Intensive vs. Standard Ambulatory Blood Pressure Lowering to Lessen Functional Decline in the Elderly - INFINITY

Contribution To Literature:

The INFINITY trial failed to show that intensive ambulatory BP lowering was superior at improving mobility and cognitive function; however, it was associated with a reduction in subcortical white matter disease.

Description:

The goal of the trial was to evaluate intensive ambulatory systolic blood pressure (SBP) lowering compared with standard ambulatory SBP lowering among elderly patients with hypertension and evidence of subcortical white matter hyperintensity lesions.

Study Design

  • Randomized
  • Parallel
  • Blinded

Elderly patients with hypertension were randomized to intensive ambulatory SBP lowering (systolic ≤130 mm Hg; n = 99) versus standard ambulatory SBP lowering (systolic ≤145 mm Hg; n = 100).

  • Total number of enrollees: 199
  • Duration of follow-up: 3 years
  • Mean patient age: 80 years
  • Percentage female: 54%

Inclusion criteria:

  • Office SBP 150-170 mm Hg on ≥1 antihypertensive drug or >170 mm Hg on 0-1 antihypertensive drug
  • 24-hour ambulatory SBP ≥140 mm Hg
  • White matter hyperintensity on brain magnetic resonance imaging

Exclusion criteria:

  • Unstable cardiovascular or chronic neurologic condition

Other salient features/characteristics:

  • After a median period of 3-4 months, mean 24-hour SBP: 127.7 mm Hg in the intensive group compared with 144.0 mm Hg in the standard group

Principal Findings:

The co-primary outcome, percent change from baseline to end of study white matter hyperintensity, was 0.29 in the intensive group compared with 0.50 in the standard group (p = 0.03).

The co-primary outcome, change from baseline to end of study gait speed, was 0.40 in the intensive group compared with 0.42 in the standard group (p = 0.91).

Secondary outcomes:

  • Change from baseline to end of study symbol digit modalities test: -2 in the intensive group compared with -1 in the standard group (p = 0.29)
  • Nonfatal cardiovascular event: 4.1% in the intensive group versus 17% in the standard group (p < 0.01)

Interpretation:

Among elderly patients with hypertension, intensive lowering of ambulatory SBP reduced the development of subcortical white matter disease. However, intensive lowering of SBP was not associated with improvement in mobility or cognitive function. Intensive lowering of SBP was associated with a reduction in nonfatal cardiovascular events.

In the larger SPRINT trial, which randomized patients to target SBP <120 mm Hg versus <140 mm Hg, intensive blood pressure lowering was associated with a reduction in mild cognitive impairment (although no difference in the incidence of dementia). It is possible that 3 years was too short a follow-up period to detect improvements in mobility and cognitive function from intensive blood pressure lowering.

References:

White WB, Wakefield DB, Moscufo N, et al. Effects of Intensive Versus Standard Ambulatory Blood Pressure Control on Cerebrovascular Outcomes in Older People (INFINITY). Circulation 2019;Oct 14:[Epub ahead of print].

Presented by Dr. William B. White at the American College of Cardiology Annual Scientific Session (ACC 2019), New Orleans, LA, March 18, 2019.

Clinical Topics: Diabetes and Cardiometabolic Disease, Geriatric Cardiology, Noninvasive Imaging, Prevention, Vascular Medicine, Magnetic Resonance Imaging, Hypertension, Sleep Apnea

Keywords: ACC Annual Scientific Session, ACC19, Antihypertensive Agents, Blood Pressure, Blood Pressure Monitoring, Ambulatory, Cognition, Dementia, Vascular, Gait, Geriatrics, Hypertension, Magnetic Resonance Imaging, Metabolic Syndrome X, Mobility Limitation, Primary Prevention


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