Apixaban superior to warfarin across range of patient risk scores

October 1, 2012

A new anticoagulant called apixaban is superior to warfarin in preventing stroke with consistent effects across a wide range of stroke and bleeding risk in patients with atrial fibrillation, according to Duke University Medical Center researchers.

Their results, published online today in The Lancet, suggest that the current scoring systems for tailoring anticoagulation treatment to individual patients may be less relevant when using apixaban for patients with who have at least one risk factor for stroke.

"The benefits of apixaban are preserved regardless of the used and regardless of the patient risk category," said Renato Lopes, M.D., a Duke cardiologist and the lead author of the study. Importantly, apixaban was safer than warfarin in the overall population and tended to cause less intracranial in those patients whose risk scores defined them as being at the highest risk of bleeding.

"With new oral anticoagulants, such as apixaban, we might not need risk scores to guide for in patients with atrial fibrillation. This may simplify how physicians make decisions and also improve patient care," Lopes said.

Practice guidelines have allowed use of either with warfarin or with aspirin, which is less effective but has lower risk of bleeding, for patients with atrial fibrillation and one risk factor for stroke. Apixaban, with better prevention of stroke and lower risk of bleeding than warfarin, may remove aspirin as an attractive option for this group of patients.

Atrial fibrillation is a common that affects more than 2.6 million people in the United States. It occurs when the heart's electrical activity becomes disorganized, resulting in an with ineffective contraction of the upper chambers of the heart. The potential for blood clots to form, and one's risk for stroke, increases as a result.

Risk scores for bleeding and thromboembolism (blood clots) have been used to predict the risk of these events to guide use of warfarin, a vitamin K antagonist that is standard treatment to help prevent stroke and blood clots. Only about half of patients who could benefit from warfarin actually do because the drug has several limitations, including a requirement for regular monitoring and increased bleeding risk such as intracranial hemorrhage.

Apixaban is an oral direct factor Xa inhibitor that has already been shown to be safer and more effective than warfarin for patients with atrial fibrillation. Last year, Duke researchers presented the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial at the European Society of Cardiology. It showed apixaban resulted in an additional 21 percent relative reduction in stroke or systemic embolism when compared to warfarin, a 31 percent relative reduction in major bleeding, and an 11 percent relative reduction in overall mortality.

The analysis published in The Lancet used the ARISTOTLE data to assess safety and efficacy of apixaban versus warfarin in 18,201 patients based on the most popular risk assessment scores. CHADS2, CHA2DS2VASc, and HAS-BLED are used to estimate risk of stroke and bleeding in patients with atrial fibrillation and help guide warfarin treatment decisions.

"Risk stratification has been a key element in identifying patients at risk for stroke and bleeding and in helping to guide antithrombotic treatment for patients with atrial fibrillation," Lopes said. "However, most of patients at high risk for stroke are also at high risk for bleeding. This makes the treatment of these patients a challenge in clinical practice.

"Our study shows that irrespective of the risk of stroke or bleeding, apixaban is more effective and safer than warfarin across all patients with atrial fibrillation and at least one additional risk factor for ," Lopes said. "Thus, the current risk scores used in clinical practice for with atrial fibrillation may play less of a role in decision-making because we now have more efficacious and safer drugs."

Explore further: Apixaban superior to warfarin for preventing stroke, reducing bleeding and saving lives

Related Stories

Apixaban superior to warfarin for preventing stroke, reducing bleeding and saving lives

August 28, 2011
A large-scale trial finds that apixaban, a new anticoagulant drug, is superior to the standard drug warfarin for preventing stroke and systemic embolism in patients with atrial fibrillation. Moreover, apixaban results in ...

Chronic kidney disease increases stroke risk in A-fib

August 16, 2012
(HealthDay) -- Patients with atrial fibrillation who have chronic kidney disease are at higher risk of stroke or systemic thromboembolism and bleeding, according to a study published in the Aug. 16 issue of the New England ...

ARISTOTLE trial finds new drug may revolutionize the treatment of atrial fibrillation

October 26, 2011
New research has the potential to revolutionize the treatment of atrial fibrillation (AF), a condition affecting a quarter of a million Canadians which is expected to strike even more in the coming years, as the Canadian ...

Recommended for you

Half of people aged 40-54 have hardened arteries: study

December 11, 2017
Half of middle-aged people who are normal weight and don't smoke or have diabetes may have clogged arteries, researchers said Thursday, urging stronger measures to lower cholesterol.

Research suggests new pathways for hyperaldosteronism

December 7, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP), in collaboration with researchers at Eunice Kennedy Shriver National Institute of Child Health and Human Development, part of the ...

One-dose gene therapy produces clotting factor, safely stops bleeding in hemophilia B patients

December 6, 2017
A team of gene therapy researchers has reported positive results in a phase 1/2 clinical trial for the inherited bleeding disorder hemophilia B. A single intravenous infusion of a novel bioengineered gene therapy treatment ...

Clot-busting drugs not recommended for most patients with blood clots

December 6, 2017
Not all patients with blood clots in their legs - a condition known as deep vein thrombosis - need to receive powerful but risky clot-busting drugs, according to results of a large-scale, multicenter clinical trial.

Mitochondrial protein in cardiac muscle cells linked to heart failure, study finds

December 5, 2017
Reducing a protein found in the mitochondria of cardiac muscle cells initiates cardiac dysfunction and heart failure, a finding that could provide insight for new treatments for cardiovascular diseases, a study led by Georgia ...

Blood pressure declines 14 to 18 years before death

December 4, 2017
Blood pressure in the elderly gradually begins to decrease about 14 or so years before death, according to a new study published today in the JAMA Internal Medicine.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.