In a feasibility study, targeting antihypertensive treatment to 130/80 mm Hg rather than 140/85 mm Hg significantly increased cerebral blood flow in elderly patients.

Hypertension leads to reduced cerebral blood flow (CBF), which is associated with cognitive decline. However, aggressive blood pressure (BP) reduction in the elderly may produce cerebral hypoperfusion, resulting in falls and possibly stroke. In a proof-of-concept study, investigators recruited 37 primary-care patients aged 70 with uncontrolled clinical hypertension (defined as a systolic BP of >150 mm Hg as averaged from the second and third of 3 sitting measurements) while taking 1 antihypertensive medication. Patients were randomized to receive protocol-defined antihypertensive treatment to a target BP lower than either 130/80 mm Hg (intensive) or 140/85 mm Hg (usual). Magnetic resonance imaging to measure CBF and 24-hour ambulatory BP monitoring were performed at baseline and after 12 weeks of treatment.

At baseline, mean BP and mean CBF did not differ significantly between the two groups, and CBF did not correlate with any BP measure (clinical, ambulatory, aortic, systolic, or diastolic). At 12 weeks, mean clinical BP fell significantly from baseline in both groups; however, the reduction was significantly greater in the intensive group than in the usual group (26/17 vs. 15/5 mm Hg). Mean CBF did not change significantly from baseline in the usual group but increased significantly in the intensive-treatment group, regardless of baseline CBF. In both groups, the change in CBF correlated significantly with change in systolic BP.

Comment: In this small study, intensive blood-pressure treatment (targeted to <130/80 mm Hg) increased cerebral blood flow in elderly patients with hypertension. Whether increasing CBF by aggressive BP reduction slows cognitive decline or decreases cognitive impairment and — possibly — dementia compared with current, more conservative BP targets remains unclear. The latest revision of the National Heart, Lung, and Blood Institute‘s Joint National Committee guidelines is eagerly awaited and should shed light on BP goals in the elderly.

Source:  Journal Watch Cardiology