Blood-brain barrier disruption in response to blood pressure changes in adults with hypertension: a serial MRI study.

Background

Loss of blood-brain barrier (BBB) integrity is observed in patients with hypertension and is hypothesized to contribute to cerebral small vessel disease (SVD) pathogenesis. Blood pressure increase and decrease within individuals and the effects on BBB integrity have never been examined.

Objectives

To examine BBB leakage in middle-aged patients with hypertension following subsequent blood pressure increase and decrease.

Methods

The Hyperintense study included hypertensive adults who temporarily discontinued antihypertensive medication for diagnostic purposes. MRI was done at three timepoints: before medication withdrawal (visit 1), during withdrawal (visit 2) and after medication restart (visit 3). BBB integrity was measured with 3T dynamic contrast-enhanced (DCE)-MRI. We assessed leakage rate Ki [min-1] and blood plasma volume Vp. Linear regression was used to examine association between changes in blood pressure and BBB leakage.

Results

Fourteen patients with hypertension (mean age 48.2 ± 4.5 years; 36% female) were included. After medication withdrawal, blood pressure increased in 11/14 participants (79%). Increase in blood pressure between visit 1 and visit 2 was associated with increased Ki in white (WM) (β = 0.683, P = 0.007) and grey matter (GM) (β = 0.587, P = 0.027) and Vp in the GM (β = 0.666, P = 0.009). Following medication restart, blood pressure decreased in seven participants, with Ki decreasing in four of them. There was no association between decrease in blood pressure and Ki or Vp between visit 2 and visit 3.

Conclusions

Blood pressure increase was associated with increased BBB leakage. Reduction in BBB leakage following medication restart was observed in most, but not all participants. This suggests that BBB leakage is dynamic and influenced by blood pressure.