Nearly half of all atrial fibrillation patients at the highest risk for stroke are not being prescribed blood thinners by their cardiologists, according to a new study by researchers at University of California, San Diego School of Medicine and University of California, San Francisco.
The study was published online 16 March 16 2016 in JAMA Cardiology.
The four-year study, which involved more than 400,000 participants, found that as stroke risk factor scores generally increased, cardiologists were more likely to prescribe blood thinners, but atrial fibrillation patients with the highest risk for stroke were not prescribed oral anticoagulants as frequently as guidelines suggested.
“Despite a well-known association of atrial fibrillation with stroke, we found a significant lack of oral anticoagulant prescribed to reduce blood clots in high-risk patients. This is a wake-up call,” says lead author Jonathan C Hsu, cardiologist and assistant clinical professor of medicine at UC San Diego School of Medicine, San Diego, USA. “As the number of stroke cases in atrial fibrillation patients increase annually in the USA, our findings draw attention to a treatment gap in a demographic who may need these therapies the most.”
In this study, researchers found just under half (48%) of atrial fibrillation patients at the highest risk for stroke were not prescribed treatment.
“Well-informed and well-intended cardiologists may struggle with a lack of data regarding optimising risks versus benefits in patients with indications for anti-platelet drugs for their coronary artery disease and additional anticoagulants for their atrial fibrillation,” says senior author Gregory Marcus, cardiologist and endowed professor in atrial fibrillation Research at UC San Francisco School of Medicine, San Francisco, USA.
“However, while studies specifically addressing those challenging cases are needed, it is clear that identifying barriers to anticoagulant prescription, whether they involve physician education or enhanced patient access, will be the key to rectifying the situation.”
The authors said there are likely multiple reasons behind the practice, including the perceived risk of prescribing blood thinners in sicker patients.
“Physicians may be avoiding additional therapy in certain patients taking antiplatelet medications because of the increased risk of bleeding associated with the oral anticoagulants,” says Hsu. “It may be thought of as too dangerous for these sicker patients, but we still know that in most of these patients the benefits of blood thinning to reduce the risk of stroke outweigh the risks of bleeding.”
This research was funded, in part, by the American College of Cardiology National Cardiovascular Data Registry.