The risks associated with blood thinners may outweigh the benefits in younger atrial fibrillation (AFib) patients at low risk of stroke, according to a study published in the Journal of the American College of Cardiology.
Generally speaking, nearly all patients with atrial fibrillation—the most common type of abnormal heart rhythm—can benefit from blood thinners. Atrial fibrillation greatly increases risk of stroke. Blood thinners, which prevent blood clots, can greatly reduce that risk. However, blood thinners aren’t appropriate for all AFib patients.
According to guidelines from the American College of Cardiology, American Heart Association and Heart Rhythm Society, only patients at increased risk for stroke should take blood thinners, given the risk of complications associated with this type of drug. Physicians are able to determine stroke risk using the CHA2DS2-VASc score, which takes into account various cardiovascular risk factors, such as age and diabetes. Based on this score, patients with a risk score greater than 1 should take blood thinners, and it’s estimated that 85% of all patients with atrial fibrillation fall into this category.
However, researchers recently analyzed a national Swedish registry to determine whether all patients with a risk score of 1 should qualify for blood thinners. The registry included more than 140,000 patients with atrial fibrillation that never took blood thinners for their condition. Researchers compared the risk score among participants, tracking outcomes for up to five years, and found that stroke risk varied greatly among patients with a risk score of 1. Overall, stroke risk was lower than expected among patients with a risk score of 1, particularly for patients younger than 65 years of age.
Based on findings, authors believe that the risks associated with blood thinner use may outweigh the benefits in younger AFib patients at very low risk for stroke. However, few clinical trials have tested blood thinner use in low-risk AFib patients, and experts argue for further research on the issue. In general, blood thinners are beneficial for most AFib patients. But as experts emphasize, it’s important to prevent both over- and underuse of such treatment to provide the greatest net benefit to patients.