Intensive therapy is more effective than standard blood pressure management in helping preserve brain functional connectivity in adults with hypertension (HTN).
Shah
Chintan Shah, MD, MS, currently at the Cleveland Clinic, did the work for this study at the University of Pennsylvania and along with his fellow researchers built upon the Systolic blood Pressure INTervention (SPRINT) trial, which randomized 9,361 adults with HTN to receive either standard or intensive blood pressure management.
“The original SPRINT trial demonstrated that intensive management of high blood pressure improved cardiovascular outcomes compared to standard treatment,” Dr. Shah said. “The trial served as one key piece of evidence for redefining what we now classify as hypertension; however, there was a slight increase in adverse effects in the intensive therapy group, such as syncope and hypotension, raising the question of whether intensive therapy is also safe and effective for brain health.”
Previous studies have looked at the impact of intensive treatment on cognition and brain structure, demonstrating that intensive treatment yields a protective effect, noted Dr. Shah.
“We felt it was important to continue this line of investigation to determine the impact of intensive blood pressure management on brain function by assessing changes in measures of brain functional connectivity over time in the study participants,” he explained.
In the Standard Treatment group, there are areas of negative longitudinal change in the temporal lobes (right more than left), right posterior insula, and anterior cingulate region. These areas do not show substantial change in the Intensive Treatment group.
Longitudinal Changes Noticed in Older Patients
In this multi-center trial, the investigators used resting-state functional brain MRI to assess change over time in the strength of specific brain networks, as measured using metrics of functional connectivity. They used an independent component analysis-based approach to identify resting state brain networks and compared the changes over time in 406 participants with two scans that passed quality control.
Intensive therapy was associated with a slight improvement over time in connectivity of the auditory-salience-language network (ASLN) (p=0.014) compared to standard therapy, which showed a small decrease over time, specifically in areas corresponding to the salience network. In particular, older patients and those with higher white matter lesion burden had less decline in functional connectivity of the ASLN if they received intensive treatment.
“The longitudinal change in connectivity of the default mode network demonstrated no significant difference between treatment groups,” Dr. Shah said.
Although there was a difference in the longitudinal change in connectivity of the ASLN between treatment groups, this was not related to change in overall brain volume or volume of white matter hyperintensities, Dr. Shah noted, which suggests that additional mechanisms may be involved in cognitive dysfunction in HTN patients.
The study’s results, he said, suggest that intensive blood pressure lowering is safe and beneficial for brain health, thereby providing more evidence in support of the most recent American College of Cardiology/American Heart Association guidelines for treatment of hypertension. The guidelines emphasize aiming for a lower target blood pressure and treating hypertension earlier compared to older guidelines.
“Despite the lack of beneficial effect of intensive therapy in the default mode network, these results provide some reassurance that intensive lowering of blood pressure does not demonstrate a measurable decline in mean connectivity within this network,” Dr. Shah concluded.
Access the presentation, “Longitudinal Changes In Brain Connectivity In Hypertensive Patients From The SPRINT Trial: Intensive Blood Pressure Management Is Associated With Less Decline In Connectivity,” (SSNR01) on demand at Meeting.RSNA.org.
