.
authors.forename: James
authors.initials: J
authors.lastname: Moxon
authors.affiliation: Retired General Practitioner, Leeds, UK.
authors.forename: James William
authors.initials: JW
authors.lastname: Moxon
authors.affiliation: Retired Fitness Development Officer, Sports Development, Leeds Leisure Services, Leeds, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Dudfield
authors.affiliation: Division of Cardiovascular and Diabetes Research, University of Leeds, Leeds, UK.
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Witte
authors.affiliation: Department of Sport, Health and Exercise Science, University of Hull, Hull, UK.
authors.forename: Lee
authors.initials: L
authors.lastname: Ingle
authors.affiliation: Department of Sport, Health and Exercise Science, University of Hull, Hull, UK.
authors.forename: Sean
authors.initials: S
authors.lastname: Carroll
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000072599:Cardiorespiratory Fitness; D002423:Cause of Death; D003327:Coronary Disease / Q000401:mortality / Q000534:rehabilitation*; D005081:Exercise Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D040242:Risk Reduction Behavior; D055815:Young Adult
keywords: CHD; cardiac rehabilitation; cardiorespiratory fitness; submaximal exercise testing; survival