Thromboembolism and bleeding complications in anticoagulated patients with atrial fibrillation and native aortic or mitral valvular heart disease: a descriptive nationwide cohort study

Aims: To describe the risks of thromboembolism and major bleeding complications in anticoagulated patients with atrial fibrillation (AF) and native aortic or mitral valvular heart disease using data reflecting clinical practice.

Methods and results: Descriptive cohort study of anticoagulated patients with incident AF and native aortic or mitral valvular heart disease, identified in nationwide Danish registries from 2000 to 2018. A total of 10 043 patients were included, of which 5190 (51.7%) patients had aortic stenosis, 1788 (17.8%) patients had aortic regurgitation, 327 (3.3%) patients had mitral stenosis, and 2738 (27.3%) patients had mitral regurgitation. At 1 year after AF diagnosis, the risk of thromboembolism was 4.6% in patients with mitral stenosis taking a vitamin K antagonist (VKA), and 2.6% in patients with aortic stenosis taking a VKA or non-vitamin K antagonist oral anticoagulant (NOAC). For patients with aortic or mitral regurgitation, the risks of thromboembolism ranged between 1.5%-1.8% in both treatment groups. For the endpoint of major bleeding, the risk was ∼5.5% in patients with aortic stenosis or mitral stenosis treated with a VKA, and 3.3-4.0% in patients with aortic or mitral regurgitation. For patients treated with a NOAC, the risk of major bleeding was 3.7% in patients with aortic stenosis and ∼2.5% in patients with aortic or mitral regurgitation.

Conclusion: When using data reflecting contemporary clinical practice, our observations suggested that 1 year after a diagnosis of AF, anticoagulated patients with aortic or mitral valvular heart disease had dissimilar risk of thromboembolism and major bleeding complications. Specifically, patients with aortic stenosis or mitral stenosis were high-risk subgroups. This observation may guide clinicians regarding intensity of clinical follow-up.