SAN DIEGO—Lowering blood pressure may provide as much benefit to elderly people with lacunar stroke as it provides to younger people with lacunar stroke, according to research presented at the 2014 International Stroke Conference. Elderly individuals appear to tolerate intensive risk factor management as well as younger individuals, and blood pressure lowering may be no more likely to cause serious adverse events among the elderly than among younger people.
Lowering systolic blood pressure to less than 130 mm Hg reduced the incidence of disabling or fatal stroke by 60% among elderly patients, said Carole L. White, RN, PhD, Associate Professor in Nursing at the University of Texas Health Science Center at San Antonio. Lowering systolic blood pressure to less than 130 mm Hg was also associated with an approximately 60% reduction in vascular death among the elderly, but it had no effect on this outcome in younger patients.
An Analysis of Elderly Participants in SPS3
Researchers in the Secondary Prevention of Small Subcortical Strokes (SPS3) trial investigated the relative efficacy of single versus dual antiplatelet therapy and higher versus lower blood pressure targets in preventing recurrent stroke. Participants in that study were randomized to a lower systolic blood pressure target of less than 130 mm Hg or a higher systolic blood pressure target of between 130 and 149 mm Hg. In a post hoc exploratory study, Dr. White and colleagues analyzed data from SPS3 to determine the safety and effectiveness of intensive systolic blood pressure management among elderly patients.
A total of 494 patients were 75 or older at entry into SPS3, and this group’s mean age was approximately 80. The elderly patients scored well on a frailty index and appeared to be “quite healthy,” said Dr. White. The elderly participants were less likely to be current smokers, more likely to report a history of hypertension at trial entry, and less likely to be diabetic than were the younger SPS3 participants. In addition, elderly patients were more likely to have multiple infarcts on MRI and to have cognitive dysfunction.
Old and Young Participants Achieved Similar Blood Pressure
The researchers found no differences in mean systolic blood pressure at trial entry or at study conclusion between elderly participants assigned to the lower blood pressure target compared with their younger counterparts. Mean achieved systolic blood pressure was 125 mm Hg for both the elderly patients and the younger group assigned to the lower systolic blood pressure target. Elderly and younger patients assigned to the higher systolic blood pressure target achieved a mean blood pressure of 137 mm Hg. Older and younger patients took an average of approximately six months to reach their target blood pressure.
At baseline, patients of all ages took a similar amount of antihypertensive medication. At the end of the study, elderly patients were taking slightly less antihypertensive medication than were younger patients, but they were still achieving good blood pressure control, said Dr. White.
Overall, elderly participants reported a higher number of minor adverse events potentially related to blood-pressure management than did younger participants. In addition, the elderly were 1.6 times more likely to report unsteadiness when standing than were younger patients.
The Study Cohort May Not Represent the General Population
One of the limitations of the researchers’ analysis is that, given their scores on the frailty index, the elderly participants in SPS3 may have been healthier than the general population of elderly individuals, said Dr. White. SPS3 was a long trial that entailed a lot of follow-up, and elderly participants missed few visits, when compared with the younger participants. The elderly cohort thus may have been highly motivated to participate in the trial, which may limit the generalizability of the results to all elderly individuals with stroke, said Dr. White. In addition, the study was underpowered to examine for differences between the oldest participants and the other elderly participants.
“The elderly need to be included in future trials to build the evidence for the best [blood pressure] target of managing these patients,” added Dr. White. “To decrease the growing stroke burden, age disparities in secondary prevention treatment must be limited."
—Erik Greb