Examination of clinical and psychosocial determinants of exercise capacity change in cardiac rehabilitation.

Retrospective single-program review with no comparison group of patients who did not enroll or complete cardiac rehabilitation, so it cannot show what CR did or did not change relative to usual care. Complete-case analysis excluded people with missing baseline METs (n = 59) or discharge METs (n = 90), leaving 488 of 637 eligible attendees, so results may not apply to people who did not complete full assessments. The sample was mostly non-Hispanic Caucasian (95%) and included 370 men and 118 women, and fewer than 5% had discharge METs below 3.5, limiting generalisability to women, minority groups, and patients with very low exercise capacity. Exercise capacity was estimated from treadmill METs rather than directly measured peak oxygen uptake, which may misclassify some patients. The analyses were associations, not randomised interventions, so they cannot show that age, diabetes, BMI, weight, pain, or physical functioning caused the MET changes. Patients included had completed 18 to 36 sessions, so findings may not apply to shorter or longer cardiac rehabilitation doses.

The authors reported no competing interests. The article is listed as supported by NIH extramural research.

Do not read the associations between physical function, pain, and weight change with MET gains as proof that treating these factors will improve exercise capacity. The study was observational, had no comparison group, and did not intervene on these factors.