Aspirin Often Wrongly Prescribed for Atrial Fibrillation

More than one-third of U.S. patients with the abnormal heartbeat atrial fibrillation (AF) who need a blood thinner to prevent strokes aren’t getting one, researchers say.

About 40% of AF patients deemed at moderate to severe risk of stroke because of age or other conditions are prescribed aspirin alone rather than recommended blood thinners such as Xarelto or warfarin, according to a new study.

“Despite clear guideline recommendations that patients at risk for stroke that have atrial fibrillation should be given blood thinners, many of these patients are not prescribed these potentially lifesaving medications,” said lead researcher Dr. Jonathan Hsu. He is an assistant professor of medicine, cardiology and cardiac electrophysiology at the University of California, San Diego.

In atrial fibrillation, the upper chambers of the heart beat rapidly and not in sync. The consequence of this irregular heart beat is that blood clots can form and travel to the brain, causing a stroke. Blood thinners are used to help prevent clots.

This study – based on patients from 123 cardiology practices in the United States – highlights inappropriate prescribing practices, Hsu said. His team used an American College of Cardiology registry to review medical records of more than 210,000 at-risk AF patients. They also conducted a secondary analysis of nearly 300,000 patients considered at-risk based on an updated guideline.

In both of these high-risk groups, roughly 40% were treated with aspirin and about 60% were prescribed a blood thinner, the investigators found.

Hsu suggested that some doctors may be unaware of current guidelines. Also, he said some patients may not want to take blood thinners – perhaps because of the risk for bleeding – or are unaware of their higher odds for stroke.

According to the latest guidelines, patients with atrial fibrillation who are 65 or older and those with at least one other condition – such as congestive heart failure, high blood pressure, diabetes or a prior stoke – should take a blood thinner. These factors are used by doctors to help assess stroke risk, Hsu said.