P945Abnormalities in ankle-brachial indices are independently associated with new-onset atrial fibrillation

Introduction Lower extremity physiologic studies are an important non-invasive diagnostic tool in peripheral arterial disease (PAD). PAD and atrial fibrillation (AF) are associated with increased cardiovascular and all-cause mortality. Purpose To evaluate the association between PAD and new-onset AF and the risk of stroke. Methods We performed a study of all patients without AF undergoing ankle-brachial index (ABI) for any indication between January 1996 to June 2018. The ABI cut-off were as follows: abnormal ABI (0–0.99), normal ABI (1.00–1.39) and poor vessel compressibility (PC) (1.40+). Demographic, comorbidity, and outcome variables were extracted using the electronic medical record. Results Overall, 34,441 patients (mean age 66.8±14.3, 57.3% male, 88.2% white) were included in the study with a median follow-up of 7.2 years (interquartile range, 3.0–12.9 years). Multivariate Cox proportional hazard analysis showed increased risk of new-onset AF for male sex, older age, hypertension, coronary artery disease, cerebrovascular disease, chronic kidney disease stage III or greater, congestive heart failure, chronic obstructive pulmonary disease, and cancer (all p<0.0001). After adjustment, ABI results were significantly associated with new-onset AF, particularly poorly-compressible vessels (adjusted HR: 1.42 (1.30–1.55), p<0.0001) compared to abnormal ABI (adjusted HR: 1.12 (1.05–1.20), p=0.0012). Patients with atrial fibrillation were more likely to experience ischemic stroke (39.2% versus 16.1%, p<0.0001). Conclusion Abnormalities in ABI results, particularly poorly-compressible vessels, are independently associated with new-onset atrial fibrillation in a large ambulatory cohort. While the mechanism cannot be assessed, common inflammatory mechanisms and increased vascular stiffness may play an important role. Identification of AF in these at-risk patients may improve cardiovascular outcomes.