Cognitive impairment measured by Mini-Cog provides additive prognostic information in elderly patients with heart failure

Abstract

Background: There has been no study elucidating whether cognitive impairment (CI) can provide additive prognostic information besides that provided by preexisting prognostic factors in elderly patients with heart failure. This study examined whether CI can provide additive prognostic information in elderly patients with heart failure.

Methods: This multicenter retrospective study included 352 patients with heart failure aged ≥75 years. We administered the Mini-Mental State Examination (MMSE) and Mini-Cog test to assess CI. The Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score was used as a model to incorporate the preexisting prognostic factors. All-cause mortality was considered the prognostic outcome.

Results: The median age was 85 years old, 47.7% were male. According to MMSE and Mini-Cog, 167 (47.4%) and 159 (45.2%) patients had CI, respectively. The agreement between MMSE and Mini-Cog was fairly low (Cohen's kappa coefficient 0.37). During the follow-up period of median 346 days, 53 patients (15.1%) died. In multivariate Cox regression analysis, CI defined by MMSE and Mini-cog were individually associated with worse prognosis in older heart failure patients even after adjustment for MAGGIC risk model and log B-type natriuretic peptide levels [CI defined by MMSE, HR: 2.05 (95%CI: 1.16-3.61); and CI defined by Mini-Cog, HR:2.57 (95%CI: 1.46-4.53)]. The area under the curve of receiver operator characteristics curve was numerically greater for Mini-Cog than for MMSE (0.59 vs. 0.52, p = 0.109). Moreover, significant net reclassification improvement was observed when CI defined by Mini-Cog, but not on CI defined by MMSE, was added to the MAGGIC score, and when Mini-Cog, instead of MMSE, was used as a CI assessment tool (0.41, p = 0.004).

Conclusions: Among elderly hospitalized patients with heart failure, CI should be considered as a critical factor for prognosis prediction. Mini-Cog is a potentially preferable tool to assess CI in terms of providing prognostically relevant information compared to MMSE.

Keywords: Cognitive impairment; Elderly; Heart failure.