30 Jan 2019

Results of the SPRINT MIND trial were published in the January 28 JAMA Neurology. The data indicate that reducing systolic blood pressure to about 120 mmHg over 3.25 years cut the incidence of mild cognitive impairment by 19 percent in people older than 50 during a median follow-up of 5.1 years. A trend toward less dementia in the treatment group was not statistically significant. Alzforum reported the data when Jeff Williamson, Wake Forest School of Medicine, Winston-Salem, North Carolina, presented them at the Alzheimer’s Association International Conference in Chicago last August (Aug 2018 conference news). 

In an accompanying editorial, Kristine Yaffe, University of California, San Francisco, notes that this is the first trial that has demonstrated an effective strategy for prevention of age-related cognitive impairment. SPRINT MIND was part of the larger SPRINT trial testing the effect of blood pressure (BP) lowering on cardiovascular health. Investigators halted SPRINT early because the 27 percent reduction seen in cardiovascular events was deemed so robust as to make continuation of a blinded trial unethical. SPRINT MIND continued as a cohort trial. No blood pressure medications were dispensed, only advice. “The early termination of the trial and the extended follow-up as a cohort blurs what the effect size might have been if the intervention had continued as planned,” noted Yaffe.

SPRINT MIND 2.0, an extension to the cohort trial sponsored by the Alzheimer’s Association, will determine if an effect on dementia emerges after two more years of follow-up. This does not extend the treatment period. Yaffe noted that the difference in systolic BP between treatment and control groups fell from 13 mmHg during the treatment phase to 6 mmHg during the cohort phase. Whether that difference shrinks even further with longer follow-up and how that might impact incidence MCI and dementia remains to be seen.—Tom Fagan