NIH Trial, Stopped Early, Supports More Intensive Blood Pressure Targets

More stringent blood pressure targets could save lives and reduce cardiovascular events, according to preliminary results from a large NIH clinical trial that was stopped early.

The SPRINT (Systolic Blood Pressure Intervention Trial) trial randomized 9,361 hypertensive patients 50 years of age or older to the standard systolic blood pressure target (when the trial began) of 140 mm Hg or lower or the more intensive target of 120 mm Hg or lower. The primary endpoint was the first occurrence of MI, ACS, stroke, heart failure, or cardiovascular death.

In a press release the NIH said that the lower target “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, as compared to the target systolic pressure of 140 mm Hg.”  During the NHLBI press conference on Friday morning trial investigator Jackson Wright said that the primary endpoint was lowered by 30% and that all cause mortality was lowered by nearly a quarter. The NHLBI declined to reveal any details about the absolute level of risk or risk reduction in the trial.

Blood pressure targets have been the subject of disagreement in recent years. At the start of the trial guidelines recommended treating most hypertensive patients to a goal of 140 mm Hg, with a lower target of 130 mm Hg or lower 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.

The NIH said that the main results of the trial will be published later this fall.

Asked to comment on the press release, Sanjay Kaul 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 said that it was necessary to see the full results but from the press release “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 <150 mm Hg for patients 60 years or older.”

This story will be updated as additional information becomes available.

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