Aspirin Still Given Erroneously to Lower AF Stroke Risk

Researchers at the University of California, San Diego (UCSD, USA), the University of California, San Francisco (UCSF; USA), and other institutions conducted a study to examine patient and practice-level factors associated with prescription of aspirin and OAC in AF patients who are at intermediate to high stroke risk in real-world cardiology practices. The researchers identified two outpatient cohorts with AF and intermediate to high thromboembolic risk in the Practice Innovation and Clinical Excellence (PINNACLE) registry between 2008 and 2012.

The results showed that in the first cohort, consisting of 210,380 patients, 80,371 (38.2%) of the patients were treated with aspirin alone, while 130,009 (61.8%) were treated with warfarin or non-vitamin K antagonist OACs. In the second cohort, which included 294,642 patients, the results were similar, with 118,398 patients (40.2%) treated with aspirin alone, and 176,244 (59.8%) treated with warfarin or non-vitamin K antagonist OACs.

Analysis revealed that hypertension, dyslipidemia, coronary artery disease (CAD), prior myocardial infarction (MI), unstable and stable angina, recent coronary artery bypass graft (CABG), and peripheral arterial disease (PAD) were associated with prescription of aspirin alone. Male sex, higher body mass index (BMI), prior stroke/transient ischemic attack, prior systemic embolism, and congestive heart failure (CHF) were associated with more frequent prescription of OAC. The study was published in the June 2016 issue of the Journal of the American College of Cardiology.

“These data indicate a gap in care, most prominent in patients with or at risk for coronary artery disease,” concluded lead author Jonathan Hsu, MD, of UCSD, and colleagues. “It should draw attention to a high rate of prescription of aspirin therapy in atrial fibrillation patients at risk for stroke, despite previous data that show aspirin to be inferior to oral anticoagulants in this population.”

“This variance from guidelines does not appear to be related to true contraindication to anticoagulation, but may reflect a lack of appreciation that aspirin administration places a patient at significant risk for bleeding, while offering virtually no protection from stroke,” commented Sanjay Deshpande, MD, of St. Mary's Hospital (Milwaukee, WI, USA), in an accompanying editorial. “Take two aspirin and call me in the morning' is not appropriate treatment for a patient with atrial fibrillation at risk for thrombo-embolism. The clot only thickens.”

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