Cognitive Change After Left Ventricular Assist Device Implantation: A Case Series and Systematic Review

Background: Chronic cerebral hypoperfusion is a po-tential mechanism that causes cognitive impairment in patients with heart failure. Cognitive impairment in this population is associated with an increased mortality and poorer quality of life. Understanding the etiopatho-genesis of cognitive impairment is crucial to developing effective treatment. A left ventricular assist device (LVAD) is a durable mechanical circulatory support device that restores systemic perfusion in patients with heart failure, potentially reversing cerebral hypo-perfusion and cognitive impairment. Objective: This case series and systematic review examines the effect of LVAD implantation on cognition in patients with heart failure. Methods: We report a case series of 4 LVAD recipients at a tertiary academic center who underwent preimplant and postimplant cognitive testing. We also conducted a systematic review of studies with adult re-cipients of a continuous-flow LVAD whose cognition was measured before and after implantation. We searched Medline, EMBASE, SCOPUS, and the Cochrane li-brary (start of database to July 16, 2021) for longitu-dinal, peer-reviewed studies written in English. Results: Cognitive improvement after LVAD implantation was observed in the case series, with improvement on pho-nemicfluency and digit symbol coding assessments. Two out of 4 cases in the case series improved on Clinical Dementia Rating: one from moderate dementia to mild cognitive impairment and another from mild cognitive impairment to unimpaired. Seven studies were included in the systematic review and were heterogeneous regarding cognitive tests employed, follow-up period, and measured outcomes. Montreal Cognitive Assessment and Trail-Making Test Part B were used most commonly. Cognitive improvement was reported in all 7 studies with at least 1 study reporting statistically significant im-provements in each the following cognitive domains: delayed and immediate recall, executive function, visuo-spatial function, verbal function, attention, and process -ing speed. Most studies had small sample sizes and lacked a control group. Conclusions: LVAD implanta-tion appears to be associated with improved cognition. Adequately powered, prospective studies are needed to examine the effect of LVAD on cognitive function in patients with heart failure. Additionally, studies that directly examine cerebral blood flow in conjunction with cognitive assessment are needed to establish the rela-tionship between the reversal of cerebral hypoperfusion and improved cognition.