Depression, Socioeconomic Factors, and Ethnicity as Predictors of Cardiorespiratory Fitness Before and After Cardiac Rehabilitation

PURPOSE: To determine whether cardiac patients with psychosocial or socioeconomic problems have lower peak oxygen uptake (VO2peak) and whether these factors modify the effect of cardiac rehabilitation (CR).

METHODS: A retrospective cohort study of patients with ischemic heart disease, valvular heart disease, or heart failure referred for CR. VO2peak was assessed by a maximal cardiopulmonary exercise test. Pre-existing depression was defined by use of antidepressants and new-onset depression by a modified Primary Care Evaluation of Mental Disorders (PRIME-MD) questionnaire at CR intake. Socioeconomic status was defined by educational attainment and working status; ethnicity as Western European or non-Western European. Full data from baseline assessment were available on 1217 patients and follow-up on 861 patients.

RESULTS: Mean ± SD VO2peak before CR was 21.8 ± 6.8 mL/kg/min. After multivariable adjustment, lower VO2peak was associated with lower educational attainment, not working, and non-Western ethnicity but not with depression. Mean improvement of VO2peak following CR was 2.4 ± 4.3 mL/kg/min. After multivariable adjustment educational attainment, employment status and ethnicity were significant predictors of improvement of VO2peak while depression was not.

CONCLUSION: Education, attachment to the workforce, and ethnicity were all associated with lower VO2peak before CR, and the disparity was increased following CR. Having pre-existing depression and new-onset depression did not influence VO2peak either before or after CR. These results point to important subgroups in need of specially-tailored rehabilitation programs.