New Blood Thinner Prevents Strokes in Heart Patients

Aug. 10, 2011 -- The newly approved drug Xarelto appears to prevent strokes at least as well as the standard treatment warfarin in people who have a heart condition that puts them at high risk for blood clots, a study shows.

Xarelto was approved by the FDA in July to prevent dangerous blood clots in people having hip and knee replacement surgery. 

Next month, a panel of experts will consider whether the agency should also approve its use as a once-daily treatment for atrial fibrillation.

Atrial fibrillation causes the heart to pump in an irregular, uncoordinated way that may allow blood to pool and clot in its upper chambers. Those clots can travel to the brain, causing a stroke.

Patients with atrial fibrillation are commonly prescribed the blood-thinning drug warfarin, which is also sold under the brand names Coumadin and Jantoven.

"Warfarin, which we found in the '50s and '60s, is a very good drug in preventing stroke, but it's sometimes difficult to use," says study researcher Manesh R. Patel, MD, a cardiologist at Duke University.

Because it works by blocking vitamin K, foods that are high in that nutrient, like dark leafy greens, can make warfarin less effective. A host of other medications including some antibiotics and painkillers can interact with the drug, blocking or enhancing its effect.

Doctors typically require patients on warfarin to get monthly blood tests to make sure it's working properly and "not making the blood too thick or too thin, so to speak," Patel says.

Comparing Xarelto to Warfarin

A new study, published in The New England Journal of Medicine, tested Xarelto against warfarin in more than 14,000 patients with atrial fibrillation.

The patients in the study were deemed to be at moderate to high risk of stroke, either because they'd had a stroke before or because they had heart failure, high blood pressure, diabetes, or they were older than age 75.

Patients were randomly assigned to take either a daily dose of warfarin or Xarelto. To prevent people from knowing which treatment they were getting, both groups were also assigned to take a placebo pill.

Most patients were followed for about two years.

During that time, 269 people taking Xarelto and 306 people taking warfarin suffered strokes or had a blood clot that lodged somewhere else in the body, proving the drugs to be roughly similar.

"I think it's a reasonable alternative to warfarin. It's at least as good as warfarin," says Patel.

It doesn't require frequent trips back to the doctor, he tells WebMD, "so from a patient's perspective, it represents a potential alternative to the current standard."