Determining the Optimal Systolic Blood Pressure for Hypertensive Patients: A Network Meta-analysis

Background

There is clinical trial evidence that lowering systolic blood pressure (SBP) to < 120 mm Hg is beneficial, and this has influenced the latest American guideline on hypertension. We therefore used network meta-analysis to study the association between SBP and cardiovascular outcomes.

Methods

We searched for randomized controlled trials targeting different blood pressure levels that reported cardiovascular events. The mean achieved SBP in each trial was classified into 5 groups (110-119, 120-129, 130-139, 140-149, and 150-159 mm Hg). The primary variables of cardiovascular mortality, stroke, and myocardial infarction were assessed using frequentist and Bayesian approaches.

Results

Fourteen trials with altogether 44,015 patients were included. Stroke and major adverse cardiovascular events were reduced when lowering SBP to 120-129 mm Hg compared with 130-139 mm Hg (odds ratio OR] 0.83, 95% confidence interval CI] 0.69-0.99 and OR 0.84, 95% CI 0.73-0.96), 140-149 mm Hg (OR 0.73, 95% CI 0.55-0.97 and OR 0.74, 95% CI 0.60-0.90), and 150-159 mm Hg (OR 0.43, 95% CI 0.26-0.71 and OR 0.41, 95% CI 0.30-0.57), respectively. More intensive control to < 120 mm Hg further reduced stroke (OR 0.58, 95% CI 0.38-0.87; OR 0.51, 95% CI 0.32-0.81; and OR 0.30, 95% CI 0.16-0.56). In contrast, SBP ≥ 150 mm Hg increased myocardial infarction and cardiovascular mortality compared with 120-129 mm Hg (OR 1.73, 95% CI 1.06-2.82 and OR 2.18, 95% CI 1.32-3.59) and 130-139 mm Hg (OR 1.53, 95% CI 1.01-2.32 and OR 1.71, 95% CI 1.11-2.61). No significant relationship between SBP and all-cause mortality was found.

Conclusions

SBP < 130 mm Hg is associated with a lower risk of stroke and major adverse cardiovascular events. Further lowering to < 120 mm Hg can be considered to reduce stroke risk if the therapy is tolerated. Long-term SBP should not exceed 150 mm Hg because of the increased risk of myocardial infarction and cardiac deaths.