Intensive Blood Pressure Management May Reduce the Risk of MCI
The SPRINT MIND substudy examined whether intensive blood pressure management affected the risk of probable all-cause dementia or MCI
The investigators examined data for 9,361 SPRINT subjects who were age 50 or older (mean age, 68) and had at least one cardiovascular risk factor. Approximately 30% of participants were black, and 10% were Hispanic. The primary outcome was incident probable dementia. Secondary outcomes were MCI and a composite of MCI and probable dementia.
In SPRINT, physicians could choose any appropriate antihypertensive regimen, but were encouraged to use drugs with the strongest evidence of cardiovascular benefit. These drugs included thiazide-type diuretics, loop diuretics, and beta-adrenergic blockers. About 90% of the drugs used during the study were generic.
Subjects were seen monthly for the first three months. During this time, medications were adjusted to achieve the target blood pressure. After the third month, subjects were examined every three months. Medications could be adjusted monthly.
Results Favored Intensive Treatment
At one year, mean systolic blood pressure was 121.4 mm Hg in the intensive-treatment group and 136.2 mm Hg in the standard treatment group. Treatment was stopped early after a median follow-up of 3.26 years because of the observed cardiovascular disease benefit.
The SPRINT MIND study did not meet its primary end point. Incident probable all-cause dementia occurred in 175 people in the standard care group and 147 people in the intensive treatment group. The difference between groups in the rate of 17% risk reduction was not statistically significant.
The results for both secondary end points were significant, however. Incident MCI occurred in 348 participants in the standard treatment group and 285 participants in the intensive treatment group. The difference indicated a statistically significant 19% risk reduction associated with intensive treatment. Furthermore, intensive treatment significantly reduced the risk of the combined secondary end point of MCI and probable dementia by 15%. In all, 463 participants in the standard care group met this end point, compared with 398 in the intensive care group.
The imaging study included 454 subjects who had brain MRI at baseline and at four years after randomization. Total brain volume did not change, said Ilya Nasrallah, MD, Assistant Professor of Radiology at the University of Pennsylvania in Philadelphia. Patients in the intensively managed group, however, had 18% lower white matter lesion load than those in the standard care group.
White matter lesions often indicate small-vessel disease, which is associated with vascular dementia and, perhaps, Alzheimer’s disease. Most patients with Alzheimer’s disease have a mixed dementia that includes a vascular component, said Dr. Carrillo.
