The American Heart Association and the American College of Cardiology are no longer recommending the use of the blood-thinning drug warfarin for the treatment of atrial fibrillation.

On Monday, Jan. 28, a new guideline was issued to encourage doctors not to prescribe the drug except to a select subset of patients with atrial fibrillation. Instead, the guideline advises the use of novel oral anticoagulants (NOACs), which have been developed and approved by the U.S. Food and Drug Administration in the past decade.

NOACs Over Warfarin

Warfarin, better known by the brand name Coumadin, is still generally safe to use. The new guideline is still stressing the importance of anticoagulants for patients who suffer from atrial fibrillation.

However, experts want to encourage the use of novel oral anticoagulants such as dabigatran, rivaroxaban, apixaban, and edoxaban. Novel oral anticoagulants are better at preventing stroke and have fewer, more manageable side effects compared to warfarin.

"In 2014, we recommend the use of warfarin and NOACs, but we didn't prioritize one over the other," said Craig January, a cardiologist at University of Wisconsin and the lead author of the 2014 and 2019 guidelines. "We are now saying that in some patients, NOACs are better than warfarin."

Safer And Easier To Manage

Warfarin was first developed as a rat poison but since 1954, it has been used to reduce the risk of blood clotting. Although it is often referred to as a blood thinner, it does not actually thin the blood. The drug blocks the formation of vitamin K-dependent clotting factors, reducing the possibility of clotting.

Those who use the drug are regularly monitored via blood tests to avoid the risk of clotting or excessive bleeding. The frequency of blood tests rise as people age, some being required to get their blood drawn once a week.

The new forms of anticoagulants no longer require the same level of monitoring. Patients who take novel oral anticoagulants only have to get their kidney and liver function test once a year.

Because of the lack of research, however, patients who have mechanical heart valves and moderate to severe mitral stenosis are told to continue taking warfarin.

What Is Atrial Fibrillation?

In the United States, 2.7 to 6.1 million people have some form of atrial fibrillation, the most common type of heart arrhythmia. People who have the condition experience irregular beating of the upper chamber of the heart.

Symptoms of atrial fibrillation include heart palpitations, lightheadedness, extreme fatigue, shortness of breath, and chest pain. The condition is most common in people 65 years old and above.