Adults with hypertension who were at least 75 years old had significantly lower rates of death and fatal and nonfatal major cardiovascular events if they were treated to a systolic blood pressure target of less than 120 mm Hg compared with those treated to a target of less than 140 mm Hg.
Lead researcher Jeff D. Williamson, MD, MHS, of the Wake Forest School of Medicine in Winston-Salem, N.C., and colleagues published their results online in JAMA on May 19.
The findings were also presented at the American Geriatrics Society annual scientific meeting in Long Beach, Calif.
The researchers mentioned that 75 percent of adults in the U.S. who are older than 75 years old have hypertension. However, they added there was no consensus as to the systolic blood pressure treatment target.
For this subgroup analysis, they evaluated data from the randomized SPRINT trial, which found that patients treated to a systolic blood pressure target of less than 120 mm Hg had a 25 percent lower relative risk of major cardiovascular events and death compared with patients treated to a target of less than 140 mm Hg.
The mean age of patients was 79.9 years old, and 37.9 percent were women. Of the 2,636 patients, 1,317 were randomized to a systolic blood pressure target of less than 120 mm Hg and 1,319 were randomized to the normal blood press target.
After a median follow-up period of 3.14 years, significantly fewer patients in the intensive treatment group had the primary cardiovascular disease outcome compared with those in the standard treatment group (102 vs. 148). The primary cardiovascular disease outcome was a composite of nonfatal MI, acute coronary syndrome not resulting in an MI, nonfatal stroke, nonfatal acute decompensated heart failure and death from cardiovascular causes.
In addition, 73 patients in the intensive treatment group and 107 patients in the standard treatment group died during the follow-up period, which was significantly different. There was no difference in the cardiovascular disease death rates.
Further, the rates of serious adverse events were similar: 48.4 percent in the intensive group vs. 48.3 percent in the standard group.
For these patients, the researchers said a treatment goal of less than 120 mm Hg reduced cardiovascular disease by 33 percent and mortality by 32 percent.
“Translating these findings into numbers needed to treat suggests that a strategy of intensive [blood pressure] control for 3.14 years would be expected to prevent 1 primary outcome event for every 27 persons treated and 1 death from any cause for every 41 persons treated,” they wrote. “These estimates are lower than those from the overall results of the trial due to the higher event rate in persons aged 75 years or older. In addition, exploratory analysis suggested that the benefit of intensive [blood pressure] control was consistent among persons in this age range who were frail or had reduced gait speed.”
The researchers cited a few limitations of their analysis, including that the SPRINT trial did not stratify patients based on age. The study also did not enroll older adults living in nursing homes, people with type 2 diabetes or prevalent stroke and people with symptomatic heart failure.
“Therefore, the results reported in this study among persons aged 75 years or older do not provide evidence regarding treatment targets in these populations,” they wrote. “Individuals with these conditions also represent a subset of older persons at increased risk for falls.”