Higher blood pressure targets for hypertension in older adults.

BACKGROUND

This is an update of the original Cochrane review, published in 2017. Eight out of 10 major antihypertensive trials in adults, 65 years of age or older, attempted to achieve a target systolic blood pressure (BP) of < 160 mmHg. Collectively, these trials demonstrated cardiovascular benefit for treatment, compared to no treatment, for older adults with BP > 160 mmHg. However, an even lower BP target of < 140 mmHg is commonly applied to all age groups. Yet the risk and benefit of antihypertensive therapy can be expected to vary across populations, and some observational evidence suggests that older adults who are frail might have better health outcomes with less aggressive BP lowering. Current clinical practice guidelines are inconsistent in target BP recommendations for older adults, with systolic BP targets ranging from < 130 mmHg to < 150 mmHg. The 2017 review did not find compelling evidence of a reduction in any of the primary outcomes, including all-cause mortality, stroke, or total serious cardiovascular adverse events, comparing a lower BP target to a higher BP target in older adults with hypertension. It is important to update this review to explore if new evidence exists to determine whether older adults might do just as well, better, or worse with less aggressive pharmacotherapy for hypertension.

OBJECTIVES

To assess the effects of a less aggressive blood pressure target (in the range of < 150 to 160/95 to 105 mmHg), compared to a conventional or more aggressive BP target (of < 140/90 mmHg or lower) in hypertensive adults, 65 years of age or older.

SEARCH METHODS

For this update, Cochrane Hypertension's Information Specialist searched the following databases for randomised controlled trials up to June 2024: Cochrane Hypertension Specialised Register, CENTRAL, MEDLINE Ovid, and Embase Ovid, and the US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov for ongoing trials. We also contacted authors of relevant papers requesting information on further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We included randomised trials of hypertensive older adults (≥ 65 years) that spanned at least one year, and reported the effect on mortality and morbidity of a higher or lower systolic or diastolic BP treatment target. Higher BP targets ranged from systolic BP < 150 to 160 mmHg or diastolic BP < 95 to 105 mmHg; lower BP targets were 140/90 mmHg or lower, measured in an ambulatory, home, or office setting.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and selected trials for inclusion, assessed risk of bias and certainty of the evidence, and extracted data. We combined data for dichotomous outcomes using the risk ratio (RR) with 95% confidence interval (CI). For continuous outcomes, we used mean difference (MD). Primary outcomes were all-cause mortality, stroke, institutionalisation, and serious cardio-renal vascular adverse events. Secondary outcomes included cardiovascular mortality, non-cardiovascular mortality, unplanned hospitalisation, each component of cardiovascular serious adverse events separately (including cerebrovascular disease, cardiac disease, vascular disease, and renal failure), total serious adverse events, total minor adverse events, withdrawals due to adverse effects, systolic BP achieved, and diastolic BP achieved.

MAIN RESULTS

With the addition of one new trial, we included four trials in this updated review (16,732 older adults with a mean age of 70.3 years). Of these, one trial used a combined systolic and diastolic BP target and compared a higher target of < 150/90 mmHg to a lower target of < 140/90 mmHg, and two trials utilised a purely systolic BP target, and compared a systolic BP < 150 mmHg (1 trial) and a systolic BP < 160 mmHg (1 trial), to a systolic BP < 140 mmHg. The fourth and newest trial also utilised a systolic BP target, but also introduced a lower limit for systolic BP. It compared systolic BP in the target range of 130 to 150 mmHg to a lower target range of 110 to 130 mmHg. The evidence shows that treatment to the lower BP target over two to four years may result in little to no difference in all-cause mortality (RR 1.14, 95% CI 0.95 to 1.37; 4 studies, 16,732 participants; low-certainty evidence), but the lower BP target does reduce stroke (RR 1.33, 95% CI 1.06 to 1.67; 4 studies, 16,732 participants; high-certainty evidence), and likely reduces total serious cardiovascular adverse events (RR 1.25, 95% CI 1.09 to 1.45; 4 studies, 16,732 participants; moderate-certainty evidence). Adverse effects were not available from all trials, but the lower BP target likely does not increase withdrawals due to adverse effects (RR 0.99, 95% CI 0.74 to 1.33; 3 studies, 16,008 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS: When comparing a higher BP target, in the range of < 150 to 160/95 to 105 mmHg, to a lower BP target of 140/90 or lower, over two to four years of follow-up, there is high-certainty evidence that the lower BP target reduces stroke, and moderate-certainty evidence that the lower BP target likely reduces serious cardiovascular events. The effect on all-cause mortality is unclear (low-certainty evidence), and the lower BP target likely does not increase withdrawals due to adverse effects (moderate-certainty evidence). Although additional research is warranted in those who are 80 years of age and older, and those who are frail (in whom risks and benefits may differ), conventional BP targets may be appropriate for the majority of older adults.