Heart failure occurs when the heart is unable to support a flow of blood that meets the body’s needs, ultimately resulting in decreased oxygenation throughout the body— including the brain. Results of previous research suggest that individuals with heart failure exhibit both localized and diffuse neuropsychological deficits. The aims of this study are to meta-analytically examine a) the performance of participants with heart-failure and healthy controls on the Mini Mental State Examination (MMSE), a neuropsychological test of general cognition, and b) the role of depressive mood as a potential moderator of performance on the MMSE in these participants.

Two researchers independently searched eight databases for articles that examined the neuropsychological functioning of patients with heart failure.

Inclusion criteria identified studies that had a heart failure group with a comparable control group and reported on neuropsychological assessment for both groups. Studies were excluded if a heart failure group had any other type of major organ failure or if the comparison was between different classes of heart failure rather than between a heart failure group and healthy controls.

A meta-analysis using a random-effects model revealed a statistically significant and large effect size estimate (g= 0.727, p <.001) CI [.331, 1.123]. The heterogeneity was found to be statistically significant and in the large range, I2 = 83.027%, tau2 = .155, p < .001. A meta-regression analyzing the relationship between depressive mood and MMSE effect size estimates was statistically significant, Q residual = 8.715, df = 3, p = .03.

This study is the first to examine the relationship between depressive mood and general cognitive status (as measured by the MMSE) in participants with heart failure. The strong relationship between cognitive status and heart failure, and the role of depression in explaining a statistically significant portion of the heterogeneity in the relationship seen in primary studies, highlights the importance of accurately assessing depression when studying the effect of heart failure on cognition. Further research needs to examine the impact of depression on quality of life in patients with heart failure as potentially mediated by difficulties in cognition.