Heart Rate, Brain Imaging Biomarkers and Cognitive Impairment in Older (≥63 years) Women

Am J Cardiol. 2020 Aug 15:129:102-108. doi: 10.1016/j.amjcard.2020.05.030. Epub 2020 May 26.

Abstract

Evidence on the relations between heart rate, brain morphology, and cognition is limited. We examined the associations of resting heart rate (RHR), visit-to-visit heart rate variation (VVHRV), brain volumes and cognitive impairment. The study sample consisted of postmenopausal women enrolled in the Women's Health Initiative Memory Study and its ancillary MRI sub-studies (WHIMS-MRI 1 and WHIMS-MRI 2) without a history of cardiovascular disease, including 493 with one and 299 women with 2 brain magnetic resonance imaging (MRI) scans. HR readings were acquired annually starting from baseline visit (1996-1998). RHR was calculated as the mean and VVHRV as standard deviation of all available HR readings. Brain MRI scans were performed between 2005 and 2006 (WHIMS-MRI 1), and approximately 5 years later (WHIMS-MRI 2). Cognitive impairment was defined as incident mild cognitive impairment or probable dementia until December 30, 2017. An elevated RHR was associated with greater brain lesion volumes at the first MRI exam (7.86 cm3 [6.48, 9.24] vs 4.78 cm3 [3.39, 6.17], p-value <0.0001) and with significant increases in lesion volumes between brain MRI exams (6.20 cm3 [4.81, 7.59] vs 4.28 cm3 [2.84, 5.73], p-value = 0.0168). Larger ischemic lesion volumes were associated with a higher risk for cognitive impairment (Hazard Ratio [95% confidence interval], 2.02 [1.18, 3.47], p-value = 0.0109). Neither RHR nor VVHRV were related to cognitive impairment. In sensitivity analyses, we additionally included women with a history of cardiovascular disease to the study sample. The main results were consistent to those without a history of cardiovascular disease. In conclusion, these findings show an association between elevated RHR and ischemic brain lesions, probably due to underlying subclinical disease processes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Brain / diagnostic imaging*
  • Brain / pathology
  • Brain Ischemia / diagnostic imaging
  • Brain Ischemia / epidemiology*
  • Cognitive Dysfunction / diagnostic imaging
  • Cognitive Dysfunction / epidemiology*
  • Dementia / diagnostic imaging
  • Dementia / epidemiology*
  • Estrogen Replacement Therapy
  • Female
  • Gray Matter / diagnostic imaging
  • Gray Matter / pathology
  • Heart Rate / physiology*
  • Hippocampus / diagnostic imaging
  • Hippocampus / pathology
  • Humans
  • Magnetic Resonance Imaging
  • Middle Aged
  • Organ Size
  • Postmenopause
  • Proportional Hazards Models
  • White Matter / diagnostic imaging
  • White Matter / pathology