SPRINT participants fail to sustain long-term reductions in high blood pressure post study

Published on Monday, November 14, 2022

By: Andrea Wright Dilworth, awdilworth@umc.edu

The good news is that consistent, intensive treatment and monitoring of blood pressure results in improved, reduced numbers and significantly fewer cardiovascular deaths in high-risk patients with hypertension.

The bad news: If that consistency is not continuous, over time, blood pressure numbers will return to higher, potentially dangerous levels, with no residual benefits from earlier intensive treatment.

Those are the results of a follow-up to the national Systolic Blood Pressure Intervention Trial (SPRINT) study that initially ran from 2010 through 2015 at 102 sites. Roughly 9,300 patients were studied during the trial, with one group given a high blood pressure treatment goal of 140/90 and the other group, 120/80. Patients in both groups took prescribed medication and had their blood pressure measured every three months, with the goal of reaching the targeted respective measurements.

After five years, patients in the group whose goal was to reach 120/80 had a significantly lowered chance of dying from cardiovascular incident than the other group.

Following the groundbreaking study and after confirming other data, the American College of Cardiology and the American Heart Association lowered their blood pressure treatment goal recommendation from 140/90 to 130/80.

However, when researchers revisited those patients in a secondary analysis four-and-a-half years later, they discovered that in the years since the trial ended, those in the intensive 120/80 target group failed to sustain the lower blood pressure and were just as likely to have suffered cardiovascular incidents as those in the standard 140/90 group. The results were published in October.

“The key lesson learned is that the approach to blood pressure management being used most places now will not result in ideal results,” said Dr. Daniel Jones, dean emeritus of the School of Medicine and former president of the AHA.

While Jones was not surprised by the results, he was disappointed because they mirror contemporary trends in blood pressure control.

“We need to re-examine how our health systems approach this issue,” said Jones. “Insurers need to cover home blood pressure monitoring, telehealth contacts and community health workers’ involvement. Lifestyle management needs a better support system for practitioners and patients. Medication adjustments should be done by protocol using non-physician providers to implement including nurse practitioners, physician assistants and pharmacists.” 

Dr. Donald Clark, associate professor of medicine, division of cardiology, led a team, including Jones, that studied the effectiveness of home blood pressure telemonitoring with remote hypertension management among mostly rural, low-income participants, who received electronic tablets, monitors with Bluetooth connectivity and upper arm cuffs.

 The two-year study, published in December, saw BP rates drop on average 14 points.

“Overall, telehealth with remote telemonitoring and medication titration has been shown to lower blood pressure better than usual care,” said Clark. “Clinic-based care can be intermittent, reactive and especially challenging for patients living in rural areas. Home-based telemonitoring compliments clinic-based care and can improve management of chronic conditions like hypertension.”

The data illustrates the importance of long-term maintenance of blood pressure and the challenges of attaining targeted numbers in the real world.

The AHA, which recommends home monitoring, offers these suggestions for accurate readings:

• Be still. Don’t smoke, drink caffeinated beverages or exercise within 30 minutes. Empty your bladder and rest quietly for at least five minutes before.
• Sit correctly with your back straight and supported on a chair, with your feet flat and legs not crossed.
• Measure at the same time every day.
• Take multiple readings; record the results.
• Don’t take the measurements over clothes.

Dr. Michael Hall, chair of the Department of Medicine, said that despite the latest results, the SPRINT study proved the beneficial impact on lower blood pressure levels on cardiovascular outcomes and mortality. 

“What this follow-up study showed us was that when patients and providers revert back to routine care, blood pressure returns back to usual/higher levels and that the beneficial impact goes away,” said Hall. “When we follow guidelines and protocols closely, we can be effective. Some of this is probably due to patient factors, but I think much of this is due to health care provider inertia, and we need to take a proactive approach to improve blood pressure levels.”