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Blood pressure–lowering drugs reduce cardiovascular events most in people with the highest initial risk

Sundstrom J, Arima H, Woodward M, et al. Blood pressure-lowering treatment based on cardiovascular risk: a meta-analysis of individual patient data. Lancet. 2014;384:591-8.

Review question

Do drugs that are used to treat high blood pressure reduce major cardiovascular events (e.g., stroke, heart attack, coronary heart disease) more in people who initially have a higher vs lower risk of those events?

Background

High blood pressure is usually defined as having a systolic blood pressure of 140 mm Hg or more or a diastolic blood pressure of 90 mm Hg or more. High blood pressure doesn’t always cause symptoms but can, over time, weaken or narrow blood vessels and cause strokes, heart attacks, or other heart problems.

Drugs that lower blood pressure can also reduce risk of cardiovascular events. They may work better in people who are initially at higher risk of cardiovascular events (e.g., older people, smokers, people with a family history of high blood pressure).

How the review was done

The researchers included data from 11 randomized controlled trials involving 51,917 people (average age 65 years, 45% women) in their analysis.

The key features of the trials were:

• drugs were given to lower blood pressure and included angiotensin-converting enzyme inhibitors (e.g., ramipril [Altace®], perindopril [Aceon®], trandolapril [Mavik®]), calcium channel blockers (e.g., amlodipine [Norvasc®, Amvaz®], felodipine [Plendil®]), and diuretics (e.g., indapamide [Lozol®]);
• most drugs were compared with placebo, although some trials compared higher-dose with lower-dose drugs; and
• outcome was major cardiovascular events (any of stroke, coronary heart disease [heart attack], heart failure [problems with the heart’s ability to pump blood], or other cardiovascular events).

What the researchers found

Compared with control (placebo or lower-dose drugs), blood pressure–lowering drugs:

• reduced major cardiovascular events regardless of initial risk level; and
• had a greater effect in people with the highest initial risk.

Conclusions

Blood pressure–lowering drugs reduce major cardiovascular events in people with different initial levels of risk. They provide the most benefit in people with the highest initial risk.

Blood pressure (BP)–lowering drugs vs control* in people with different levels of initial risk for major cardiovascular (CV) events†

*Most trials compared BP–lowering drugs with placebo; some compared higher-dose with lower-dose BP-lowering drugs.

†Major CV events include stroke, coronary heart disease (heart attack), heart failure (problems with the heart’s ability to pump blood), or other CV events.

‡The tendency for absolute benefit to increase along with initial risk was statistically significant.