Author + information
- Brian A. Ference,
- Nitin Mahajan,
- Stevo Julius,
- Wonsuk Yoo,
- Tochukwu Okwuosa,
- Luis Afonso,
- Phillip Levy,
- Kim Williams and
- John Flack
Persons with elevated blood pressure but without hypertension (prehypertension) are at increased risk of coronary heart disease (CHD). Whether lowering systolic blood pressure (SBP) among persons with prehypertension reduces the risk of CHD or slows the age-related rise in SBP is unknown. We evaluated the effect of naturally random allocation to lower SBP on these outcomes.
We constructed a genetic SBP score to evaluate the effect of 35 polymorphisms associated with lower SBP on the risk of CHD using data from the Welcome Trust Case-Control Consortium. We evaluated the effect of these polymorphisms on the age-related rate of rise in SBP by performing a meta-regression analysis involving up to 245,000 participants in 72 studies. We then used these effect estimates to model the results of a long-term natural randomized trial of lowering SBP among persons with prehypertension as compared to usual care.
Naturally random allocation to lifetime exposure to 10 mmHg lower SBP was associated with a 58% lower risk of CHD (OR: 0.42, 95 CI: 0.32-0.55; p = 8.2 × 10 −10). This represents a 3 to 4-fold greater risk reduction per mmHg lower SBP than observed in a meta-analysis of hypertension treatment trials (p = 1.4 × 10 −5) suggesting that the effect of elevated SBP on the risk of CHD is cumulative. Naturally random allocation to 10 mmHg lower SBP also reduced the rate of rise in SBP by 82%, from 5.5 mmHg/decade to 1.0 mmHg/decade (difference: 4.5 mmHg/decade, 95% CI: 1.2-8.3; p = 0.003). As compared to usual care (treatment to maintain SBP < 140 mmHg), lowering SBP by 10 mmHg (from 130 mmHg to 120 mmHg) among persons with prehypertension resulted in a rise in SBP of only 4 mmHg to 124 mmHg after 40 years of follow-up. By contrast, in the usual care arm, SBP would have risen to 152 mmHg if left untreated. At the end of the natural randomized trial, the two groups had a 16 mmHg difference in SBP (124 v. 140 mmHg), resulting in a 75% reduction in the risk of CHD (OR: 0.25, 95% CI: 0.16-0.38).
Lowering SBP beginning before the development of hypertension has the potential to largely eliminate the age-related rise in SBP, prevent the development of hypertension and dramatically reduce the risk of CHD.
North, Room 121
Sunday, March 10, 2013, 8:30 a.m.-8:45 a.m.
Session Title: Prevention: Blood Pressure – Hot Topics for 2013
Abstract Category: 25. Prevention: Hypertension
Presentation Number: 918-5
- 2013 American College of Cardiology Foundation