How low should treatment targets for blood pressure be? Major medical groups, including the American Heart Association (AHA), recommend maintaining systolic blood pressure below 140 mm Hg. But results from the large randomized 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 Scientific Sessions 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 per cent were women, 30 per cent African American, and 11 per cent 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 per cent decrease in risk of death from cardiovascular disease and a 27 per cent decrease in overall mortality compared with the standard treatment group. This was true across all subgroups, including older participants.
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 per cent of patients in the intensive therapy group and 2.5 per cent 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 Paul Whelton, MD, chairman of the SPRINT steering committee. 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 per cent of U.S. adults would meet the SPRINT eligibility criteria.
More news from AHA 2015, including updates on cardiac resuscitation, salt intake and the clinical use of genetic risk scores, is available at now at The Beat.