Update on the SPRINT trial: Preliminary results pan out

Deepak Bhatt, MD, MPH

In a previous blog, I reported on the preliminary results from SPRINT, a clinical trial that examined whether a systolic blood pressure target of 120 mm Hg or less would be better than a target of 140 mm Hg in patients with hypertension (high blood pressure). The National Heart, Lung, and Blood Institute of the National Institutes of Health issued a press release with the exciting results. Now, the full paper has been published in The New England Journal of Medicine, and the results appear to be as practice-changing at it initially seemed, demonstrating a stricter blood pressure goal can reduce the likelihood of dying. In the world of medicine, this is really big news.

The SPRINT researchers randomly assigned 9,361 patients at increased cardiovascular risk (though without diabetes) with a systolic blood pressure of 130 mm Hg or higher to either standard treatment or to intense treatment. Standard treatment meant a target of less than 140 mm Hg for the systolic blood pressure (the top number) and intense treatment meant a target of less than 120 mm Hg. On average, the patients in the trial were followed for 3.26 years, at which point the trial was stopped earlier than planned because researchers felt the results were too compelling to allow the study to continue. There was a 25% reduction in the rate of cardiovascular complications, including events such as heart attack, heart failure, and stroke. There was a 27% reduction in the risk of death.

It is important to note that very few interventions in medicine actually reduce the risk of death. Among physicians who lead clinical trials, this would be considered a home run.

To achieve the greater degree of blood pressure reduction, on average, three medications were needed instead of two. Not surprisingly (to any physician), this resulted in more side effects such as low blood pressure, fainting, kidney failure, and electrolyte abnormalities on blood tests. Practically speaking, that means to achieve the impressive results seen in this study, patients will need to take more medications and have to be followed carefully by their doctors. Otherwise, the benefits demonstrated in this research setting may not be fully reproducible in real-world practice, and the risk of serious side effects may be even higher.

Also, the results don’t apply to everyone at increased cardiovascular risk who has high blood pressure. For example, patients with diabetes, heart failure, a previous stroke, or younger than 50, were not enrolled in the trial. Those with a very high blood pressure (systolic of 180 mm Hg or greater) were also excluded from the study. There were many patients 75 years of age or older in the trial—which is great, because many studies exclude older people—but none of these elderly study volunteers lived in nursing homes or assisted-living facilities.

What should patients with high blood pressure do now? Making an appointment to see your primary care physician to determine if you need more aggressive blood pressure management makes sense. There is no emergency to do this, as the adverse effects of high blood pressure in the range studied in this trial typically take time to manifest. But I wouldn’t suggest waiting until your annual check-up either — the beneficial results seen in the SPRINT trial started to become apparent at approximately one year. And it may take a few visits to get on a medication regimen that lowers blood pressure without causing too many side effects. The good news is that there are many generic blood pressure medications, so with some trial and error, many patients can achieve the degree of blood pressure control noted in this study.

The reality, though, is that in the United States and worldwide, many patients have blood pressure that is not controlled even to the previously recommended goals. So, the major remaining challenge is how we can make sure that patients similar to those in the trial benefit from this major advance in our understanding of the treatment of high blood pressure. Current estimates in a paper just published in the Journal of the American College of Cardiology suggest that in the U.S., the results of SPRINT would directly apply to roughly 8% of adults and approximately half are not being treated for high blood pressure—that works out to over 8 million people!

Identifying those people, some of whom may even have a blood pressure in the 130s, will not be easy, as they may not regularly seek medical care. Therefore, the SPRINT study also implies that even if you don’t have a diagnosis of high blood pressure, you should know what your blood pressure is and talk with your doctor about how to assess risks and benefits to you of treatment to achieve what is the optimal blood pressure goal for you.

Related Information: Harvard Heart Letter

Comments:

  1. radhia slama

    Nice write up. Thanks for this post.

  2. mdpookie

    And what about JNC 8?