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

Laser device placed on the heart identifies insufficient oxygenation better than other measures

September 20, 2017
A new device can assess in real time whether the body's tissues are receiving enough oxygen and, placed on the heart, can predict cardiac arrest in critically ill heart patients, report researchers at Boston Children's Hospital ...

Metabolism switch signals end for healing hearts

September 19, 2017
Researchers have identified the process that shuts down the human heart's ability to heal itself, and are now searching for a drug to reverse it.

Beta blockers not needed after heart attack if other medications taken

September 18, 2017
A new study from the University of North Carolina at Chapel Hill finds beta blockers are not needed after a heart attack if heart-attack survivors are taking ACE inhibitors and statins. The study is the first to challenge ...

Which single behavior best prevents high blood pressure?

September 15, 2017
(HealthDay)—You probably already know that certain healthy lifestyle behaviors can reduce your risk of developing high blood pressure, but is any one behavior more important than the others?

RESPECT trial shows closing a small hole in heart may protect against recurrent stroke

September 13, 2017
A device used to close a small hole in the heart may benefit certain stroke patients by providing an extra layer of protection for those facing years of ongoing stroke risk, according to the results of a large clinical trial ...

Study shows so-called 'healthy obesity' is harmful to cardiovascular health

September 11, 2017
Clinicians are being warned not to ignore the increased cardiovascular health risks of those who are classed as either 'healthy obese' or deemed to be 'normal weight' but have metabolic abnormalities such as diabetes.

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.