Applied Evidence

Blood pressure targets: How low should you go (and for whom)?

Department of Pharmacy Practice, Texas Tech University Health Sciences Center (TTUHSC) School of Pharmacy (Drs. MacLaughlin and Young); Department of Family and Community Medicine (Drs. MacLaughlin, Slaton, and Young) and Department of Internal Medicine (Dr. MacLaughlin), TTUHSC School of Medicine, Amarillo, Tex; PinnacleHealth CardioVascular Institute, Wormleysburg, Pa (Dr. DePalma); Director of Regulatory and Professional Practice, American Academy of Physician Assistants, Alexandria, Va (Dr. DePalma)
Eric.MacLaughlin@ttuhsc.edu

Drs. MacLaughlin and DePalma were members of the Guideline Writing Committee for the 2017 American College of Cardiology/American Heart Association Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. This manuscript does not reflect the views or opinions of the Guideline Writing Committee.

Drs. Slaton and Young reported no potential conflict of interest relevant to this article.


 

References

Meta-analyses that have been conducted since SPRINT, and that have incorporated SPRINT data, also support lower BP goals. In the systematic review performed for the 2017 ACC/AHA guideline, an SBP <130 mm Hg compared to a higher BP target was associated with a reduced risk of major CV events, stroke, MI, and heart failure, although not all-cause mortality.8 These findings were largely consistent with other recent meta-analyses.12-15 For example, Bundy et al15 reported significant CV benefit with more vs less intensive BP lowering, whether or not the data from SPRINT were included, with the greatest reduction in risk seen in the groups with highest baseline BP.

It is important to consider a patient’s baseline level of risk when evaluating the absolute benefit of lower BP targets on CV outcomes. For patients with higher CV risk, the absolute benefit of treatment is greater.12-14 These findings support the 2017 ACC/AHA guideline, which recommends initiating drug therapy, in addition to lifestyle modification, in adults with hypertension and high ASCVD risk when the average BP is >130/80 mm Hg, with a goal of <130/80 mm Hg. TABLE 312-15,17-22 summarizes recent systematic reviews and meta-analyses conducted since the publication of JNC 8 that assess the association between intensity of BP lowering and adverse CV and related outcomes.

How low to go with BP? A look at recent systematic reviews and meta-analyses
How low to go with BP? A look at recent systematic reviews and meta-analyses

Treating patients with low CV risk

The evidence supporting a lower BP goal in patients with low CV risk is less than for patients at elevated risk. There are no large RCTs for this group that have assessed whether an intensive BP lowering strategy decreases CV outcomes more than a standard BP strategy (eg, <140/90 mm Hg). It is likely that absolute benefit is much smaller than for patients with, or at high risk for, ASCVD.

However, epidemiologic observational studies have indicated a significant log-linear increase in CV mortality starting at an SBP of 115 mm Hg.23 A 20-mm Hg increase in SBP above 115 mm Hg is associated with an approximate doubling of stroke and ischemic heart disease mortality risk.23 Decades worth of exposure to “elevated” BP levels would likely result in significant vascular damage, and attenuation of this process would likely be beneficial.24,25 An RCT specifically designed to test this hypothesis, however, would not be pragmatic considering the substantial number of patient-years that would be required.

Due to insufficient data documenting the value of antihypertensive drug therapy for primary prevention in adults with “elevated” BP and stage 1 hypertension at low risk for CVD, the 2017 ACC/AHA guideline recommends that drug therapy be initiated for all adults only when their BP average is ≥140/90 mm Hg.1 In contrast, for patients needing secondary prevention and for those with elevated CVD risk, the guideline recommends medication in addition to lifestyle modifications once the average BP is ≥130/80 mm Hg. The recommendation to withhold drug therapy until the BP is ≥140/90 mm Hg in patients needing primary prevention is supported by a new meta-analysis of 74 trials with 306,273 participants that aimed to assess the association between BP-lowering treatment and death and CVD at various BP levels.17 In this analysis, pharmacologic treatment was associated with a reduced risk of all-cause mortality, major CVD events, and coronary heart disease if the SBP was ≥140 mm Hg.

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