Intensive Blood Pressure Lowering Increases Cerebral Blood Flow in Older Subjects With Hypertension

Abstract

Abstract-Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (<130/80 mm Hg) blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, <130/80 mm Hg) or usual (target BP, <140/85 mm Hg) BP lowering for 12 weeks, with reviews every 2 weeks. CBF, determined using 3T arterial spin labeling MRI, and 24-hour ambulatory BP were performed at baseline and after 12 weeks of treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; P<0.01). Over the same period, gray matter CBF increased significantly in the intensive group (7±11 mL/min per 100 g; P=0.

Blood Pressure Is Not Associated With Cerebral Blood Flow in Older Persons

“…Furthermore, higher BP among persons with atherosclerosis was associated with a decline in CBF during 5-year follow-up, 31 and previous findings in hypertensive older persons aged ≥70 years showed that CBF increased in persons who were more intensively treated for hypertension. 32 An explanation for our results may be that in our population, consisting of older persons with mild cognitive deficits, BP stays within the range of cerebral autoregulation, whereby CBF remains constant. Because no relation with CBF was found with indicators of autonomic dysfunction, namely BP changes on standing or with BP in subgroups of persons with small vessel disease-related pathologies (prone to have disrupted cerebral autoregulation), we can only speculate that this BP range of maintained cerebral autoregulation seems relatively wide, so that CBF remains stable.…”

White Matter Hyperintensity Volume and Cerebral Perfusion in Older Individuals with Hypertension Using Arterial Spin-Labeling

“…Hypothetically antihypertensive drugs may lead to hypoperfusion, aggravating WMHs, but recent study findings make that possibility unlikely. 39,40 Although our study was conducted in an elderly population with hypertension in the Netherlands, approximately 70% in this age range have hypertension, 41 suggesting that our findings may apply to a large part of the general population. Findings of similar studies were in small or selected populations, 7,10,11,15 and may be less readily translatable to the general elderly community.…”

Reexamining the Effect of Antihypertensive Medications on Falls in Old Age

“…This line of reasoning may seem counterintuitive, since antihypertensives are thought to decrease cerebral perfusion by reducing blood pressure. It is supported, however, by a small body of evidence showing that the long-term control of high blood pressure may improve systemic and cerebral hemodynamics 7, 8, 10 . We have previously shown that the use of the calcium channel blocker Nicardipine in elderly hypertensive people with a history of coronary artery disease can reduce postprandial hypotension 25 .…”

“…In contrast, other studies have suggested that chronic blood pressure lowering with regimens that include angiotensin system-blocking medications may preserve cerebral hemodynamics 6 , increase cerebral perfusion 7-10 , and reduce the progression of cerebral white matter hyperintensities 11 , which are associated with abnormal gait and falls. 12, 13 Consistent with these reports, a recent prospective cohort study by Wong et al 14 showed a lower risk of falls among elderly community-dwelling participants taking angiotensin converting enzyme inhibitors (ACEIs) and/or angiotensin receptor blockers (ARBs).…”