Prevalence of Cognitive Impairment in Individuals with Vascular Surgical Pathology: a Systematic Review and Meta-Analysis

Objective: A significant proportion of vascular surgery patients may have undiagnosed cognitive impairment; however, its true prevalence and impact on outcomes are unknown. The aim of this review was to estimate the prevalence of cognitive impairment among individuals with clinically significant vascular surgical pathology and investigate its associations with post-operative outcomes in those undergoing vascular surgery. Methods: MEDLINE, EMBASE, EMCare, CINAHL, PsycINFO, and Scopus were searched for relevant studies. Included studies assessed cognitive function among individuals with either symptomatic vascular surgical pathology, or disease above threshold for intervention, using a validated cognitive assessment tool. The primary outcome measure was prevalence of cognitive impairment. Secondary outcomes included incidence of post-operative delirium (POD). Two reviewers independently extracted relevant study data and assessed risk of bias (ROBINS-E or RoB 2 tool). Prevalence (%) of cognitive impairment was calculated for individual studies and presented with 95% confidence intervals (CI). Prevalence data from comparable studies were pooled using the Mantel-Haenszel method (random effects model) for separate vascular disease types. Certainty of effect estimates was assessed using the GRADE criteria. Results: Twenty-four studies (2 564 participants) were included in the systematic review, and nine studies (1 310 participants) were included in the meta-analyses. The prevalence of cognitive impairment was 61% (95% CI 48 - 74; 391 participants; low certainty) in studies including multiple vascular surgical pathologies, 38% (95% CI 32 - 44; 278 participants; very low certainty) in carotid artery disease, and 19% (95% CI 10 - 33; 641 participants; low certainty) in those with intermittent claudication. Lower cognitive assessment scores were associated with POD (five studies; 841 participants), but data were not suitable for pooling. Conclusion: Screening elective vascular surgery patients for cognitive impairment may be appropriate given its high prevalence, and the association of worse cognition with POD, among individuals with clinically significant vascular surgical pathology.