Stroke and myocardial infarction in patients with abdominal aortic aneurysms and new-onset atrial fibrillation.

Objective We investigated the association between new-onset atrial fibrillation (AF) and risk of stroke and myocardial infarction (MI) in patients with abdominal aortic aneurysmal (AAA) disease. Methods Observational crossover study using Danish nationwide data, including patients with AAA and incident AF between 1997 and 2018. We estimated the one-year risk of stroke and myocardial infarction and the within-individual odds ratios (OR) of ischemic events before and after an AF diagnosis, stratified by year of AF diagnosis (1997-2010 and 2011-2018), and supplemented with analyses on changes in use of antithrombotic therapy. Results 3035 AAA patients were included: 1040 diagnosed during 1997-2010, and 1995 during 2011-2018 (22.2% females, median age 78 years; median CHA2DS2-VASc score 4 (IQR: 3-5). One-year risk of ischemic events after AF was 5.9% (CI 95%; 4.6%-7.5%) and 4.5% (CI 95%; 3.7%-5.5%) for stroke and 5.4% (CI 95%; 4.2%-6.9%) and 4.0% (CI 95%; 3.2%-4.9%) for MI during 1997-2010 and 2011-2018, respectively. The OR of ischemic stroke before and after incident AF was 2.8 (CI 95%; 1.6-5.2) during 1997-2010; and 2.4 (CI 95%; 1.5-3.9) during 2011-2018, and 3.5 (CI 95%; 1.7-7.5) and 1.5 (CI 95%; 0.9-2.4) for MI. One-year proportion of prescription claims for oral anticoagulants after AF changed from 66.1% (1997-2010) to 82.6% (2011-2018), while antiplatelet prescription claims changed from 80.8% to 60.9%. Conclusion Cardiovascular prognosis has improved in patients with prevalent AAA disease and new-onset AF in concordance with optimization of antithrombotic therapy over time. A diagnosis of AF conferred residual risk of stroke and myocardial infarction.