Improvements in exercise capacity of older adults during cardiac rehabilitation

AIMS: Cardiac rehabilitation plays a vital role in secondary prevention of cardiovascular patients. Female sex and higher age, however, are associated with non-referral to cardiac rehabilitation. Improving exercise capacity during cardiac rehabilitation is essential to reduce morbidity and mortality risks. The objective of this study was to closely examine the beneficial changes in exercise capacity of older patients of both sexes during cardiac rehabilitation and to identify the most important predictors of the change in exercise capacity. METHOD: A sample of 13,612 patients (mean age = 69.10 ± 11.8 years, 63.7% men, 19% > 80 years) was analysed. Data were prospectively assessed from 2012-2018 in six Swiss in-patient cardiovascular rehabilitation clinics. Improvement in exercise capacity measured with the six-minute walking test represents the outcome variable. Univariate and multivariate analyses, as well as the random forest method were used to estimate variable importance. RESULTS: Mean improvement in the six-minute walking test was 113.5 ± 90.5 m (men = 118.7 ± 110.0; women = 104.4 ± 93.0, Cohen's d = 0.16). The presence of heart failure, diabetes mellitus and psychiatric diagnoses was related to reduced but nonetheless clinically relevant six-minute walking test improvement. Random forest analysis suggests that baseline exercise capacity, age, time in rehabilitation and heart failure were the most important predictors for improvement in exercise capacity. Clinically relevant improvements in exercise capacity (>45 m) were also present into old age (85 years) and for both sexes. CONCLUSION: As indicated by these results, efforts need to be increased to refer eligible patients to structured rehabilitation programmes, irrespective of patients' age and sex