Study Suggests Caution in SPRINT-Like BP Targets in Elderly

By Megan Brooks

NEW YORK (Reuters Health) - A new analysis finds an increased risk of falls and syncope in elderly community-dwelling patients with hypertension treated to a target systolic blood pressure of < 120 mm Hg.

In the Systolic Blood Pressure Intervention Trial (SPRINT), treating hypertensive adults aged 75 and older to reach a systolic BP target less than 120 mm Hg (compared with less than 140 mm Hg) led to a reduction in cardiovascular events and death without a significant increase in injurious falls or syncope.

Dr. Donal Sexton of Trinity College Dublin and colleagues set out to determine if individuals meeting inclusion criteria for SPRINT outside the clinical trial context are similar to trial participants, especially with regard to risk for adverse outcomes.

As reported in JAMA Internal Medicine July 17, they compared rates of injurious falls and syncope in 407 community-dwelling adults 75 and older from The Irish Longitudinal Study on Ageing (TILDA) with rates in 1,319 patients in the standard-care group of SPRINT.

All TILDA subjects were white, as opposed to 75% of SPRINT participants. Orthostatic hypotension at baseline was more common in TILDA than SPRINT participants (12.3% vs. 9.4%). More SPRINT patients had a history of cardiovascular disease (23.4% vs. 17.7%), aspirin use (58.0% vs. 39.3%) and statin use (52.8% vs. 39.1%), suggesting a higher cardiovascular risk profile, the authors note. Mean follow-up was 3.4 years in both groups.

While the TILDA participants were undergoing standard care in the community, 111 (27.3%) reported an injurious fall and 54 (13.3%) reported syncope. In SPRINT, 73 of 1,319 participants (5.5%) reported injurious falls and 32 (2.4%) reported syncope.

“Although SPRINT was powered for cardiovascular outcomes and mortality, that does not necessarily mean that it was adequately powered to detect an increase in injurious falls,” Dr. Sexton told Reuters Health by email. “If the participants of SPRINT were representative of community-dwelling elders then one would expect the injurious-falls rate in the standard-care arm to be similar to that in TILDA. However, we found that injurious falls and syncope were five times higher in community-dwelling participants of TILDA than they were in the standard-care arm of SPRINT.”

Dr. Sexton said there are many potential reasons for the differences such as better general care in a randomized trial and early stoppage of the trial leading to under-ascertainment of adverse outcomes.

“The message for clinicians is that the findings of SPRINT with regard to injurious falls and syncope may not be externally valid or generalisable to community-dwelling elders. While the benefits of SPRINT are not in dispute, in clinical practice the balance of risks and benefits of intensive BP lowering ought to be individualized,” said Dr. Sexton.

Reached for comment, Dr. Usman Baber, Director of Clinical Biometrics, Icahn School of Medicine at Mount Sinai in New York said: “These are interesting findings, suggesting a higher rate of injurious falls and syncope in a 'real-world' cohort of older community-dwelling adults compared with those enrolled in a large-scale clinical trial.”

“Patients in the TILDA cohort,” he noted, “differed in several important parameters compared to those in SPRINT. For example, TILDA participants were more often female and displayed higher baseline systolic and diastolic blood pressure. Hence, caution should be exercised in extending the results of the SPRINT trial to such a population with a higher risk of falls and syncope, as suggested by the authors. Nevertheless, these data do not contradict the findings of the SPRINT trial, but rather reinforce the need for clinicians to examine the findings of any clinical trial within the context of patients treated in routine practice,” said Dr. Baber.

The study had no commercial funding and the authors disclosed no conflicts of interest.

SOURCE: https://bit.ly/2vzbEGe

JAMA Intern Med 2017.

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