Mild cognitive impairment in patients with acute heart failure does not limit the effectiveness of early phase II cardiac rehabilitation.

Abstract

Cardiac rehabilitation (CR) is commonly performed in patients with heart failure (HF) with mild cognitive impairment (MCI). However, whether MCI diminishes the benefit of early phase II CR is unclear. This study aimed to clarify whether MCI diminishes the benefit of early phase II CR in patients hospitalized for HF. The design of the work is a case-control study. All HF patients who underwent CR in acute care hospitals in Japan from April 2016 to March 2021. Among the 574 patients who underwent CR, 204 were included in this study. Exclusion criteria were age <65 years, dependence for activities of daily living (ADLs) prior to admission, diagnosis of dementia or delirium, mini-mental state examination (MMSE) score at the commencement of CR<19, missing data, in-hospital death, and transfer to another department during hospitalization. Patients were divided into two groups, those with MCI (MCI group, N.=134) and those without MCI (non-MCI group, N.=70), based on MMSE score at the commencement of CR. Cognitive impairment was defined as a score of <19. MCI was defined as an MMSE score between 19 and 26, and normal cognitive function was defined as MMSE >26. The primary outcomes were the 6-minute walking distance (6MWD), Barthel Index (BI), and Short Physical Performance Battery (SPPB). All patients underwent guideline-based CR programs. On admission, MCI patients had significantly lower BI (P<0.01, confidence interval [CI]: 4.9-20.4) and SPPB (P<0.01, CI: 1.1-3.1), despite being independent for ADLs before admission. In addition, 6MWD (P<0.01, CI: 31.2-97.2), BI (P=0.01, CI: 1.0-8.4), and SPPB (P<0.01, CI: 0.6-2.5) were significantly lower in the MCI group at the time of discharge. However, after propensity score matching to adjust for baseline characteristics, no significant differences in any primary outcome were found between the two groups. The BI, SPPB, and 6MWD improvements due to CR were similar, regardless of MCI. Our results may inform the selection of appropriate rehabilitation interventions for patients with HF and MCI.