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In people using blood pressure–lowering drugs, more-intensive therapy reduces cardiovascular events and strokes more than less-intensive therapy

Xie X, Atkins E, Lv J, et al. Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: updated systematic review and meta-analysis. Lancet. 2016;387:435-43.

Review question

In people who are prescribed drugs to lower blood pressure, does more-intensive therapy reduce the risk for major cardiovascular events (e.g., heart attack, heart failure) and stroke compared with less-intensive therapy?

Background

People with high blood pressure and some other conditions (e.g., diabetes, kidney disease) are more likely than many other people to have a major cardiovascular event. High blood pressure is usually defined as having a systolic blood pressure (SBP) of 140 mm Hg or more or a diastolic blood pressure (DBP) of 90 mm Hg or more.

Drugs that lower blood pressure can reduce risk for cardiovascular events. More-intensive drug therapy can reduce blood pressure more than less-intensive drug therapy. It may also be better for reducing cardiovascular events but could have more side effects.

How the review was done

The researchers did a systematic review, searching for studies that were published up to November 2015.

They found 18 randomized controlled trials with 44,604 adults (average age 41 to 77 years, 37% to 74% men) and 1 randomized controlled trial with 385 children (average age 12 years, 59% boys).

The key features of the studies were:

  • most people had high blood pressure; some had diabetes, chronic kidney disease, or more than one condition that increased risk for cardiovascular events;
  • drugs were used to reduce blood pressure to specific levels or by specific amounts;
  • more-intensive therapy was compared with less-intensive therapy;
  • more-intensive therapy aimed to reduce blood pressure more than less-intensive therapy; and
  • people were followed up for at least 6 months (3.8 years on average).

What the researchers found

Compared with less-intensive therapy, more-intensive blood pressure–lowering therapy:

  • reduced blood pressure (SBP by 6.8 mm Hg and DBP by 3.5 mm Hg);
  • reduced major cardiovascular events and stroke;
  • had similar rates of death, heart attack, heart failure, and end-stage kidney disease; and
  • had higher rates of severe low blood pressure, which can cause dizziness or fainting, although yearly event rates were low in both groups (0.1% in the lower-intensity group vs 0.3% in the higher-intensity group, with adverse events leading to discontinuation of treatment in 1% for each group).

Conclusion

In people who are prescribed drugs to lower blood pressure, more-intensive therapy reduces cardiovascular events and strokes more than less-intensive therapy.

More- vs less-intensive blood pressure–lowering therapy*

Outcomes

Number of trials and people

Rate of events with more-intensive therapy

Rate of events with less-intensive therapy

Absolute effect of more-intensive therapy at an average 3.8 years

Major CV events†

14 trials (43,483 people)

4.9%

5.7%

About 8 fewer people out of 1,000 had a major CV event (from as few as 3 to as many as 13)

Death from any cause

19 trials (44,989 people)

3.5%

3.8%

No difference in effect‡

Death because of CV events

13 trials (42,372 people)

1.6%

1.8%

No difference in effect‡

Death from any cause other than CV events

12 trials (41,993 people)

2.0%

2.0%

No difference in effect

Heart attack

13 trials (42,389 people)

1.7%

1.9%

No difference in effect‡

Heart failure

10 trials (33,306 people)

0.9%

1.1%

No difference in effect‡

Stroke

14 trials (43,483 people)

2.0%

2.6%

About 6 fewer people out of 1,000 had a stroke (from as few as 3 to as many as 9)

End-stage kidney disease§

8 trials (8,690 people)

5.8%

6.4%

No difference in effect‡

CV = cardiovascular.

*More-intensive drug therapy aimed to reduce blood pressure more than less-intensive drug therapy.

†This includes heart attack, heart failure, stroke, or death because of a CV event.

‡Although the rates for the 2 groups look a little different, the differences were not statistically significant. This means that the differences could simply be due to chance rather than due to the different treatments.

§End-stage kidney disease occurs when damage to kidneys is severe and cannot be reversed, usually requiring dialysis or kidney transplant.




Glossary

Diastolic
The lower number in a blood pressure reading. It is the pressure when the heart rests between beats.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.
Systolic
The higher number in a blood pressure reading. It is the pressure in the arteries when the heart beats.
Vascular
The body's network of blood vessels. It includes the arteries, veins, and capillaries that carry blood to and from the heart.

Related Web Resources

  • Blood pressure screening

    Health Link B.C.
    The Canadian Hypertension Education Program recommends that all adults get their blood pressure tested when they visit the doctor. If you are at risk for heart disease or a disease caused by high blood pressure, you should get your blood pressure checked more often.
  • The evidence on salt? The jury is still out

    Evidence-based Living
    Eating too much salt can make existing high blood pressure and heart disease worse. More unbiased and high quality research is needed to know whether salt intake is really a risk for healthy adults.
  • Salt and sodium: Heart risks and disease

    Harvard School of Public Health
    Eating too much salt can increase your blood pressure and lead to heart disease, especially if you are over 50, have high blood pressure or diabetes, or are African American. Try to eat less than a teaspoon of salt a day.
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