Cardiorespiratory Fitness Benefits of Long-Term Maintenance-Phase Cardiac Rehabilitation in Males and Females: A Retrospective Cohort Study

Purpose: This study investigated if associations exist between enrolment delay and VO(2)peak over five years of maintenance-phase cardiac rehabilitation (CR) in males and females. Method: Data were extracted from the records of participants who had enrolled for >= 1 year in CR and completed >= 2 cardiopulmonary exercise tests. Mixed model analyses examined VO(2)peak trajectories for up to five years of enrolment. Interactions between enrolment delay x enrolment duration, baseline age x enrolment duration, and baseline VO(2)peak x enrolment duration were explored for inclusion in the model. Results: The charts of 151 males (aged 63.9 +/- 9.4 y) and 32 females (aged 65.3 +/- 9.0 y) were included in the analyses. The enrolment delay following a cardiovascular event was 1.8 +/- 3.0 years for males and 1.3 +/- 1.7 years for females. No associations were found between enrolment delay x enrolment duration on VO(2)peak in males (beta[SE], 0.07[0.05]; 95% CI -0.02, 0.16, p = 0.12) or in females (beta[SE], 0.07[0.13]; 95% CI -0.18, 0.33, p = 0.57), but predicted trajectories suggest clinically significantly improvements in VO(2)peak (range, 1.3 to 1.6 mL/kg/min). Conclusions: Early enrolment in CR is recommended and encouraged, but the benefits of long-term CR are possible despite delays.