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NIH Trial Supports More Intensive BP Targets
More stringent blood pressure targets could save lives and reduce cardiovascular events, according to preliminary results from a large National Institutes of Health (NIH) clinical trial.
SPRINT, the Systolic Blood Pressure Intervention Trial, randomized 9,361 hypertensive patients 50 years of age or older to what was the standard systolic blood pressure target when the trial began — less than 140 mm Hg — or the more intensive target of less than 120 mm Hg. The lower target reduced rates of a first occurrence of myocardial infarction, acute coronary syndrome, stroke, heart failure, or cardiovascular death by 30% and the risk of death by almost 25% when compared to the target systolic pressure of less than 140 mm Hg.
The NIH did not provide more specific numbers or respond to requests for absolute risk reduction for that primary endpoint, MedPage today reported.
Blood pressure targets have been the subject of disagreement for years. At the start of the trial, guidelines recommended treating most hypertensive patients to a goal of less than 140 mm Hg, with a lower target of less than 130 mm Hg for patients with kidney disease or diabetes.
Patients in the standard treatment group received an average of two separate antihypertensive agents, compared with three in the intensive treatment group. Previous observational studies found that risk increases once blood pressure rises above 115/75 mm Hg, but the benefit of a treatment strategy based on that finding has not been previously demonstrated in a randomized controlled trial.
Asked to comment on the NIH press release, Sanjay Kaul, MD, MPH, of Cedars-Sinai Heart Institute in Los Angeles, said that “the treatment effect has to be large and statistically persuasive for the trial to be stopped prematurely. They must have seen a pronounced effect on mortality or an irreversible CV endpoint.” The finding will surely “ignite yet another controversy regarding BP treatment targets,” he said.
Sripal Bangalore, MD, of New York University Langone Medical Center in New York City, said it would be necessary to see the full results. However, he said, “it appears that the intensive-BP-lowering group was a clear winner.” He said the finding “will be practice-changing.” Since the trial enrolled more than 2,500 patients who were 75 years of age or older, it “clearly puts to rest the controversial JNC 8-recommended target of less than 150 mm Hg for patients 60 years or older.”
That target from a 2014 report from some members of a panel appointed to update the Joint National Committee recommendations is commonly but unofficially known as JNC 8 and was not endorsed by the NIH’s National Heart, Lung, and Blood Institute (NHLBI).
Study investigator Suzanne Oparil, MD, of the University of Alabama at Birmingham, writing committee member for both that report and a subsequent American Health Association/American College of Cardiology (AHA/ACC) statement re-emphasizing the 140 mm Hg target in coronary artery disease, said the SPRINT findings will help settle the controversy and influence guidelines.
“This is a time of enlightenment,” she said at a press telebriefing convened by the NHLBI, calling the data “powerful new information that needs to be digested. But I think we need to avoid having patients jump on it and demand that their blood pressure be normalized. That would be premature.”
SPRINT senior investigator Jackson Wright, MD, PhD, of University Hospitals Case Medical Center in Cleveland, said at the briefing he was “quite convinced all will be impressed” when the full data are published. He predicted they “will have a significant impact on what will finally be recommended but [he] would not make a recommendation at this time.”
The NIH said that the main results of the trial will be published this fall.
The safety data from SPRINT and subgroup analyses for older adults are still being prepared. While the first look indicated the intensive treatment target was well tolerated, the risks will be looked at much more closely, Wright noted. “However, I think we have to keep in mind that any adverse profile will have to be compared against the dramatic reduction in cardiovascular events and a 25% reduction in mortality.”
Source: MedPage Today; September 11, 2015.