Half of them had “intensive” blood pressure control to less than 120 mmHg, and the other half were treated a goal of less than 140.
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The SPRINT trial has revealed that a target systolic blood pressure of 120 reduces by about one-quarter the rate of death, heart attack, heart failure and stroke, compared with the now recommended target pressures of 140 for people under age 60 and 150 for seniors.
The results were so striking that NIH stopped the study in August – a year earlier than planned- and released preliminary findings in September. Aside from that, the findings could also raise critical practical concerns. In the other group, patients took an average of 1.8 blood pressure drugs. There were 37 cardiovascular deaths in the intensive treatment group versus 65 in the standard treatment group (0.8% versus 1.4%, HR 0.57, 95% CI 0.38-0.85, p=0.005).
Differences in primary outcomes are large. According to the study results, about 5 percent of the patients, or 220 people, with the 120 blood pressure target had serious complications – blood pressure so low it caused severe dizziness or fainting or a reversible injury to the kidneys.
Dr Paul Whelton of Tulane University, said “overall, we deemed that the benefits far outweigh the risks” of aiming lower.
The study followed more than 9,300 patients, including a few dozen from Temple University Hospital and the Hospital of the University of Pennsylvania, for an average of more than three years.
“Success”, noted Perkovic and Rodgers, both at Australia’s University of Sydney’s George Institute for Global Health, “will require a marathon effort”.
In real life, he said, many patients do not want to take more medications and others have individual circumstances that make it unwise.
It remains to be determined whether SPRINT results will influence official medical guidelines for treating hypertension. People at higher risk, including those with diabetes, were not included.
He added that the parallel lowering in norepinephrine levels were also an intriguing candidate in relation to the blood pressure. This is a number needed to treat of about 61 to prevent a heart attack or stroke, and 90 to prevent a death. Suddenly a majority of US hypertensives would be defined as having uncontrolled hypertension.
Researchers are still analyzing the data to see if more intensive blood pressure lowering affects cognitive decline one way or the other, or has an impact on long-term kidney disease. The collaborative investigation between the University of Utah, University of Alabama at Birmingham, and Columbia University, will be published November 9 online in the Journal of the American College of Cardiology (JACC). They argued that recommendations for diabetic patients will necessarily rely on expert opinion rather than a firm evidence base, given the ambiguity and uncertainty around the ACCORD results. Again, their blood pressure was monitored.
Adults age 75 and older could potentially benefit the most from interventions based on positive SPRINT results because this age group carries the burden of hypertension: over 75 percent have the condition. “Why not continue to look at the outcomes in order to make sure?” While high BP is treatable, there is disagreement on the optimal target level. To enter the study all participants had to have a systolic BP of at least 130, be over 50, and at high risk of heart attack or stroke. “We will need to exercise caution when implementing this information”.
The AHA and ACC are now in the process of updating the last NHBLI-sanctioned JNC guideline, which was published in 2007. Drug companies donated two drugs used in the study.
Jones, Touyz, Chobanian, Munter, and Jones disclosed no relevant relationships with industry.
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The researchers found that light walking was linked to an average 10-point drop in systolic blood pressure and simple resistance activities were associated with an average 12-point drop in systolic blood pressure.
