Intensive BP reduction may not prevent adverse cognitive outcomes

Intensive blood pressure reduction did not appear to prevent cognitive decline and dementia, according to results of a systematic review and meta-analysis published in JAMA Network Open.

“Recently, lower BP targets were advocated for the prevention of mortality and vascular events in guidelines for high-risk populations with comorbid conditions, including coronary artery disease, previous stroke, heart failure, chronic kidney disease, chronic obstructive pulmonary disease and diabetes,” Caroline Dallaire-Théroux, MD, MSc, of the division of neuroscience at the Hôpital de l’Enfant-Jésus in Canada, and colleagues wrote. “Recent guidelines from dementia experts also support that a systolic BP target of less than 120 mm Hg should be considered when deciding on the intensity of antihypertensive therapy in middle-aged and older persons with hypertension. In a recent trial, it was suggested that such an approach could have an effect on the incidence of mild cognitive impairment.”

However, controversy persists related to the ideal BP target for preventing cognitive decline, and it remains unclear whether more aggressive BP control with lower targets correlates with better cognitive outcomes vs. standard BP control.

Dallaire-Théroux and colleagues aimed to address these research gaps by searching eight databases between inception and Oct. 27, 2020, for randomized clinical trials that assessed the effect of intensive systolic BP lowering on cognitive outcomes. Cognitive decline served as the primary outcome and incidence of dementia, mild cognitive impairment, cerebrovascular events, serious adverse events and all-cause mortality as secondary outcomes.

The researchers included 16 publications from five trials, featuring 17,396 participants (mean age, 65.7 years; 60.5% men), and two additional ongoing trials. They noted unclear to high risk for bias in the five concluded trials included in quantitative analyses. Follow-up lasted for a mean of 3.3 years.

Results showed no significant association between intensive BP reduction and global cognitive performance, incidence of dementia or incidence of mild cognitive impairment upon comparison with standard treatment. However, they observed a reduction of cerebrovascular events among the intensive group without an increased risk for serious adverse events or mortality.

“The certainty of this evidence is low due to the limited follow-up period, the risk of bias of included trials and the observed statistical heterogeneity,” the researchers wrote. “Hence, current available evidence does not justify the use of lower BP targets for the prevention of cognitive decline and dementia.”