Does an exercise-based rehabilitation program improve objective and subjective indices of exercise tolerance over time in patients following AMI, CABGS, or valve surgery?
Objective and subjective indices of exercise tolerance improve at different rates during cardiac rehabilitation, highlighting the need to measure both to accurately document recovery.
PURPOSE: Exercise-based rehabilitation programs improve effort tolerance in patients with cardiovascular disease. Little is known regarding the time course of recovery of objective and subjective indices of exercise tolerance. METHODS: Twenty-six patients were studied at 0, 4, 8, and 12 weeks following early entry into rehabilitation following acute myocardial infarction (AMI), coronary artery bypass graft surgery (CABGS), or valve surgery. Exercise tolerance was assessed objectively by percent predicted cycle power output (%PO), and subjectively by a self-efficacy questionnaire for ambulatory (ASE) and muscular (MSE) items and by a disease-specific, health-related, quality-of-life questionnaire (HRQL). RESULTS: With the exception of percent predicted cycle power output, all exercise tolerance measures improved throughout the rehabilitation program. Extrapolation of recovery curves suggest that recovery to 85% predicted can be achieved in 10, 11, 18, and 21 weeks for a disease-specific, health-related, quality-of-life questionnaire, self-efficacy questionnaire for ambulatory items, muscular items, and power output, respectively. CONCLUSIONS: The data demonstrate that evaluation of both objective and subjective indices of exercise tolerance may be important in documenting outcomes of participation in structured rehabilitation programs. The time course of recovery of objective and subjective indices of exercise tolerance may not be highly correlated.
Foster et al. (1995) studied this question.