Effect of cardiovascular diseases on brain functional changes and cognition: a systematic review of fMRI studies

Abstract

Background Functional magnetic resonance imaging (fMRI) is a useful tool to evaluate brain inefficiencies secondary to cardiovascular diseases (CVDs); nevertheless, limited fMRI studies have been conducted to investigate the effect of CVD on brain functional changes and cognition. This systematic review aims to explore, synthesise, and report the fMRI outcomes and cognitive changes in patients with CVDs. Methods Two reviewers independently searched published literature until August 2023 on ScienceDirect, PubMed, Web of Science, and ClinicalTrials.gov. A total of 22 eligible studies were considered for full-text screening, of which 9 were included in this review. The methodological quality was assessed by mixed methods appraisal tool and reported as empirically fair. Results Among the 312 CVD subjects, aged between 49.90 ± 6.10 to 72.20 ± 5.70 years, majority had coronary heart diseases (n = 153, 40.04%) and hypertension (n = 188, 60.26%), and approximately half of them were females (n = 157, 50.32%). Based on the qualitative synthesis, CVD subjects have increased cognitive decline and poorer task performance (reduced Mini-Mental State Examination/Montreal Cognitive Assessment, lower mean 2-back task scores, and slower reaction time). Results also indicate impaired brain activity at supplementary motor area associated with poor ejection fraction, and reduced default mode network suppression linked to high low-density lipoprotein cholesterol; lower regional homogeneity and amplitude of low-frequency fluctuation values; and reduced functional connectivity. Conclusion It can be extrapolated that CVDs tend to alter brain network connectivity and result in cognitive impairment. However, for future imaging studies, more stringent and homogenous demographic data are highly recommended.