Study shows lower systolic BP targets reduce death riskSep. 17, 2015, 9:23 AM
The initial results of a landmark clinical trial sponsored by the National Institutes of Health (NIH) indicate lowering systolic blood pressure below a commonly recommended target significantly reduces rates of cardiovascular events and lowers risk of death in a group of adults 50 years and older.
The Systolic Blood Pressure Intervention Trial (SPRINT) carefully adjusted the amount or type of blood pressure medication to achieve a target systolic pressure (the top number in a blood pressure reading) of less than 120 millimeters of mercury (mm Hg), or 130-139 mm Hg. Current clinical guidelines recommended a systolic blood pressure of less than 140 mm Hg for most adults.
Lowering systolic blood pressure to 120 mm Hg reduced rates of cardiovascular events, such as heart attack and heart failure, as well as stroke, by almost a third and the risk of death by almost a quarter.
The SPRINT study began in the fall of 2009 and includes more than 9,300 participants age 50 and older who have a combination of high blood pressure and at least one additional risk factor for heart disease. They were recruited from about 100 medical centers, including Vanderbilt University Medical Center (VUMC) and the Nashville VA Medical Center, and clinical practices throughout the United States and Puerto Rico.
It is the largest study of its kind to date to examine how maintaining systolic blood pressure at a lower than currently recommended level will impact cardiovascular and kidney diseases. The NIH reported the blood pressure intervention earlier than originally planned in order to quickly disseminate the significant preliminary results.
Vanderbilt contributed to the study design at a national level and enrolled 150 patients from Nashville, said Jamie Dwyer, M.D., associate professor of Medicine in the Division of Nephrology and Hypertension.
“We studied whether lowering blood pressure further than usual targets reduces things like heart attack and stroke. That question had not been answered until this study was designed and conducted,” Dwyer said. “The fact that it reduced the primary outcome and showed a benefit for cardiovascular events means that we now know something new about blood pressure control. This has the potential to change guidelines for blood pressure management nationwide.”
High blood pressure, or hypertension, is a leading risk factor for heart disease, stroke, kidney failure and other health problems. An estimated one in three people in the United States has high blood pressure.
“This study provides potentially lifesaving information that will be useful to health care providers as they consider the best treatment options for some of their patients, particularly those over the age of 50,” said Gary Gibbons, M.D., director of the National Heart, Lung, and Blood Institute (NHLBI), the primary sponsor of SPRINT. “We are delighted to have achieved this important milestone in the study in advance of the expected closure date for the SPRINT trial and look forward to quickly communicating the results to help inform patient care and the future development of evidence-based clinical guidelines.”
Between 2010 and 2013, the SPRINT investigators randomly divided the study participants into two groups that differed according to targeted levels of blood pressure control. The standard group received blood pressure medications to achieve a target of less than 140 mm Hg. They received an average of two different blood pressure medications. The intensive treatment group received medications to achieve a target of less than 120 mm Hg and received an average of three medications.
“Every patient needs to have his or her total medical history assessed; there will be many conditions for which these results do not apply, specifically diabetes,” Dwyer said. “Many patients will find, as the results of the study get disseminated, that their doctors will want to lower their blood pressure, and each patient will be different and individualized.
“Starting this week, once the results of the study are widely distributed, I plan to start targeting lower blood pressure where appropriate because I think doing so offers long-term beneficial effects for my patients.”
The primary results of the trial will be published within the next few months. In addition to primary sponsorship by the NHLBI, SPRINT is co-sponsored by the NIH’s National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute of Neurological Disorders and Stroke, and the National Institute on Aging.