This week, full results of SPRINT—the Systolic Blood Pressure Intervention Trial—were presented at the Scientific Sessions of the American Heart Association in Orlando, Florida. Called the most important blood pressure trial in 40 years, SPRINT asked what would happen if older adults with high blood pressure and one other health risk got enough medicine to push their systolic BP to 120 mm Hg instead of 140 mm Hg. Researchers found that this aggressive approach meant patients had far fewer heart attacks, strokes, and cardiac deaths. Here are 5 things to know:
1. These results really are a big deal.
It’s not too often that results of a clinical trial become so clear that the scientists stop it early—because it would be unethical to withhold treatment from the patients who are getting less therapy. That’s what happened in SPRINT. The trial, organized by the National Institutes of Health (NIH), was expected to run 4 to 5 years, but it stopped August 20, 2015 after just 3.26 years. At that point, the group being treated more aggressively had 25% fewer deaths and 30% fewer cardiovascular events.
2. The patients in the trial were a diverse group and the positive results held up.
The study involved more than 9300 adults over age 50 who had high blood pressure and at least one other health risk, such as chronic kidney disease or existing cardiovascular disease. They were a diverse group demographically, and NIH made sure to include a group of patients over age 75. The positive results held up across all the subgroups—and that’s important. One concern about giving too much blood pressure medication to adults with renal problems is that it would further damage their kidneys. The study found that aggressive treatment did find some signs of kidney problems for patients who didn’t start out with them, but those with existing kidney disease showed no change. Benefits clearly outweighed the risks, researchers said.
3. The goals were reached with standard therapies.
Researchers said that in general, it took 1 additional drug to get patients to the lower goal. The group treated to the traditional target of under 140 mm Hg reached an average systolic BP of 136.2 mm Hg after 1 year, while the group treated to the more aggressive goal of 120 mm Hg reached an average systolic BP of 121.4 mm Hg. Paul K. Whelton, MB, MD, MSc, chair of the SPRINT steering committee and an epidemiologist from Tulane University, said during a press conference that researchers used standard therapies already on the market.
4. Guidelines likely won't be updated immediately to reflect the results.
There’s every sense that they will, but an editorial in the New England Journal of Medicine that appeared alongside the study suggested some judgment is needed. Giving more medication demands resources. A 120 mm Hg systolic BP target for patients with risk factors is a good idea, but no solution should rely solely medicine without least trying to modify patients’ diet, exercise, and tobacco use. An initiative announced at the sessions by AHA and the American Medical Association called Target BP mentioned the current guideline of 140 mm Hg, but said committees are furiously reviewing SPRINT to see if updates are needed. Guidelines for patients with diabetes have always been lower, at 130 mm Hg for systolic BP.
5. The results of the SPRINT trial could be far reaching.
Millions, possibly. An analysis that appeared in the Journal of the American College of Cardiology in late October calculated how many people would affected if the criteria used to recruit patients for the SPRINT study were applied across the US population. It found that 51% of those who need hypertension treatment probably aren’t getting therapy right now. That's some 8.6 million people.