Lower than optimal systolic BP may not further reduce CV risk

Once systolic BP is less than 140 mm Hg, there may not be any further benefit in lowering it to below 120 mm Hg, according to new data from the Atherosclerosis Risk in Communities Study.

“Our study found that the optimal [systolic BP] range for people with hypertension is [120 mm Hg to 139 mm Hg], which significantly reduces the risk of stroke, heart attack or heart failure,” researcher Carlos J. Rodriguez, MD, MPH, said in a press release. “These findings suggest you don’t need to go lower than that to have the benefits.”

Rodriguez, of Wake Forest Baptist Medical Center, and colleagues studied 4,480 participants from the Atherosclerosis Risk in Communities (ARIC) Study with hypertension but without CVD at baseline from 1987 to 1989. They evaluated incident CV events among participants stratified into three groups: those with systolic BP ≥140 mm Hg (elevated group), those with systolic BP between 120 mm Hg and 139 mm Hg (standard group) and those with systolic BP ≤120 mm Hg (low group).

Systolic BP was measured at baseline and during three triennial visits.

The primary outcome was a composite of HF, ischemic stroke, MI and CHD-related death. Median follow-up was 21.8 years.

After adjustment for baseline age, sex, diabetes, BMI, cholesterol level, smoking and alcohol intake, Rodriguez and colleagues found that the elevated group developed incident CV events at a much higher rate compared with the low group (adjusted HR=1.46; 95% CI, 1.26-1.69).

However, there was no difference in incident CV event-free survival between the standard group and the low group (HR=1; 95% CI, 0.85-1.17). Adjusting for BP medication use and diastolic BP did not change the results.

“This calls into question that lower is better,” Rodriguez said in the press release. He noted that the SPRINT clinical trial, which is underway, will confirm or refute these findings.

In a related editorial, Paul Arthur James, MD, of the University of Iowa, wrote that the results “illustrate the marginal benefits of adding more medications to achieve lower BPs in the general population.”

A contributing factor to the findings, James wrote, could be that the rate of medication use was just 46% in the elevated group vs. 90% in the standard group and 99% in the low group. “It indicates the need to find new ways to increase BP control in diverse and high-risk populations,” he wrote. “We must stop relying on traditional clinical models that do not support patients who have difficulty taking their medications.”

For more information:

James PA. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2014.1000.

Rodriguez CJ. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2014.2482.

Disclosure: The study was funded by the NHLBI. The researchers and James report no relevant financial disclosures.