Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN.
Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN.
J Am Heart Assoc. 2018 Jun 26;7(13):e009041. doi: 10.1161/JAHA.118.009041.
Left ventricular (LV) hypertrophy is associated with cerebrovascular disease and cognitive decline. Increased LV mass index is a subclinical imaging marker that precedes overt LV hypertrophy. This study relates LV mass index to white matter microstructure and cognition among older adults with normal cognition and mild cognitive impairment.
Vanderbilt Memory & Aging Project participants free of clinical stroke, dementia, and heart failure (n=318, 73±7 years, 58% male, 39% mild cognitive impairment) underwent brain magnetic resonance imaging, cardiac magnetic resonance, and neuropsychological assessment. Voxelwise analyses related LV mass index (g/m) to diffusion tensor imaging metrics. Models adjusted for age, sex, education, race/ethnicity, Framingham Stroke Risk Profile, cognitive diagnosis, and apolipoprotein E-ε4 status. Secondary analyses included a LV mass index×diagnosis interaction term with follow-up models stratified by diagnosis. With identical covariates, linear regression models related LV mass index to neuropsychological performances. Increased LV mass index related to altered white matter microstructure (<0.05). In models stratified by diagnosis, associations between LV mass index and diffusion tensor imaging were present among mild cognitive impairment participants only (<0.05). LV mass index was related only to worse visuospatial memory performance (β=-0.003, =0.036), an observation that would not withstand correction for multiple testing.
In the absence of prevalent heart failure and clinical stroke, increased LV mass index corresponds to altered white matter microstructure, particularly among older adults with clinical symptoms of prodromal dementia. Findings highlight the potential link between subclinical LV remodeling and cerebral white matter microstructure vulnerability.
左心室（LV）肥大与脑血管疾病和认知能力下降有关。LV 质量指数增加是一种亚临床影像学标志物，先于明显的 LV 肥大。本研究将 LV 质量指数与认知正常和轻度认知障碍的老年人的白质微观结构和认知联系起来。
范德比尔特记忆与衰老项目的参与者没有临床中风、痴呆和心力衰竭（n=318，73±7 岁，58%男性，39%轻度认知障碍）接受了脑部磁共振成像、心脏磁共振成像和神经心理学评估。体素分析将 LV 质量指数（g/m）与弥散张量成像指标相关联。模型调整了年龄、性别、教育、种族/民族、弗雷明汉中风风险评分、认知诊断和载脂蛋白 E-ε4 状态。次要分析包括 LV 质量指数×诊断的交互项，并对诊断分层进行后续模型分析。在相同的协变量下，线性回归模型将 LV 质量指数与神经心理学表现相关联。LV 质量指数增加与白质微观结构改变相关（<0.05）。在按诊断分层的模型中，LV 质量指数与弥散张量成像之间的关联仅存在于轻度认知障碍参与者中（<0.05）。LV 质量指数仅与较差的视觉空间记忆表现相关（β=-0.003，=0.036），这一观察结果在经过多次测试校正后并不成立。
在没有明显心力衰竭和临床中风的情况下，LV 质量指数增加与白质微观结构改变有关，尤其是在有前驱性痴呆临床症状的老年人中。这些发现强调了亚临床 LV 重塑与大脑白质微观结构脆弱性之间的潜在联系。
