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Many AFib patients at highest risk of stroke not receiving recommended oral anticoagulant therapy

The JAMA Network Journals

In a study published online by JAMA Cardiology, Jonathan C. Hsu, M.D., M.A.S., of the University of California, San Diego, and colleagues examined the extent to which prescription of an oral anticoagulant in U.S. cardiology practices increases as the number of stroke risk factors increases for patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, with an estimated 1 in 4 lifetime risk in those older than 40 years and a projected increase in prevalence to approximately 5.6 million affected individuals by 2050 in the United States. Atrial fibrillation imparts stroke risk, and risk stratification schemes that include the CHADS2 score and, more recently, the CHA2DS2-VASc score have been developed to estimate the risk of thromboembolism (blood clot) in patients with AF based on specific risk factors. The extent to which prescription of oral anticoagulants (OACs) increases as the risk of stroke increases is not well known.

This study included 429,417 outpatients with AF enrolled in the American College of Cardiology National Cardiovascular Data Registry's PINNACLE Registry between January 2008 and December 2012. As a measure of stroke risk, the researchers calculated the CHADS2 score and the CHA2DS2-VASc score for all patients, and examined the association between increased stroke risk score and prescription of an OAC.

Prescribed treatment consisted of an OAC (45 percent of patients), aspirin only (26 percent), aspirin plus a thienopyridine (5.5 percent), or no antithrombotic therapy (24 percent). Each 1-point increase in risk score was associated with increased odds of OAC prescription compared with aspirin-only prescription. However, a plateau of OAC prescription was observed, with less than half of high-risk patients receiving an OAC prescription.

"These findings draw attention to important gaps in appropriate treatment of patients with AF at the highest risk of stroke and highlight opportunities to understand the reasons behind these gaps and insights to improve them," the authors write.


(JAMA Cardiology. Published online March 16, 2016; doi:10.1001/jamacardio.2015.0374. Available pre-embargo to the media at

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Note: An accompanying commentary, "Preventing Stroke in Patients With Atrial Fibrillation," by Jonathan P. Piccini Sr., M.D., M.H.S., of Duke University Medical Center, Durham, N.C., and Gregg C. Fonarow, M.D., of the University of California, Los Angeles, and Associate Editor, JAMA Cardiology, is available pre-embargo at the For The Media website.

Related Content From JAMA Cardiology: Incidence and Determinants of Traumatic Intracranial Bleeding Among Older Veterans Receiving Warfarin for Atrial Fibrillation

Media Advisory: To contact Jonathan C. Hsu, M.D., M.A.S., call Michelle Brubaker at 619-543-6163 or email

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