A target systolic blood pressure (SBP) below 120 mm Hg leads to better outcomes in ambulatory elderly patients than a target below 140 mm Hg, according to a subanalysis of SPRINT (Systolic Blood Pressure Intervention Trial).
SPRINT included a prespecified subgroup of adults ages 75 and older who had hypertension but did not have diabetes. The current study compared the effects of intensive and standard SBP targets in these 2,636 patients. "Intensive" was defined as below 120 mm Hg, while "standard" was defined as below 140 mm Hg.
The primary composite outcome for cardiovascular disease was nonfatal myocardial infarction, acute coronary syndrome that did not result in a myocardial infarction, nonfatal stroke, nonfatal acute decompensated heart failure, and death from cardiovascular causes. The secondary outcome was all-cause mortality. The results of the subgroup analysis were presented last week at the American Geriatrics Society Annual Scientific Meeting and were published online May 19 by JAMA.
The mean age of the participants was 79.9 years, and 37.9% were women. A total of 1,317 were randomly assigned to the intensive treatment group, and 1,319 were randomly assigned to the standard treatment group. Follow-up data were complete for 95.2% of patients. At a median follow-up of 3.14 years, the rate of the primary composite outcome was significantly lower in the intensive treatment group than in the standard treatment group (hazard ratio [HR], 0.66; 95% CI, 0.51 to 0.85), as was all-cause mortality (HR, 0.67; 95% CI, 0.49 to 0.91).
The overall rate of serious adverse events did not differ between the treatment groups (48.4% in the intensive therapy group vs. 48.3% in the standard therapy group; HR, 0.99; 95% CI, 0.89 to 1.11). However, the intensive therapy group had higher absolute rates of hypotension (2.4% vs. 1.4%; HR, 1.71; 95% CI, 0.97 to 3.09), syncope (3.0% vs. 2.4%; HR, 1.23; 95% CI, 0.76 to 2.00), electrolyte abnormalities (4.0% vs. 2.7%; HR, 1.51; 95% CI, 0.99 to 2.33), and acute kidney injury (5.5% vs. 4.0%; HR, 1.41; 95% CI, 0,98 to 2.04) but a lower rate of injurious falls (4.9% vs. 5.5%; HR, 0.91; 95% CI, 0.65 to 1.29).
The authors noted that SPRINT was designed to enhance recruitment of older adults but did not stratify randomization by age. In addition, they said, the generalizability of their results is limited because some elderly patients, such as nursing home residents and patients with type 2 diabetes or previous stroke, were excluded from SPRINT.
However, despite these and other limitations, the researchers concluded that treating to lower SBP targets in ambulatory adults ages 75 years and older led to better outcomes, specifically lower rates of all-cause mortality and cardiovascular events. They called for further analyses of SPRINT data to help quantify the burdens, costs, and benefits of intensive treatment but said their results "have substantial implications for the future of intensive [blood pressure] therapy in older adults because of this condition's high prevalence, the high absolute risk for cardiovascular disease complications from elevated [blood pressure], and the devastating consequences of such events on the independent function of older adults."
An accompanying editorial also detailed the limitations of both the current study and SPRINT but said the results should trigger reconsideration of optimal blood pressure goals for patients ages 75 and older. The editorialist said that current evidence supports a stepwise approach to treatment, starting with an SBP goal of less than 140 mm Hg and titrating, with careful monitoring, to a goal of 130 mm Hg if the first goal is well tolerated.
"Achieving the SBP goal of less than 130 mm Hg may be challenging for clinicians, because doing so could require use of additional medications, more careful monitoring, and more frequent clinic visits," the editorialist wrote. "Nevertheless, the important results [of the current study] cannot be discounted, and unless unexpected adverse effects are observed on further examination of the trial data, then major changes in treatment goals for patients 75 years or older with hypertension will be warranted."