Recommended revisions to the article "Prehabilitation and heart failure".

Dear Editor, Having carefully read the article submitted by Giovannini et al1, we acknowledge the authors’ efforts to explore the effects of exercise therapy in elderly patients with chronic heart failure. However, we have the following concerns with the draft manuscript: The results of the study do not sufficiently expound on Mini-Mental State Examination (MMSE); thus, we recommend that more supporting data are provided to corroborate the results. The discussion states: “In fact, some of the patients evaluated with the Mini-Mental State Examination (MMSE) showed clinical improvement”1 without elaborating upon the data used. For example, previous studies2 have reported frailty as a significant predictor of dementia, including Alzheimer’s disease, vascular dementia, and other types of dementia, in community-dwelling older adults. Lower MMSE scores have been reported to correlate directly with the quality of life (QoL), as demonstrated by the 6-minute walk test (6MWT)3. The present study will also help to clarify the relationship between the 6MWT and QoL by presenting details of cognitive function. It is recommended that the aforementioned cognitive function data are further elaborated upon, to better clarify the opacity. We suggest that the author demonstrate a group comparison for the 6MWT experiments. While there are no significant differences in comparisons within groups, past studies4 have reported significant differences in 6MWT when exercise therapy intervention is administered in elderly patients with heart failure. It will be useful to conduct a comparison between groups to clarify the opacity.