Stroke Risk Factors Despite Anticoagulation in Patients with Atrial Fibrillation

Using data from the GLORIA-AF registry, researchers evaluated the incidence and risk factors for residual adverse events in patients with atrial fibrillation. Lead author Wern Yew Ding and colleagues identified several predictive variables for ischemic stroke and ultimately judged that, despite use of anticoagulation therapy, patients with atrial fibrillation remain at high risk for complications.

The study, published in the Journal of the American Heart Association, analyzed 22,410 anticoagulated patients (median age, 65 years; 44.8% female) with newly diagnosed atrial fibrillation and an increased risk of stroke. Incidence of ischemic stroke was the primary outcome, while secondary endpoints included all-cause and cardiovascular mortality and myocardial infarction.

Atrial Fibrillation Adverse Events Despite Anticoagulation

Over a median follow-up of 3.0 years (interquartile range [IQR] 2.2-3.1), the researchers found that the incidence of ischemic stroke among the registry population was 0.60 per 100 patient-years (95% confidence interval [CI], 0.54-0.67). Additionally, the authors reported that the incidences of all-cause death, cardiovascular death, and myocardial infarction were 3.22 (95% CI, 3.08-3.37), 1.08 (95% CI, 1.00-1.16), and 0.59 (95% CI, 0.53-0.66), respectively, per 100 patient-years.

After multivariable Cox analysis, the researchers determined that age (hazard ratio [HR] 1.05; 95% CI, 1.03-1.07), diabetes (HR 1.42; 95% CI, 1.08-1.87), prior thromboembolism (HR 2.27; 95% CI, 1.73-2.98), and use of antiarrhythmic drugs (HR 0.66; 95% CI, 0.47-0.92) were independent predictors for residual ischemic stroke. The incidence of ischemic stroke was similar between patients treated with vitamin K antagonist (VKA) oral anticoagulants versus those treated with non-VKAs. However, there were differences in independent predictors between the groups, the investigators noted.

Ultimately, the authors suggested that “Further efforts among these patients should be directed at the management of modifiable risk factors that contribute to this risk.”

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