Umea, Sweden—New guidelines published by the American Heart Association (AHA) and the American College of Cardiology (ACC) called for treating with lifestyle changes—and sometimes medication—those with blood pressure of 130/80 mm Hg or higher, instead of the previous 140/90 mm Hg threshold.
New Swedish research calls the basis of the new guidelines into question, however. That study published recently in JAMA Internal Medicine supports the older levels, arguing that hypertension treatment does not reduce death or cardiovascular disease in healthy individuals with a systolic blood pressure below 140.
Umeå University researchers conducted a systematic review to reach that conclusion. Specifically, their study contradicts findings from the Systolic Blood Pressure Intervention Trial (SPRINT), which was among the studies used by the AHA and ACC in developing their new guidelines. SPRINT, published in 2015, went even farther than the new guidelines, promoting cardiovascular disease reduction with a goal of less than 120 mm Hg.
The Umeå study also suggests that benefits of hypertension treatment at lower blood pressure levels are limited to trials with coronary heart disease patients.
“Our findings are of great importance to the debate concerning blood pressure treatment goals,” emphasized lead author Mattias Brunström, MD, of the Department of Public Health and Clinical Medicine at Umeå University.
The meta-analysis employed data from 74 randomized clinical trials that involved more than 300,000 patients. For the study, primary preventive studies were considered separately from those concerning coronary heart disease (CHD) or stroke patients.
Results indicate that, at least for previously healthy people, treatment effect was dependent on the level of high blood pressure. Study authors point out that, if systolic blood pressure was above 140 mm Hg, treatment reduced the risk of death and cardiovascular disease, but, for levels below 140 mm Hg, treatment did not appear to affect mortality or the risk of initial cardiovascular events.
Specifically, the analysis determined:
• In trials with baseline systolic blood pressure (SBP) 160 mm Hg or above, treatment was associated with reduced risk for death (RR, 0.93; 95% CI, 0.87-1.00) and a substantial reduction of major cardiovascular events (RR, 0.78; 95% CI, 0.70-0.87).
• For baseline SBP ranging from 140 to 159 mm Hg, the association of treatment with mortality was similar (RR, 0.87; 95% CI, 0.75-1.00), but the association with major cardiovascular events was lessened (RR, 0.88; 95% CI, 0.80-0.96).
• In trials with baseline SBP below 140 mm Hg, treatment was not associated with reductions in mortality (RR, 0.98; 95% CI, 0.90-1.06) or major cardiovascular events (RR, 0.97; 95% CI, 0.90-1.04).
• In trials including patients with previous CHD and mean baseline SBP of 138 mm Hg, treatment was associated with reduced risk for major cardiovascular events (RR, 0.90; 95% CI, 0.84-0.97) but not with improved survival (RR, 0.98; 95% CI, 0.89-1.07).
“Several previous meta-analyses have found that blood pressure lowering treatment is beneficial down to levels below 130 mm Hg,” Brunström added. “We show that the beneficial effect of treatment at low blood pressure levels is limited to trials in people with coronary heart disease. In primary preventive trials, treatment effect was neutral.”
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New Swedish research calls the basis of the new guidelines into question, however. That study published recently in JAMA Internal Medicine supports the older levels, arguing that hypertension treatment does not reduce death or cardiovascular disease in healthy individuals with a systolic blood pressure below 140.
Umeå University researchers conducted a systematic review to reach that conclusion. Specifically, their study contradicts findings from the Systolic Blood Pressure Intervention Trial (SPRINT), which was among the studies used by the AHA and ACC in developing their new guidelines. SPRINT, published in 2015, went even farther than the new guidelines, promoting cardiovascular disease reduction with a goal of less than 120 mm Hg.
The Umeå study also suggests that benefits of hypertension treatment at lower blood pressure levels are limited to trials with coronary heart disease patients.
“Our findings are of great importance to the debate concerning blood pressure treatment goals,” emphasized lead author Mattias Brunström, MD, of the Department of Public Health and Clinical Medicine at Umeå University.
The meta-analysis employed data from 74 randomized clinical trials that involved more than 300,000 patients. For the study, primary preventive studies were considered separately from those concerning coronary heart disease (CHD) or stroke patients.
Results indicate that, at least for previously healthy people, treatment effect was dependent on the level of high blood pressure. Study authors point out that, if systolic blood pressure was above 140 mm Hg, treatment reduced the risk of death and cardiovascular disease, but, for levels below 140 mm Hg, treatment did not appear to affect mortality or the risk of initial cardiovascular events.
Specifically, the analysis determined:
• In trials with baseline systolic blood pressure (SBP) 160 mm Hg or above, treatment was associated with reduced risk for death (RR, 0.93; 95% CI, 0.87-1.00) and a substantial reduction of major cardiovascular events (RR, 0.78; 95% CI, 0.70-0.87).
• For baseline SBP ranging from 140 to 159 mm Hg, the association of treatment with mortality was similar (RR, 0.87; 95% CI, 0.75-1.00), but the association with major cardiovascular events was lessened (RR, 0.88; 95% CI, 0.80-0.96).
• In trials with baseline SBP below 140 mm Hg, treatment was not associated with reductions in mortality (RR, 0.98; 95% CI, 0.90-1.06) or major cardiovascular events (RR, 0.97; 95% CI, 0.90-1.04).
• In trials including patients with previous CHD and mean baseline SBP of 138 mm Hg, treatment was associated with reduced risk for major cardiovascular events (RR, 0.90; 95% CI, 0.84-0.97) but not with improved survival (RR, 0.98; 95% CI, 0.89-1.07).
“Several previous meta-analyses have found that blood pressure lowering treatment is beneficial down to levels below 130 mm Hg,” Brunström added. “We show that the beneficial effect of treatment at low blood pressure levels is limited to trials in people with coronary heart disease. In primary preventive trials, treatment effect was neutral.”
« Click here to return to Weekly News Update.
