Fitness Does Not Retire: Cardiorespiratory Fitness and Risk of Major Adverse Cardiovascular Events in Older Adults.

AIMS: To evaluate the association between cardiorespiratory fitness (CRF), directly measured as peak oxygen uptake (VO2peak), and the risk of major adverse cardiovascular events (MACE) in older Norwegian adults. METHODS: A total of 1547 individuals aged 70-77 years (784 women) from the Generation 100 Study, examined in 2012 and 2013, were studied. We defined MACE as the first occurrence of acute myocardial infarction, stroke, heart failure, or cardiovascular death. Sex- and cohort-specific VO2peak categories (20% least fit, 80% fit) were established based on baseline VO2peak and changes over one year. Associations between baseline VO2peak, one-year fitness trajectories, and MACE were assessed using competing risk regression to estimate subdistribution hazard ratios (sHRs) and 95% confidence intervals (CIs). RESULTS: During follow-up (median, 10.0 years; IQR, 9.2-10.0 years), 294 individuals experienced MACE (185 men, 109 women). Higher baseline VO2peak was inversely associated with MACE in both sexes. Compared with unfit participants, those with a VO2peak ≥26.0 mL/kg/min in men and ≥22.2 mL/kg/min in women had lower risk of MACE (men: sHR, 0.76; 95% CI, 0.54-0.99; women: sHR, 0.59; 95% CI, 0.39-0.90). Compared with those who remained unfit over one year, men and women who remained fit had 36% (sHR, 0.64; 95% CI, 0.42-0.99) and 42% lower risk (sHR, 0.58; 95% CI, 0.33-0.99), respectively. CONCLUSION: In older Norwegian adults, higher CRF was inversely associated with long-term risk of MACE. Although external validation is needed, the cohort-specific lowest quintile VO2peak cut-points of 26.0 mL/kg/min in men and 22.2 mL/kg/min in women may aid cardiovascular risk stratification in older adults.