NEW ORLEANS — Reducing systolic blood pressure with intensive treatment limited the growth of subcortical white matter disease in a randomized trial, but it didn’t improve cognitive or mobility function, a researcher said here.
White matter hyperintensity accrual was 40% less among patients in the intensive treatment group than in the standard treatment group after 3 years, results of the randomized, open-label INFINITY trial showed.
But that wasn’t the study’s primary endpoint. For measures of cognitive function and gait speed, the two co-primary outcomes, intensive antihypertensive treatment failed to show a significant benefit, reported William White, MD, of the University of Connecticut in Farmington, here at the American College of Cardiology (ACC) annual meeting.
Although the primary outcome is important, the data presented here are also meaningful, noted panel discussant Eileen Handberg, PhD, of the University of Florida in Gainesville, during a press conference.
After 80 years of bad lifestyle and bad blood pressure control, the brain will change, and it’s unrealistic to think that change can be reversed in just 3 years, she said. “I think the fact that you were able to demonstrate a mechanistic change in … brain matter intensity is important.”
In presenting the results, White noted, “Subcortical microvascular disease of the brain, represented by white matter hyperintensity on magnetic resonance images, is associated with functional decline in older people with hypertension.”
Handberg also suggested the study was important for demonstrating that older patients can tolerate intensive antihypertensive treatment. “Our fear of them falling [due to] hypotension is a little bit unwarranted. I think we exclude people from aggressive blood pressure lowering because of this unrealized fear in the elderly.”
INFINITY randomized 199 patients ages 75 or older (mean age was 81) in equal numbers to standard or intensive blood pressure-lowering treatment for 3 years, to achieve systolic pressure targets of 145 or 130 mm Hg, respectively.
All patients showed signs of white matter hyperintensity lesions on MRI at baseline and had hypertension defined as clinic-measured systolic pressure of >170 mm Hg or 150-170 mm Hg while taking at least one antihypertensive drug. Hypertension was confirmed with ambulatory measurement showing systolic blood pressure ≥140 mm Hg over a 24-hour period.
Participants were excluded if they had clinically impaired gait, unstable chronic neurologic conditions, like Parkinson’s disease, dementia, or stroke, and cardiovascular conditions.
Doctors worked with patients until they reached the target blood pressure via ambulatory monitoring.
Patients receiving intensive therapy had fewer major CV events, including stroke, arrhythmia, hospitalization from heart failure, and myocardial infarction, compared with the standard-treatment group. No differences were found between the two groups for syncope or falls.
White said the small patient numbers were a limitation. As well, he said, “It is probable that 3 years was too short in duration to observe functional differences between the intensive- and standard-treatment groups.”
Sequential reaction time was the only cognitive endpoint to show improvement in the intensive-treatment cohort, White said. Some secondary mobility measures showed trends favoring intensive treatment. However, there was no difference at all between groups in change from baseline in gait speed, the prespecified primary mobility endpoint.
The study was funded by the National Institute of Aging of the National Institutes of Health and the Lowell Weicker General Clinical Research Center at the University of Connecticut.
White disclosed relationships with the National Institutes of Health.