Age-Related Differences for Cardiorespiratory Fitness Improvement in Patients Undergoing Cardiac Rehabilitation.

Objective: We investigated age-related differences for peak oxygen uptake (peak VO ₂ ) improvement with exercise training during cardiac rehabilitation (CR).
Patients and Methods: This was a retrospective cohort study of the Mayo Clinic Rochester CR program including adult patients who attended CR (≥1 session) for any eligible indication between 1999 and 2017 and who had a cardiopulmonary exercise test pre and post CR with VO ₂ data (peak respiratory exchange ratio ≥1.0). Younger (20-49 yrs), midlife (50-64 yrs), and older adults (≥65 yrs) were compared using ANOVA for delta and percent change in peak VO ₂ ; and percentage of peak VO ₂ responders (>0% change).
Results: 708 patients (age: 60.8 ± 12.1 years; 24% female) met inclusion criteria. Delta and percent change in peak VO ₂ was lower for older adults (1.6 ± 3.2 mL.kg.min ^-1 ; 12 ± 27%) compared with younger (3.7 ± 4.0 mL.kg.min ^-1 , p < 0.001; 23 ± 28%, p = 0.002) and midlife adults (2.8 ± 3.8 mL.kg.min ^-1 , p < 0.001; 17 ± 28%, p = 0.04). For midlife, delta change, but not percent change in peak VO ₂ was significantly lower ( p = 0.02) compared with younger. Percentage of responders was only different between older and younger (72 vs. 86%; p = 0.008). Sensitivity analyses in non-surgical patients showed similar differences for delta change, and differences in percent change remained significant between older and younger adults (10 ± 20% vs. 16 ± 18%; p = 0.04).
Conclusions: In CR patients, older adults had lower improvement in cardiorespiratory fitness than younger and midlife adults. While excluding surgical patients reduced age-related differences, older adults still had lower cardiorespiratory fitness improvement during CR. These findings may have implications for individualizing CR programming in aging populations to reduce future cardiovascular risk.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Taylor, Medina-Inojosa, Chacin-Suarez, Smith, Squires, Thomas, Johnson, Olson and Bonikowske.)