The effects of left ventricular geometry on cortical cerebral microinfarcts and cognition

Abstract

Introduction: Left ventricular hypertrophy (LVH) is associated with increased risk of cardiovascular events, cognitive impairment, and mortality. However, the associations between LVH and cortical cerebral microinfarcts (CMI) and the underlying mechanisms involved are less known. This study examined the associations of LVH geometric patterns with CMI and cognition. In addition, we assessed if the association between LVH and cognition was mediated by CMI. Methods: Participants were recruited from a memory clinic cohort in Singapore. All participants underwent comprehensive physical and medical examination, echocardiography assessment, 3T brain MRI scans, and neuropsychological assessments. Echocardiography was conducted to assess left ventricular mass index (LVMI) and relative wall thickness (RWT) parameters to identify patients with left ventricular hypertrophy (LVH). Participants were further categorized into left ventricular geometric patterns which included normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Brain MRI scans were graded for the presence of CMI. Cognition was assessed by the Mini-Mental State Examination, Montreal Cognitive Assessment, and the National Institute of Neurological Disorders and Stroke–Canadian Stroke Network harmonization battery to classify participants as having no cognitive impairment (NCI), cognitive impairment no dementia (CIND), or dementia. Results: 261 participants were included in the study after assessing for eligibility. The mean age was 75 (6.7) years, majority were female (58%), and of Chinese ethnicity (87%). Participants with concentric hypertrophy were independently associated with presence of CMI (OR=3.38, 95% CI 1.06,10.55), and global cognition (ß=-0.95, p=0.03). The effects of concentric hypertrophy on global cognition were fully mediated by the presence of CMI (Figure 1). Discussion: Elevated LVMI and RWT in concentric hypertrophy is independently associated with presence of CMI and global cognition. The association between concentric hypertrophy and global cognition was mediated by the presence of CMI. Left ventricular geometric patterns could be used as a risk stratification tool to identify patients at risk of developing CMI and cognitive impairment.