Cerebral perfusion in untreated, controlled, and uncontrolled hypertension

Abstract

This study evaluated the association between systemic arterial blood pressure and cerebral perfusion in 740 participants of the UK's largest tri-ethnic study with measurements of cerebral blood flow (CBF) performed using arterial spin labelling MRI. A significant negative correlation between blood pressure, age and CBF was observed across the patient cohort. The lowest CBF values were recorded in the group of patients with hypertension that were prescribed with anti-hypertensive drugs, but uncontrolled on medication. These findings confirm that hypertension is associated with reduced cerebral perfusion and highlight the importance of blood pressure control for the benefit of maintaining brain blood flow.

Keywords: Cerebral blood flow; MRI; brain; hypertension; perfusion.

Figure 1.

Cerebral perfusion in untreated, controlled, and uncontrolled hypertension. Summary plots illustrating the relationships between grey (a) and white (b) matter perfusion and systolic arterial blood pressure (SBP). Linear fit regression line is shown ± 95% CI. Participant’s medication status groups are indicated: (i) individuals with normal blood pressure, not taking any anti-hypertensive medication with a SBP of <130 mmHg; (ii) patients with untreated hypertension, not taking any anti-hypertensive medication with a SBP ≥130 mmHg; (iii) patients with controlled hypertension, taking anti-hypertensive medication with a SBP of <130 mmHg; and (iv) patients with hypertension, prescribed with anti-hypertensive drugs, but uncontrolled on medication with a SBP of ≥130 mmHg. (c) The relationship between age and cerebral perfusion measured by ASL. Linear fit regression line is shown ± 95% CI and (d,e) summary data illustrating the differences in grey and white matter perfusion between 4 groups of patients. Groups were compared using ANCOVA with age, BMI, and sex as covariants and Tukey’s multiple comparison correction for post-hoc analysis. Violin plots show arithmetic mean (central point)  ± SD with the outline illustrating kernel probability density. Indicated P values were obtained in comparison to the normotensive group data.