Brain Imaging Findings Predict Blood Pressure Response to Pharmacological Treatment

Abstract

Abstract-Hypertension appears to alter brain morphology, as well as the cerebrovascular support for information processing. Because these effects might reflect progressive effects of essential hypertension on the brain, we asked whether structural and functional brain indices would predict the success of pharmacological treatment of hypertension among 45 previously unmedicated individuals. After initial structural MRI and functional positron emission tomography imaging, subjects were randomly assigned in a double-blind fashion for treatment for 1 year with either lisinopril or atenolol. Systolic and diastolic blood pressure decreases after treatment stabilization were correlated to a pretreatment index of brain aging (combined ratings of ventricle and sulcal size and white matter hyperintensities) and the pretreatment change in regional cerebral blood flow during working memory in the thalamus and posterior parietal regions of interest. In multiple regression analyses, the structural brain index and the blood flow response in the thalamus predicted 20% of the variance in the systolic blood pressure response to treatment controlling for pretreatment blood pressure, age, gender, and type and dose of medication. Alcohol use influenced the thalamic response measure, but covariates did not alter the relation between greater indices of brain aging and less successful blood pressure response to treatment. The state of the brain may be an important factor in the remediation of blood pressure. A lthough characteristics placing a person at risk for essential hypertension are well known, predictors of blood pressure (BP) response to pharmacological treatment, other than current BP, have received less attention. 1,2 Once hypertension management has begun, appropriate clinical management and compliance with the medical regimen are clearly factors in treatment outcome. 3 In addition, different treatment approaches may be more effective with, eg, diastolic hypertension versus isolated systolic hypertension; but clear clinical evidence for this has yet to be established. 4 Cerebrovascular factors are rarely considered as central to disease diagnosis or treatment but are considered only if frank cerebrovascular disease co-occurs with hypertension. 5 Increasing evidence of central nervous system involvement as either a cause or consequence of essential hypertension, 6 -12 however, led us to ask whether brain morphological indices of brain aging or regional cerebral blood flow responsivity would predict BP decline during pharmacological treatment of essential hypertension.A number of factors suggest that cerebral structure and function might relate to success of BP treatment. First, hypertension has been characterized as accelerated aging, and aging changes in the brain are well established. [13][14][15][16] Second, hypertension has been related to changes in both brain structure and cerebrovascular responsivity during information processing. 6,9,[17][18][19] Third, hypertension in mid-to-late life is associated with mild cognit...

Forebrain-dominant deficit in cerebrovascular reactivity in Alzheimer's disease

“…In addition, a small sample size may result in potential sampling bias due to heterogeneities in subject characteristics in terms of genetic and environmental factors as well as effects of medications. Our failure to find a correlation between our summation of cardiovascular risk factors and brain vascular parameters as has been reported in many other studies (Jennings et al, 2008; Iadecola et al, 2009) may be due to the insensitivity of our measure, which did not include severity of hypertension or diabetes. Additionally, the effect of cardiovascular medications may be another confounding factor in our assessment of vascular risks.…”

Brain Regional Blood Flow and Working Memory Performance Predict Change in Blood Pressure Over 2 Years

“…Successful pharmacological treatment of hypertension for a year failed to alter prospective changes in brain indices initially related to hypertension. Indeed, measures of brain structure and regional CBF (rCBF) response at baseline were positively related to the subsequent success of BP reduction 8 .…”

“…In the current work we used the magnetic resonance imaging (MRI) analog of the positron emission tomography (PET) rCBF assessments done earlier 8,9 . Arterial spin labeling (ASL) is an established technique, and its derived rCBF correlates well with PET derived rCBF 10,11,12, and with risk indicators of dementia and hypertension 13,14 .…”

Brain Indices Predict Blood Pressure Control

“…1,2 Hypertension-associated structural and functional changes in the brain begin at a surprisingly early age, and this has led to an increasing emphasis on the importance of early diagnosis and treatment. 2 The study by Jennings et al 3 in this issue of Hypertension provides further support for diagnosis and treatment as early as possible in the course of hypertension. Moreover, it offers a reasonable approach to examining the efficacy of various antihypertensive classes or agents in normalizing blood pressure.…”

“…5 Cerebral blood flow dynamics not only influence cognition, but the reverse is true. 3,5 This opens exciting new areas of research for those of us who study hypertension and cognition. The Jennings et al 3 paradigm will contribute important information to population-based studies of effective treatment strategies at different ages.…”