Abstract 18601: Risk of Arterial and Venous Thromboembolism in Patients With Atrial Fibrillation or Flutter: A 10-Year Nationwide Cohort Study
Introduction: Atrial fibrillation and flutter (AFF) create an intra-atrial stasis with the potential to cause thrombus formation and subsequent arterial and venous embolization. AFF is an established risk factor for ischemic stroke, but the extent to which AFF increases the risk of other thromboembolic events remains less clear.
Methods: During 2004-2013, we conducted a nationwide population-based cohort study using Danish medical registries. We identified all patients with a first-time AFF diagnosis and sampled a sex-, age-, and calendar year-matched general population comparison cohort without AFF. We computed cumulative risks and adjusted incidence rate ratios (aIRRs) with 95% confidence intervals (CIs) for myocardial infarction (MI), peripheral embolism, ischemic stroke, hemorrhagic stroke, deep vein thrombosis, and pulmonary embolism.
Results: The study population consisted of 103,989 patients with AFF and 519,935 individuals without AFF from the general population. Ten-year cumulative risks in the AFF cohort were 3.5% for MI, 0.5% for peripheral embolism, 6.7% for ischemic stroke, 1.3% for hemorrhagic stroke, 1.0% for deep vein thrombosis, and 1.3% for pulmonary embolism. During the first 30 days following AFF, aIRRs were markedly (4 to 16-fold) increased for all outcomes and similarly elevated for myocardial infarction (aIRR = 8.2, 95% CI: 6.9-9.7) and ischemic stroke (aIRR = 9.9, 95% CI: 8.5-11.5). Thereafter, aIRRs decreased gradually, reaching unity after 5 years for MI, deep vein thrombosis, and pulmonary embolism, but remained 1.5-2.5-fold increased for peripheral embolism, ischemic stroke, and hemorrhagic stroke.
Conclusions: In addition to being a risk factor for ischemic stroke, AFF was associated with increased risk of venous thromboembolism, MI, peripheral embolism, and hemorrhagic stroke, particularly during the first 30 days after diagnosis.
Author Disclosures: J. Sundbøll: None. E. Hováth-Puhó: None. K. Adelborg: None. A. Ording: None. M. Schmidt: None. H. Bøtker: None. H.T. Sørensen: None.
- © 2016 by American Heart Association, Inc.