Intensive SBP reduction associated with lower CVD and all-cause mortality risk

Systolic Blood Pressure Reduction and Risk of Cardiovascular Disease and Mortality A Systematic Review and Network Meta-analysis

Literature - Bundy JD, Li C, Stuchlik P, et al. - JAMA Cardiol. 2017; published online ahead of print

Background

Due to the J-shaped association reported between achieved blood pressure (BP) and risk of coronary heart disease (CHD), cardiovascular disease (CVD) and all-cause mortality, there is uncertainty regarding the optimal treatment targets for hypertensive patients [1,2]. Similarly, the relevant clinical practice guidelines are inconsistent, when recommending BP targets [3-5].

In this network meta-analysis of 42 randomized clinical trials (published before December 15, 2015) including 144 220 patients, the association of different levels of systolic BP (SBP) reduction with the risk of major CVD, stroke, CHD, CVD mortality, and all-cause mortality was evaluated.

Main results

//Randomized groups with a mean achieved SBP of 120 to 124 mm Hg had the following HRs for major CVD: //

0.71 (95% CI: 0.60 - 0.83) compared with those with a mean achieved SBP of 130 to 134 mm Hg
0.58 (95% CI: 0.48 - 0.72) compared with those with a mean achieved SBP of 140 to 144 mmHg
0.46 (95%CI: 0.34 - 0.63) compared with those with a mean achieved SBP of 150 to 154 mmHg
0.36 (95% CI: 0.26 - 0.51) compared with those with a mean achieved SBP of 160 mmHg or more

Randomized groups with a mean achieved SBP of 120 to 124 mmHg had the following HRs for stroke:

0.69 (95% CI: 0.40 - 1.07) compared with those with a mean achieved SBP of 130 to 134 mm Hg
0.51 (95% CI: 0.26 - 0.87) compared with those with a mean achieved SBP of 140 to 144 mmHg
0.36 (95% CI: 0.17 - 0.68) compared with those with a mean achieved SBP of 150 to 154 mmHg
0.27 (95% CI: 0.12 - 0.51) compared with those with a mean achieved SBP of 160 mm Hg or more

A similar but weaker association between mean achieved SBP and CHD was observed.

Randomized groups with a mean achieved SBP of 120 to 124 mmHg had the following HRs for all-cause mortality:

0.73 (95% CI: 0.58 - 0.93) compared with those with a mean achieved SBP of 130 to 134 mmHg
0.59 (95% CI: 0.45 - 0.77 compared with those with a mean achieved SBP of 140 to 144 mmHg
0.51 (95% CI: 0.36 - 0.71) compared with those with a mean achieved SBP of 150 to 154 mmHg
0.47 (95% CI: 0.32 - 0.67) compared with those with a mean achieved SBP of 160 mmHg or more

Randomized groups with a mean achieved SBP of 120 to 124 mmHg had the following HRs for CVD mortality:

0.67 (95% CI: 0.40 - 1.22) compared with those with a mean achieved SBP of 130 to 134 mmHg
0.55 (95% CI: 0.30 - 1.07) compared with those with a mean achieved SBP of 140 to 144 mmHg
0.43 (95% CI: 0.22 - 0.93) compared with those with a mean achieved SBP of 150 to 154 mmHg
0.34 (95% CI: 0.17 - 0.76) compared with those with a mean achieved SBP of 160 mm Hg or more

In the sensitivity analysis, the lowest-risk group for stroke was the group with an SBP of 120 to 124 mmHg, and the lowest-risk group for CVD mortality was the group with an SBP of less than 120 mmHg.

In the main analyses, the lowest-risk group for stroke was the group with an SBP of less than 120 mmHg, and the lowest-risk group for CVD mortality was the group with an SBP of 120 to 124 mmHg.

Conclusion

In a network meta-analysis of randomized clinical trials, treating patients to reduce SBP below currently recommended targets was associated with a significantly reduced risk of CVD and all-cause mortality. These findings support a more intensive SBP control in patients with hypertension.

Editorial comment

In their editorial article [6] Yancy and Bonow comment that the meta-analysis by Bundy et al provide ‘’provocative evidence that lower is better and likely so in all cohorts with hypertension.’’ Based on the data they propose a 5-steps approach for the treatment of hypertension:

Confirm the diagnosis and evaluate secondary causes.
Determine the overall risk for CVD.
In those at higher CVD risk the target SBP goal should be less than 130 mmHg.
For those at lower risk the treatment goal should be less than 150 mmHg.
Keep in mind the risks of aggressive blood pressure lowering and polypharmacy.

The authors conclude: ‘’But for now, we should transition from the interrogative question of what treatment target is appropriate to the declarative statement that lower, preferably less than 130 mmHg, if safely attainable, is better.’’

References

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