Are clinical improvements in anxiety or depression associated with improvement in walking fitness following a cardiac rehabilitation programme?

Objective To investigate whether achieving minimum clinically important difference in anxiety and depression is associated with meeting minimum clinically important difference in walking fitness following cardiac rehabilitation.Methods This retrospective observational study analysed routinely collected data from the UK National Audit of Cardiac Rehabilitation. Univariate analyses were employed to investigate the baseline characteristics associated with walking fitness. Then, a logistic regression analysis was conducted to examine whether achieving the minimum clinically important difference in anxiety and depression (defined as >1.7 score improvement in the Hospital Anxiety and Depression Scale) was associated with achieving the minimum clinically important difference in walking fitness (defined as >70 m improvement in the incremental shuttle walk test) following cardiac rehabilitation.Results A total of 4585 acute coronary syndrome patients at the National Audit of Cardiac Rehabilitation underwent valid incremental shuttle walk test and the Hospital Anxiety and Depression Scale assessments before and after cardiac rehabilitation between 1 January 2021 and 30 June 2024. Patients who achieved the minimum clinically important difference for depression had 23% higher odds of meeting the minimum clinically important difference for walking fitness (OR 1.23, 95% CI 1.01 to 1.49). Compared with home-based programmes, centre-based group programmes and hybrid programmes (combining centre-based and home-based components) were associated with higher odds of achieving clinically meaningful improvement in walking fitness. Factors such as older age, female sex, physical inactivity, obesity and longer waiting times to commence cardiac rehabilitation were associated with a lower likelihood of achieving minimum clinically important difference in walking fitness, adjusting for baseline anxiety, depression and incremental shuttle walk test scores.Conclusion Clinically meaningful improvement in depressive symptoms was associated with clinically meaningful improvement in walking fitness, underscoring the relevance of addressing depression within cardiac rehabilitation.