The report is a product of the VA/HSR Evidence Synthesis Program.

Systematic Review: Benefits and Harms of Treating Blood Pressure in Older Adults

Hypertension is a very common chronic illness in the United States and among Veterans. Use of antihypertensive medications can lower the risk of cardiovascular disease, cerebrovascular disease, renal disease, and death. However, the most beneficial blood pressure targets for patients of specific age groups has been a topic of some debate, stemming from concerns that the ratio of benefit to harm of a given blood pressure level may vary with age. In 2014, the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure published new guidelines for the treatment of hypertension, as well as a new treatment goal for older individuals (over age 60) for systolic blood pressure (SBP) of <150 mm Hg rather than <140 mm Hg. The new goal for those over 60 years of age has been very controversial, and has been debated among experts with viewpoints supporting both higher and lower treatment goals.

Conducted by investigators with the VA Evidence-Based Synthesis Program (ESP) in Portland, Oregon, this systematic review examined the current literature in order to examine the benefits and harms of differing blood pressure targets among adults over age 60. ESP investigators reviewed the literature from inception through December 2015. After reviewing more than 10,600 titles and abstracts, they identified 21 randomized controlled trials (RCTs) and 3 cohort studies that fit their review criteria. Findings from this systematic review show:

• There was high-strength evidence that blood pressure treatment in patients over age 60 reduces mortality, stroke, and cardiovascular events. The greatest absolute effects are seen in studies of patients with higher baseline blood pressures (SBP ≥160 mm Hg) achieving moderate blood pressure control (<150/90 mm Hg). The number needed to treat (NNT) over 2-5 years to prevent one outcome was 61-89.
• Evidence from six treat-to-target trials suggests that lower treatment targets (<140/85 mm Hg) as compared to more moderate targets (<150/90 mm Hg) reduce the risk of stroke and cardiovascular events, but the absolute effects are smaller (NNT 106-286) and there is no significant effect on all-cause mortality.
• Moderate-strength evidence showed that more aggressive blood pressure control (SBP <140 mm Hg) in patients with prior stroke substantially reduced rates of recurrent stroke (NNT 33) and had a more modest effect on cardiovascular events (NNT 106).

Findings also indicate that lower treatment targets are associated with higher medication burden and an increased risk of short-term harms such as hypotension. On the other hand, evidence that there is not an increase in longer-term harms such as cognitive impairment, falls, and reduced quality of life, may provide some flexibility for providers attempting to weigh the risks and benefits of more antihypertensive therapy in crafting an individualized treatment plan. There was little data to assess the balance of risks and benefits of antihypertensive treatment among the frail elderly.

Future Research
There is a need for more research that examines how the severity of comorbidity and the presence of multiple comorbidities modify the effects of more intensive blood pressure treatment. Though there have been more recent trials that have included patients over age 80, there is a need for more research in this age group. Moreover, future studies should enroll patients who have not yet been represented in the evidence, including those with cognitive impairment and other causes of frailty. Finally, future reviews using individual patient-level data on medication use could clarify whether or not the findings in this report apply equally across anti-hypertensive drug classes.

A Cyberseminar session on this ESP Report will be held on Wednesday, October 5, 2016 from 2:00pm to 3:00pm (ET). To register, go to the HSR&D Cyberseminar web page.

Reference
Weiss J, Kerfoot A, Freeman M, Motu'apuaka M, Fu R, Low A, Paynter R, Kondo K, Kansagara D. Benefits and harms of treating blood pressure in older adults: a systematic review and meta-analysis. VA ESP Project #05-225; 2015.

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This report is a product of VA/HSR&D's Quality Enhancement Research Initiative's (QUERI) Evidence-Based Synthesis Program (ESP), which was established to provide timely and accurate synthesis of targeted healthcare topics of particular importance to VA managers and policymakers – and to disseminate these reports throughout VA.

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