Major medical groups, including the American Heart Association, recommend maintaining systolic blood pressure below 140 mm Hg. But the results from a large randomized study called the Systolic Blood Pressure Intervention Trial (SPRINT) show that, for some patients at risk of cardiovascular disease, bringing systolic blood pressure below 120 mm Hg saves lives with manageable side effects.
Released simultaneously at the AHA 2015 conference and in the New England Journal of Medicine, SPRINT included over 9,000 volunteers, half of whom were assigned to standard therapy (to bring systolic pressure below 140 mm Hg) and half to intensive therapy (below 120 mm Hg). Medication regimens were individualized and relied on standard, widely available drugs: mostly diuretics, ACE inhibitors, calcium channel blockers, and angiotensin receptor blockers, with other drugs used as needed to meet the blood pressure targets.
All participants were at least 50 years old and had high blood pressure and at least one other risk factor for heart disease. The trial included older patients (75 years or older), people with chronic kidney disease, and people with a history of cardiovascular disease. The participants were also diverse: about 36% were women, 30% African American, and 11% Hispanic. People with diabetes, prior stroke or advanced kidney disease were excluded.
SPRINT was scheduled to run for five years but was stopped after less than three and a half because of the strong benefits seen in the intensive therapy group: those participants had a 43% decrease in risk of death from cardiovascular disease and a 27% decrease in overall mortality compared with the standard treatment group. This was true across all subgroups, including older participants.
“The amazing thing to me is that…to get that separation, it was only one drug difference,” said Paul Whelton, MD, the chairman of the SPRINT steering committee. That is, patients in the intensive therapy group were taking an average of 2.8 antihypertensive medications, while patients in the standard therapy group were taking an average of 1.8.
The benefits seen in the intensive therapy group did come with an increase in side effects: more patients showed an increased indication of kidney damage and an increased risk of low blood pressure episodes and fainting, though not of falls leading to injury. Overall, 4.7% of patient in the intensive therapy group and 2.5% in the standard therapy group experienced a serious adverse event. “Our impression overall is that the beneficial effects [in the intensive therapy group] seem to be much, much more important,” said Dr. Whelton. Additional data on kidney function and cognitive performance will be published in 2016.
A concurrent paper, published in the Journal of the American College of Cardiology, estimated that 16.8% of U.S. adults would meet the SPRINT eligibility criteria. A major question going forward, explained Dan Jones, MD, of the University of Mississippi and a past president of AHA, will be whether the SPRINT results can be generalized to other groups of patients, such as younger people or those with diabetes.