Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial.
Level 2 - randomized trial
Individual randomized clinical trial
PubMed 30688979 · doi:10.1001/jama.2018.21442
What was done
A multicenter randomized clinical trial was conducted across 102 sites in the US and Puerto Rico among 9,361 adults aged 50 or older with hypertension and without diabetes or history of stroke. Participants were randomized to intensive systolic blood pressure control (<120 mm Hg, n = 4,678) or standard control (<140 mm Hg, n = 4,683). The primary cognitive outcome was adjudicated probable dementia; secondary outcomes included adjudicated mild cognitive impairment (MCI) and a composite of MCI or probable dementia. The blood pressure intervention was stopped early after a median of 3.34 years due to cardiovascular and mortality benefits, with total median cognitive follow-up lasting 5.11 years.
What was found
Of 9,361 randomized participants, 8,563 (91.5%) completed at least one follow-up cognitive evaluation. Adjudicated probable dementia occurred in 149 participants in the intensive group vs 176 in the standard group (7.2 vs 8.6 cases per 1,000 person-years; HR, 0.83; 95% CI, 0.67-1.04). Intensive treatment significantly reduced mild cognitive impairment (14.6 vs 18.3 cases per 1,000 person-years; HR, 0.81; 95% CI, 0.69-0.95) and the composite of MCI or probable dementia (20.2 vs 24.1 cases per 1,000 person-years; HR, 0.85; 95% CI, 0.74-0.97).
Why it matters
This trial provides randomized evidence that intensive systolic blood pressure lowering significantly reduces the incidence of mild cognitive impairment and combined cognitive decline in older adults with hypertension.
Limits
The trial was underpowered for the primary outcome of probable dementia due to early study termination and fewer than expected dementia cases. Individuals with diabetes or a prior history of stroke were excluded, and total follow-up was limited to a median of 5.11 years.
Cited by
- supports The SPRINT MIND trial found that intensive pharmaceutical lowering of high blood pressure produced a significant risk reduction for mild cognitive impairment.