Disparate effects of improving aerobic exercise capacity and quality of life after cardiac rehabilitation in young and elderly coronary patients.

PURPOSE: Although cardiopulmonary exercise variables predict prognosis, functional capacity, and quality of life (QoL) in patients with coronary artery disease (CAD), these variables have not been assessed fully before and after exercise training in elderly with CAD. Therefore, the purpose of this study was to determine the impact of formal Phase II cardiac rehabilitation and exercise training programs on cardiopulmonary variables and QoL in elderly and younger CAD patients.
METHODS: The authors analyzed consecutive patients before and after Phase II cardiac rehabilitation and exercise training programs, and compared exercise cardiopulmonary data and data from validated questionnaires assessing QoL (MOS SF-36) and function in 125 younger patients (< 55 years; mean 48 +/- 6 years) and 57 elderly (> 70 years; mean 78 +/- 3 years).
RESULTS: At baseline, elderly patients had lower estimated aerobic exercise capacity (-27%; P < 0.001), peak oxygen consumption (VO2) (-19%; P < 0.01), and anaerobic threshold (-10%; P < 0.05), as well as total function scores (-11%; P < 0.01) and total QoL scores (-5%; P = 0.06). Commonly used prediction equations greatly overestimated aerobic exercise capacity compared with precise measurements using cardiopulmonary testing both before (+23% and +12% in younger and elderly patients, respectively) and after the exercise training programs (+51% and +31% in younger and elderly patients, respectively), and more so in younger compared with older patients. After rehabilitation, the elderly had significant improvements in estimated aerobic exercise capacity (+32%; P < 0.0001), peak VO2 (+13%; P < 0.0001), anaerobic threshold (+11%; P = 0.03), total function scores (+27%; P < 0.0001), and total QoL scores (+20%; P < 0.0001). Although younger patients had greater improvements in estimated aerobic exercise capacity (+44% versus +32%; P = 0.08), peak VO2 (+18% versus +13%; P < 0.01), and anaerobic threshold (+17% versus +11%; P = 0.07), the elderly had statistically greater improvements in both function scores (+27% versus +20%; P = 0.02), and total QoL scores (+20% versus +14%; P = 0.03).
CONCLUSIONS: These data confirm the benefits of precisely determining aerobic exercise capacity by cardiopulmonary function, especially to determine the benefits of an exercise training program. In addition, these data using cardiopulmonary exercise tests and validated assessments of quality of life demonstrate the disparate effects of cardiac rehabilitation programs on improvements in aerobic exercise capacity and QoL in young and elderly with CAD.