Updated US guidelines suggest an increase by 19% in AF patients recommended for oral anticoagulation


An assessment of the 2014 American Heart Association (AHA), American College of Cardiology (ACC) and Heart Rhythm Society (HRS) guidelines concerning oral anticoagulation in atrial fibrillation indicates that two-thirds of patients who were not previously recommended for oral anticoagulation therapy are now recommended.

Emily O’Brien (The Duke Clinical Research Institute, Durham, USA), lead author of the study, recently published in JAMA-Internal Medicine, says: “The full adoption of the guidelines could reclassify nearly one million people with atrial fibrillation who previously were not recommended for treatment with blood thinners. What we do not know yet is the extent to which doctors in community practice will incorporate the guidelines into their clinical routines, and what that will mean for the long-term outcomes for those patients. That will be the next step for our study.”

Using ORBIT-AF (Outcomes registry for better informed treatment of atrial fibrillation) data, O’Brien et al compared the proportion of atrial fibrillation patients recommended for oral anticoagulation under the older 2011 guidelines and the new 2014 guidelines. The research concludes that the new guidelines could reclassify 988,500 patients presently excluded from oral anticoagulation therapy.

Prior to the new guidelines, oral anticoagulation was recommended for 71.8% of atrial fibrillation patients. By using the CHA2DS2-VASc refined stroke risk score, the new guidelines identify an additional 19% of atrial fibrillation patients who are now recommended for treatment with oral anticoagulation therapy. The researchers explain that the increase in patients with atrial fibrillation who were recommended for oral anticoagulation is due to “adoption of the CHA2DS2-VASc score, which was created to better identify patients with atrial fibrillation with truly low risk of stroke by incorporating information on female sex, younger age, and vascular disease.”

O’Brien et al compared changes in recommendations according to age and sex and found that for patients younger than 65 years the recommendation for oral anticoagulation increased from 43.1% to 60.6%. For patients 65 years or older the increment was from 79.1% to 98.5% and among women from 76.7% to 97.7%.

Oral anticoagulation can protect patients against a blood clot or stroke, but might also put patients at some increased risk for bleeding. However, for most patients, the benefits outweigh the bleeding risk, O’Brien comments.

Supported by Janssen Pharmaceuticals, the ORBIT-AF is a national, prospective, outpatient disease registry to identify real-world treatment patterns of atrial fibrillation in the USA. More than 10,000 patients at 176 sites in the US participate in
the registry.