Are Oral Anticoagulants + Antiplatelets Overprescribed in A-fib Patients?

Data indicate the need to stop overprescribing AP agents in patients taking OAC
Data indicate the need to stop overprescribing AP agents in patients taking OAC

WASHINGTON, DC—Findings from the Stroke Prevention and Rhythm Interventions in Atrial Fibrillation (SPRINT-AF) registry point to "the need to avoid antiplatelet (AP) overprescription amongst oral anticoagulation (OAC)-treated patients in order to minimize bleeding," reported Milan Gupta, from Canadian Collaborative Research Network (CCRN), Brampton, Canada, at the ACC.17 Scientific Session.

Patients with atrial fibrillation (AF) taking oral anticoagulants for stroke prevention face a higher risk of bleeding when taking concomitant antiplatelet agents. "From a contemporary prospective registry, we sought to identify factors associated with OAC + AP vs. OAC use in a cohort of Canadian AF patients," explained Gupta.

A total of 2,499 patients with AF were enrolled in a prospective observational registry between November 2013 to March 2016. Gupta and coauthors of the study reported on data from the first 2,215 patients that were enrolled. In addition to reporting on demographics of patients treated with OAC + AP (primarily aspirin) vs. OAC alone, they performed a multivariable logistic regression with a backward selection algorithm to identify factors associated with OAC + AP vs. OAC use. 

Of the 1,795 (81%) patients treated with OAC, 288 (16%) of them were treated with a concomitant AP. Regression data showed patients treated with OAC + AP vs. OAC were alone had similar age (75.0±10.0 vs. 74.6±9.5 years; P=0.5). But patients in the OAC + AP group were more likely to be male, and have diabetes, heart failure, stroke/TIA, or vascular disease (eg, stable coronary artery disease, acute coronary syndrome, percutaneous coronary intervention, coronary artery bypass surgery, or peripheral vascular disease). 

There was also a ~2 to 3-fold greater burden of coronary artery disease among patients treated with OAC + AP vs. OAC alone. 

Data from the multivariable analysis indicated male sex (odds ratio 1.41, 95% CI: 1.05–1.89; P=0.02) and having vascular disease (OR 3.72, 95% CI: 2.85–4.84; P<0.01) were associated with a higher likelihood of concomitant OAC + AP use. Within the OAC + AP subgroup, 126 patients did not have a history of vascular disease. 

Findings from this modern AF registry showed that AP was co-prescribed in about 1/6 of OAC-treated patients. Vascular disease was highly associated with a higher chance of OAC + AP use, suggesting that the "perceived incremental gain in vascular protection from AP may outweigh the reality of bleeding when treatment decisions are made by physicians," added Gupta. 

There was also a "substantial proportion" of patients without known vascular disease who were receiving OAC + AP treatment, even without a clear indication for AP use. "These findings highlight an opportunity to reduce bleeding risk of OAC-treated AF patients by avoiding the use of AP when there is no compelling reason to do so," concluded Gupta. The 1-year follow-up of SPRINT-AF will address the clinical outcomes (stroke, TIA, bleeding) of this population.