AHA calls for randomized trials assessing hypertension, cognition

Adults with hypertension in middle age may have issues with cognitive function, particularly executive function and processing speed, according to a scientific statement from the American Heart Association.

The statement, which was published online Oct. 11 in Hypertension, also mentioned that the association between hypertension later in life and cognition was less clear. Further, the authors noted that results of randomized trials have been unclear as to whether treating adults with high blood pressure at any stage of their life improves cognition.

“We know treating high blood pressure reduces the risk of heart diseases such as heart attacks, congestive heart failure and stroke, and it is important to continue treating it to reduce the risks of these diseases,” Costantino Iadecola, MD, chair of the writing committee and a neurology professor and director of the Brain and Mind Research Institute at Weill Cornell Medicine, said in a news release. “However, we need randomized controlled studies—which do prove cause and effect—to determine if treating high blood pressure, especially in middle age, will also decrease the risk of cognitive impairment later in life.”

An estimated 30 million to 40 million people in the world have dementia, and that number is expected to triple by 2050. Meanwhile, an estimated 80 million people in the U.S. and 1 billion people worldwide have hypertension, which targets the brain and is the leading cause of global disease burden.

The writing committee included authors with expertise in vascular pathophysiology, epidemiology, neuroimaging, neuropathology and cognitive science pertaining to the effects of hypertension on the brain.

After reviewing the studies and data, the group found there was not enough information to make evidence-based recommendations. However, the authors did provide overviews on the effects of hypertension on cerebrovascular structure and function, the cognitive domains targeted by hypertension, observational studies that evaluated hypertension and cognition, the interaction between hypertension and other risk factors, the relationship between hypertension and Alzheimers disease, and hypertension treatment during people’s lifetimes.

“Observational studies suggest that hypertension causes an accumulating burden of vascular injury across all stages of life, but paradoxically, the end stages of vascular disease in frail elderly patients may be marked by low [blood pressure],” they wrote. “Such considerations support the use of antihypertensive therapy throughout middle age and then continued efforts at judicious control of [blood pressure] in elderly patients who appear likely to tolerate it. Results of randomized, clinical trials are awaited to prove the likely hypothesis that good control of [blood pressure] and other vascular risk factors across the life span will help to stem the tide of cognitive impairment and dementia that would otherwise be expected with a continually aging population.”

The authors said that results of the SPRINT-MIND trial could answer some of the numerous questions pertaining to hypertension and cognition. That sub-study of the SPRINT examined 2,800 adults with high blood pressure and sought to evaluate the effects of lowering systolic blood pressure on cognitive function.

“Despite numerous outstanding questions and caveats, personalized treatment of hypertension, taking into account age, sex, APOE genotype, metabolic traits, comorbidities, etc, remains a most promising and eminently feasible approach to safeguard vascular health and, as a consequence, brain heath,” they wrote. “Antihypertensive drugs are generally safe and widely available, but there is still much to be learned about how to best use them over the life course in the presence of comorbidities and whether specific classes of drugs may confer cognitive benefits beyond [blood pressure] lowering. New discoveries in the cellular and molecular pathology of the cerebrovascular tree and associated cells, coupled with the use of new imaging tools, biomarkers and genomic-proteomic approaches in clinical trials, offer the prospect to address these unanswered questions and to develop new treatments to mitigate the devastating impact of hypertension on cognitive health.”