Aspirin may be overprescribed in patients with AF

Although aspirin can cause potentially serious adverse effects, it is still overprescribed to prevent strokes in patients with atrial fibrillation (AF), according to a study published online Jan. 28 in The American Journal of Medicine.

Using data from the EURObservational Research Programme Atrial Fibrillation (EURO-AF) General Pilot survey, which included patients with diagnosed primary or secondary AF who presented to cardiologists in countries participating in the European Society of Cardiology, Gregory Y. H. Lip, MD, of the University of Birmingham Centre for Cardiovascular Sciences in Birmingham, U.K., and colleagues evaluated trends in antithrombotic therapy prescribing. They placed emphasis on risk factors that determined the use of oral anticoagulation or antiplatelet therapy. Their study included 3,119 patients.

Overall, the authors found that aspirin use was common, either on its own or with an oral anticoagulant. The main reason for using both drugs was coronary artery disease. 

Most hospitalized patients prescribed oral anticoagulants received a vitamin K antagonist (72.2 percent) and 7.7 percent received novel oral anticoagulants. These patients did not undergo cardioversion or catheter ablation. There were no significant differences between the two antithrombotic groups in terms of bleeding risk factors other than for patients with kidney disease—oral anticoagulation was less common in this subgroup.

Patients with a HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly) bleeding risk score of two or greater were more often prescribed antiplatelet therapy. Women used oral anticoagulants more often and patients with valvular heart disease, chronic heart failure, coronary artery disease and peripheral artery disease used them less often.

Based on the CHA₂DS₂-VAS_c (Cardiac failure of dysfunction, Hypertension, Age ≥ 75 [Doubled], Diabetes, Stroke [Doubled]-Vascular disease, Age 65-74, and Sex category [female]) stroke risk score, 95.6 percent of patients with a score of one or greater used antithrombotics, and 80.5 percent used oral anticoagulants. The majority of patients (83.7 percent) with a score of two or higher received antithrombotics and 70.9 percent used oral anticoagulants. Of the oral anticoagulant group, vitamin K antagonists were used in 64.1 percent and novel oral anticoagulants in 6.9 percent.

The authors also found that oral anticoagulants were not prescribed often enough in elderly patients and instead, aspirin alone was more common. Additionally, oral anticoagulation was less common in patients with paroxysmal AF compared with patients with permanent AF.

Lip said in a press release that some of the trends observed in the study were concerning. "Our study of antithrombotic prescribing by cardiologists reveals a positive trend of increasing oral anticoagulant use. But worrying misconceptions and practices remain regarding aspirin treatment of the elderly and paroxysmal AF."