Reduced poststroke mortality in patients with stroke and atrial fibrillation treated with anticoagulants: results from a Danish quality-control registry of 22,179 patients with ischemic stroke

Abstract

Background and purpose: The preventive effect of anticoagulation in patients with stroke and atrial fibrillation (AF) is documented only in trials of minor stroke. Although anticoagulation reduced stroke recurrence, those trials did not demonstrate an influence of anticoagulation on survival.

Methods: A nationwide registry that was started in 2001 with the aim of registering all hospitalized stroke patients in Denmark now includes 24 791 patients. We studied the survival of patients with ischemic stroke and AF with respect to anticoagulation treatment. All underwent an evaluation for stroke severity (according to the Scandinavian Stroke Scale), computed tomography scan, and an evaluation for cardiovascular risk factors. Follow-up duration was 4 years (mean, 1.2 years).

Results: Of all patients, 22 179 (89.4%) experienced an ischemic stroke. In total, 3670 (16.5%) had AF, and 1909 had no contraindication to anticoagulation treatment. Anticoagulation treatment was initiated in 1149 of these patients (60.2%) but omitted in 760 (39.8%) despite no contraindication to such treatment. Of the patients so treated, 18.9% died during follow-up versus 45.2% without treatment. Patients who received treatment were younger (76.7+/-9.5 versus 80.7+/-9.0 years, P<0.0001) and had less severe strokes (Scandinavian Stroke Scale score, 42.0+/-15.0 versus 33.6+/-18.2, P<0.0001). A Cox proportional-hazards model was built to study the effect of anticoagulation on survival in patients without contraindications to treatment while controlling for stroke severity, sex, and cardiovascular risk factors. Patients without anticoagulation treatment were at greater risk of dying (hazard ratio=1.91, 95% CI=1.44 to 2.52) compared with patients who received anticoagulation treatment.

Conclusions: Our data suggest that anticoagulation treatment reduces poststroke mortality in patients with ischemic stroke and AF.