Deaths were reduced by nearly one-quarter when systolic blood pressure was treated to a target of 120 rather than 140 mm Hg, according to a large NIH-sponsored study comparing standard blood pressure treatment with more-intensive lowering of systolic blood pressure. The lower blood pressure group also saw a 30% reduction in the composite primary composite endpoint of cardiovascular events, stroke, and cardiovascular death.
The magnitude of the effect of the lower blood pressure target prompted the study’s data safety monitoring board to end the study early, said officials from several National Institutes of Health agencies at a telebriefing. The study was unblinded in August 2015, and a full report of the primary outcome measures will come in a paper due out by the end of the year, they said.
The Systolic Blood Pressure Intervention Trial, or SPRINT, is a 100-site trial that enrolled more than 9,300 people in the United States and Puerto Rico aged at least 50 years with high blood pressure and at risk for cardiovascular disease; those with diabetes were excluded. Patients were randomized to a standard treatment target of 140 mm Hg or less, or to a more intensive 120 mm Hg.
SPRINT participants received evidence-based treatment with a variety of antihypertensives, with the intervention arm requiring an average of almost three medications, compared with just under two for the less-intensive treatment arm.
Against a backdrop of uncertainty in the literature about what the target systolic blood pressure should be for those with hypertension and at risk for cardiovascular events or kidney disease, the study provides compelling evidence that more-aggressive blood pressure lowering is important. “More-intensive management of blood pressure can save lives,” said Dr. Gary Gibbons, director of the National Heart, Lung, and Blood Institute. This is good news, he said, since about one in three Americans has high blood pressure, and only about half of those 70 million currently have their blood pressure under control.
Dr. Jackson T. Wright Jr., SPRINT study lead and director of the clinical hypertension program at Case Western Reserve University in Cleveland, also emphasized that intensive blood pressure management can prevent the cardiovascular complications of hypertension. Though subgroup analysis is ongoing, the effect seems robust and consistent across age groups, sex, and ethnicity, he said. SPRINT, he said, also “offers an excellent opportunity to examine the tolerability and safety of the lower target.” The first look at the safety data shows that the more-intensive treatment is well tolerated, though data analysis is ongoing, he said.
Dr. Suzanne Oparil, director of the vascular biology and hypertension program at the University of Alabama-Birmingham, said, “This is a time of enlightenment.” The previous absence of compelling data played a part in the debate surrounding blood pressure levels that should be used in guidance documents, and Dr. Gibbons and Dr. Wright both emphasized that they would expect the forthcoming primary outcomes paper to have an impact on guideline-writing bodies. Dr. Wright said, however, “We are not providing guidance for providers or patients right now. The study was just unblinded a little less than 3 weeks ago.”
In 2014, the group of experts who had constituted the JNC 8 panel, a team assembled in 2008 by NHLBI to update official U.S. hypertension management guidelines, set the target blood pressure for the general population aged 60 years or older to less than 150/90 mm Hg, a major break from long-standing practice to treat such patients to a target systolic pressure of less than 140 mm Hg (JAMA. 2014;311:507-20). These guidelines, released after SPRINT began, remain controversial.
The SPRINT MIND trial, tracking the relationship between systolic blood pressure and cognitive impairment or dementia, is ongoing. The study is also still collecting data about kidney function in study participants.
The study was funded by the National Institutes of Health. Two drug companies, Takeda and Arbor, provided some medication for the trial.
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