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In people 65 years or older, new anticoagulant pills reduce stroke, with fewer serious bleeds, compared with warfarin

Bai Y, Guo SD, Deng H, et al. Effectiveness and safety of oral anticoagulants in older patients with atrial fibrillation: a systematic review and meta-regression analysis. Age Ageing. 2017;8:1-9.

Review question

In older people with atrial fibrillation, how effective and safe is the blood thinner warfarin compared with no treatment or using other new anticoagulant pills (blood thinners)?


Atrial fibrillation is an abnormal heart rhythm that can cause small clots to form in the heart. These clots can travel to the brain causing a stroke, or they can travel to arteries in the legs, arms, or abdomen causing a systemic embolism. Doctors may prescribe anticoagulant pills (blood thinners) to reduce the formation of blood clots. Warfarin is the anticoagulant pill prescribed most often. It needs careful monitoring by doctors with frequent blood tests, and it can cause serious bleeding. Newer anticoagulant pills that don’t need frequent blood tests are also available, but not much research has been done on these pills in people older than 65 years of age.

How the review was done

The researchers did a systematic review, searching for studies published in English up to December 2016. They found 26 studies with people 65 years or older. 16 studies were randomized controlled trials, and 10 were observational studies.

People in the studies had atrial fibrillation.

Warfarin was compared with aspirin or no treatment in 10 of the studies.

Warfarin was compared with new anticoagulant pills in 16 of the studies. New anticoagulant pills included dabigatran, rivaroxaban, apixaban, and edoxaban.

Outcomes were stroke or systemic thromboembolism and serious bleeding.

What the researchers found

Warfarin reduced rates of stroke/systemic thromboembolism and did not affect serious bleeding compared with aspirin or no treatment.

The risk for stroke/systemic thromboembolism was lower with new anticoagulant pills compared with warfarin.

The risk for serious bleeding was lower with new anticoagulant pills compared with warfarin. However, there were differences in this result between the studies, which means this statement may not be true for everyone.

Not all people can take the new anticoagulant pills, and they are more expensive than warfarin.


In people 65 years of age and older with atrial fibrillation, warfarin is better than no treatment for reducing strokes/systemic thromboembolism, but the new anticoagulant pills are better than warfarin at reducing these events and cause fewer serious bleeds.

Warfarin vs no treatment or new anticoagulants in people 65 years and older who have atrial fibrillation


Number of studies

Comparison groups

Effect of warfarin at 4 months to 5 years

Stroke/systemic thromboembolism

8 studies

Warfarin vs no treatment*

Warfarin reduced stroke/systemic thromboembolism

Serious bleeding

7 studies

Warfarin vs no treatment*

No differences between groups

Stroke/systemic thromboembolism

4 randomized controlled trials

Warfarin vs new anticoagulants

New anticoagulants reduced strokes/systemic thromboembolism

Serious bleeding

4 randomized controlled trials

Warfarin vs new anticoagulants

New anticoagulants reduced serious bleeding

*No-treatment groups could include aspirin or no treatment.


Medications that suppress, delay, or prevent blood clots. Anticoagulants (also referred to as "blood thinners") are used to treat circulatory blockages.
Observational studies
Studies where the treatment that each person receives is beyond the control of the researcher.
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.

Related Web Resources

  • Atrial fibrillation

    Informed Health Online
    Atrial fibrillation is when the heart rate is abnormal, and usually too fast. Atrial fibrillation causes heart palpitations or feeling faint. There are different treatment options for atrial fibrillation; talk to your doctor about what would work best for you.
  • Atrial fibrillation - Preventing strokes

    Informed Health Online
    In the long term, atrial fibrillation can increase the risk of stroke. Some people might be at greater risk for a stroke, depending on what other risk factors they have. A doctor might prescribe anticoagulant medication to lower this risk.
  • Supraventricular tachycardia: Should I have catheter ablation?

    This patient decision aid helps people with heart rate problems with symptoms that bother them a lot and do not want to take medicine, or medicine has not worked decide on whether or not to have catheter ablation. It facilitates the process by comparing the benefits, risks, and side effects of both options.
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