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New anticoagulant pills reduce cardiovascular events and do not increase serious bleeding

Sardar P, Chatterjee S, Chaudhari S, et al. New oral anticoagulants in elderly adults: evidence from a meta-analysis of randomized trials. J Am Geriatr Soc. 2014;62:857-64.

Review questions

In people 75 years of age or older who have atrial fibrillation, venous thromboembolism, or who are critically ill, do new anticoagulant pills (blood thinners) prevent cardiovascular events? Do they have side effects, such as serious bleeding?


People with conditions such as atrial fibrillation or venous thromboembolism are at increased risk of developing blood clots, which can increase the risk of heart attacks or stroke.  Doctors may prescribe anticoagulant pills to reduce the formation of blood clots. Warfarin (Coumadin®) is the anticoagulant pill prescribed most often. It requires careful monitoring by doctors and can cause serious bleeding. Newer anticoagulant pills are available and may be more effective, safer and easier to take.

How the review was done

The researchers did a systematic review, searching for published studies up to March 2013. They found 10 randomized controlled trials with 25,031 people 75 years of age or older.

People in the trials had venous thromboembolism, pulmonary embolism, or atrial fibrillation, or were critically ill.

New anticoagulant pills included rivaroxaban (Xarelto®), apixaban (Eliquis®), and dabigatran (Pradaxa®).

New anticoagulant pills were compared with usual treatment (warfarin, low-molecular weight heparin, or aspirin) or placebo.

Outcomes were cardiovascular events (venous thromboembolism; death due to venous thromboembolism; or stroke or systemic embolism), and serious bleeding.

What the researchers found

Compared with usual treatment or placebo, new anticoagulant pills:

  • reduced venous thromboembolism or death due to venous thromboembolism by about 33 people out of 1000; and
  • reduced stroke or systemic embolism by about 15 people out of 1000.

New anticoagulant pills did not differ from usual care or placebo for bleeding events at up to 2 years.


In people over 75 years of age with atrial fibrillation, venous thromboembolism, or critical illness, new anticoagulant pills reduce cardiovascular events without increasing serious bleeding.

New anticoagulant pills vs usual treatment (warfarin, low-molecular weight heparin, or aspirin) or placebo

Outcomes at about 2 years

Number of trials

New anticoagulant pills

Usual treatment or placebo

Effect of new anticoagulant pills

Venous thromboembolism or death due to venous thromboembolism

6 trials



About 33 fewer people out of 1000 had the outcome

Stroke or systemic embolism

4 trials



About 15 fewer people out of 1000 had the outcome

Serious bleeding

8 trials



No effect*

*The difference was not statistically significant. This means that the difference could simply be due to chance rather than due to the different treatments.


A harmless, inactive, and simulated treatment.
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.
The body's network of blood vessels. It includes the arteries, veins, and capillaries that carry blood to and from the heart.

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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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