40% of patients with atrial fibrillation & stroke discharged with oral anticoagulants

Many patients with ischemic stroke and atrial fibrillation may not be receiving optimal care. A prospective study showed 60 percent of atrial fibrillation patients with recent acute ischemic stroke were either not discharged with oral anticoagulation or were discharged with a combination of oral anticoagulation and antiplatelet therapy.

Current guidelines from the American Heart Association and the American Stroke Association recommend oral anticoagulation alone to prevent secondary ischemic stroke in these patients.

The study, published online Nov. 6 in Stroke, found that physicians used a variety of prescribing practices to treat patients included in the Ontario Stroke Registry between 2003 through 2008. Patients were followed for a median of 3.3 years to determine outcomes.

Emer R. McGrath, MB, PhD, from Massachusetts General Hospital in Boston, and colleagues noted that 8 percent of patients were not prescribed antithrombotics at discharge. Of those who were, 21.6 percent were prescribed solely antiplatelet therapy, 39.3 percent oral anticoagulants only and 31.1 percent a combination of oral anticoagulants and antiplatelet therapy.

The research team found that lack of antithrombotic therapy increased risks of death or admission for recurrent stroke, MI or major bleeding by about half, compared to oral anticoagulation alone (hazard ratio [HR] 1.51 vs. 1, respectively). Antiplatelet therapy alone increased risk of the combined endpoint by almost a third (HR 1.31). A combination of oral anticoagulant and antiplatelet therapies reduced risk over recommended therapy marginally (HR 0.91). This relationship with treatment and outcomes remained among patients with severe stroke or coronary heart disease, with the exception of antiplatelet therapy and coronary heart disease, where only a slight increase in risk existed over oral anticoagulant therapy (HR 1.09).

Similar risks were seen for death as an endpoint. Both a lack of antithrombotic therapy and use of antiplatelet therapy alone had an increased risk of death over time (HR 1.57 vs. 1.42, respectively). Combination oral anticoagulant and antiplatelet therapy had a decreased risk compared to oral anticoagulant use alone (HR 0.94).

Risks were largely reversed when looking at admission for major bleeding and intracranial hemorrhage. Compared with oral anticoagulant alone, patients who were discharged without antithrombotic therapy or were discharged with antiplatelet therapy alone had less risk for major bleeding, while patients with combination oral anticoagulant and antiplatelet therapy had increased risks (HR 1 vs. 0.51 vs. 0.79 vs. 1.3, respectively).

McGrath et al wrote discussions needed to occur to improve care in all patients, since to some degree clinicians may not entirely grasp the full benefit of providing oral anticoagulation to patients with atrial fibrillation and stroke. In addition, based on the findings on combined therapy, they suggested future studies determine whether this high-risk group and those patients with severe stroke would indeed benefit with combination therapy over oral anticoagulants alone.