Association among mild cognitive impairment, social frailty, and clinical events in elderly patients with cardiovascular disease

Background Social support is considered a key factor for secondary prevention in patients with cardiovascular disease (CVD) and mild cognitive impairment (MCI). Recent studies have suggested the clinical importance of social frailty in CVD. Objective This study aimed to examine the association among coexistent MCI, social frailty, and clinical events in patients with CVD. Methods This study included 184 hospitalized elderly patients with CVD who participated in inpatient cardiac rehabilitation (median age, 75 years; male, 66.3%). MCI was defined as a Montreal Cognitive Assessment score of ≤25 points at discharge. Social frailty was defined using the Makizako criteria. Lack of caregiver support was also assessed as an indicator of poor social support. The Kaplan-Meier survival curve analysis and Cox regression analysis were conducted to evaluate the combined impact of MCI and social frailty or the lack of caregiver support on the composite endpoint of all-cause mortality or unplanned rehospitalization. Results The prevalence of MCI, social frailty, and lack of caregiver support were 65.2%, 70.7%, and 19.0%, respectively. There was a significant difference among subgroups by MCI and a lack of caregiver support (log-rank test, p = 0.018), and the MCI/non-caregiver group showed the worst prognosis (adjusted hazard ratio 3.96; 95% confidence interval 1.57–9.98). Likewise, MCI/social frailty group showed a significantly high event risk (3.94; 1.20–12.9) among the subgroups by MCI and social frailty. Conclusion Our results highlight the clinical importance of assessing the presence of caregiver support along with conventional social frailty for patients with CVD and MCI.