Evidence Summary

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After drug-coated stents are placed in heart arteries, use of 2 drugs for 1 year or less reduces deaths compared with longer use

Palmerini T, Benedetto U, Bacchi-Reggiani L, et al. Mortality in patients treated with extended duration dual antiplatelet therapy after drug-eluting stent implantation: a pairwise and Bayesian network meta-analysis of randomised trials. Lancet. 2015; 385:2371-82

Review question

After people with coronary heart disease have drug-coated stents placed in the heart arteries, should 2 antiplatelet drugs be used together for a longer or shorter time?


In people with coronary heart disease, arteries in the heart become narrowed or blocked. Putting stents in the arteries can open them up, and coating the stents with drugs (drug-eluting stents) can help keep blockages from coming back. However, stents can cause blood clots, which can cause strokes and heart attacks. Antiplatelet drugs help prevent blood clots, but can also cause bleeding, in people who have stents in the heart. 2 antiplatelet drugs are often used together (dual antiplatelet therapy) to prevent blood clots. It hasn’t been clear whether dual antiplatelet therapy should be used for a shorter or longer time after people get stents.

How the review was done

The researchers did a systematic review, searching for studies published up to November 2014.

They found 10 randomized controlled trials, with 31,666 people (average age 62 to 68 years). In these trials, 63% to 81% of the people were men.

The key features of the trials were:

  • people had drug-eluting stents placed in heart arteries;
  • dual antiplatelet therapy was taken for a shorter time (3 months, 6 months, or 12 months) or a longer time (12 months or more) after stents were placed; and
  • dual antiplatelet therapy most often included aspirin combined with clopidogrel.

What the researchers found

Compared with dual antiplatelet therapy taken for 1 year or more, shorter use reduced deaths and bleeding but increased heart attacks and blood clots from the stent.


After drug-coated stents are placed in heart arteries, use of dual antiplatelet therapy for about 1 year or less reduces deaths and bleeding but increases heart attacks and blood clots in stents compared with longer use.

Shorter vs longer use of dual antiplatelet therapy after drug-coated stents were placed in heart arteries


Number of trials and people

Rate of events with shorter therapy

Rate of events with longer therapy

Absolute effect of shorter therapy

Death for any reason

10 trials (31,666 people)



About 3 fewer people out of 1000 died (from fewer than 1 to as many as 6 out of 1000)

Any bleeding

9 trials (26,621 people)



About 13 fewer people out of 1000 had any bleeding (from as few as 10 to as many as 15 out of 1000)

Major bleeding

10 trials (31,666 people)



About 6 fewer people out of 1000 had major bleeding (from as few as 4 to as many as 7 out of 1000)

Heart attack

10 trials (31,666 people)



About 5 more people out of 1000 had a heart attack (from as few as 1 to as many as 10 out of 1000)


10 trials (31,666 people)



No difference in effect*

Blood clots from the stent

9 trials (26,621 people)



About 3 more people out of 1000 had a blood clot (from fewer than 1 to as many as 7 out of 1000)

*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.


Coronary heart disease
Also known as coronary artery disease (CAD), is a narrowing of the blood vessels (coronary arteries) that supply oxygen and blood to the heart.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Small mesh tubes.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

Related Web Resources

  • Coronary artery disease risk screening

    Health Link B.C.
    Men over 40 and women past menopause or over 50 should get screened for coronary artery disease (CAD) every 1 to 3 years. Your risk is higher if you have diabetes, high blood pressure, abdominal obesity, kidney disease, family history of CAD or if you smoke.
  • High cholesterol: Does reducing the amount of fat in your diet help?

    Informed Health Online
    Eat less saturated fats in your diet to help prevent heart disease. Eat less meat, butter, cheese and cream to improve your health long-term.
  • Statins: Should I Take Them to Prevent a Heart Attack or Stroke?

    This patient decision aid helps people considering taking medicines called statins to lower their risk of heart attack and stroke by comparing the benefits, risks, and side effects of both options. It also includes alternative treatment options to taking statins such as trying to lower risk with lifestyle changes.
DISCLAIMER These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (

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