The
National Institutes of Health (NIH) plans to add about 1,750
participants over the age of 75 to its upcoming Systolic Blood Pressure
Intervention Trial (SPRINT).
The idea is to determine whether a lower blood pressure range in
older adults will reduce cardiovascular and kidney diseases, age-related
cognitive decline, and dementia.
"No large-scale clinical trial has examined the impact of
aggressively lowering systolic blood pressure among older adults," said
Susan B. Shurin, M.D., acting director of the NIH's National Heart,
Lung, and Blood Institute (NHLBI).
Specific areas of study
"The SPRINT study and the senior expansion address four of the 10
common causes of death and disability in adults over 75 years: heart
disease, stroke, kidney failure, and dementia," Shurin pointed out. "The
addition of these participants promises to provide useful scientific
and public health information on a large and growing segment of the
population."
Current clinical guidelines recommend maintaining a systolic blood
pressure -- the top number in a blood pressure reading -- of less than
140 millimeters of mercury (mm Hg) for healthy adults of all ages and
130 mm Hg for adults with kidney disease or diabetes. Two previous
trials found that reducing systolic blood pressure in older participants
reduced stroke, heart failure, and overall cardiovascular events by
more than 30 percent.
SPRINT will evaluate the safety and potential benefits or risks of
maintaining systolic blood pressure at either less than 140 mm Hg
(standard group) or less than 120 mm Hg (treatment group) -- a lower
target than currently recommended or studied in previous trials.
Researchers will treat study participants with commonly available
medications to achieve their target blood pressure. Those in the
treatment group will take an average of three to four medications. Those
in the standard group will take an average of two medications.
Participants will be seen in clinics every month at the beginning of
the study and less frequently as they reach their blood pressure
targets. The study will include standard tests for determining the
health of the heart, kidneys, and brain.
The National Institute of Neurological Disorders and Stroke (NINDS)
and the National Institute on Aging (NIA) support SPRINT Memory and
Cognition IN Decreased Hypertension (SPRINT-MIND), a substudy of SPRINT
that focuses on the impact of lowering systolic blood pressure on
cognitive decline and development of dementia.
All-encompassing
The study will also include brain imaging to measure treatment
effects on brain structure. Participants in SPRINT-Senior, as the study
expansion is known, will also be included in SPRINT-MIND.
SPRINT-Senior will be conducted through the existing SPRINT clinical center networks:
• Case Western Reserve University School of Medicine, Cleveland (Principal Investigator: Jackson T. Wright, M.D., Ph.D.)
• Department of Veterans Affairs, VA Medical Center, Memphis (Principal Investigator: William C. Cushman, M.D.)
• University of Alabama at Birmingham (Principal Investigator: Suzanne Oparil, M.D.)
• University of Utah, Salt Lake City (Principal Investigator: Alfred K. Cheung, M.D.)
• Wake Forest University Baptist Medical Center, Winston-Salem, N.C. (Principal Investigator: David C. Goff, Jr., M.D., Ph.D.
The coordinating center for the study is Wake Forest Baptist (Principal Investigator: David Reboussin, Ph.D.).
Announced in 2009, SPRINT is a nine-year study to be conducted in
over 70 clinical sites across the United States. Including the 1,750 new
SPRINT-Senior participants, approximately 9,250 people age 55 years or
older are expected to be enrolled.
Participants will have systolic blood pressure of 130 mm Hg or higher
as well as a history of cardiovascular disease; be at high risk for
heart disease by having at least one additional risk factor, such as a
history of smoking or a high blood cholesterol level; or have chronic
kidney disease. Over 40 percent of the SPRINT participants are expected
to have chronic kidney disease.
SPRINT and SPRINT-Senior are examples of comparative effectiveness
research, which compares different interventions or strategies to
prevent, diagnose, treat, and monitor health conditions in clinical
settings. SPRINT enrollment will begin this fall.
The first two years of SPRINT-Senior will cost $12.7 million, and is
being funded by the economic stimulus. NIH is providing $30.1 million
for the remaining six years of the project.