Abstract 11471: Peripheral Arterial Disease and Risk of Atrial Fibrillation and Stroke: The Multi-Ethnic Study of Atherosclerosis

Abstract

Introduction: Peripheral arterial disease (PAD) shares several risk factors with atrial fibrillation (AF) and persons with PAD have an increased risk of stroke. It is unclear if PAD is associated with an increased risk for AF and whether such an association explains the increased risk of stroke associated with PAD. Methods: We examined the association between PAD, as measured by the ankle-brachial index (ABI), and incident AF and incident stroke, separately, in 6,568 participants (mean age 62 ± 10; 53% women; 62% non-white) from the Multi-Ethnic Study of Atherosclerosis (MESA). ABI values <1.0 or >1.4 defined PAD in this analysis. Participants were free of baseline clinical cardiovascular disease and AF. AF was ascertained by review of hospital discharge records and from Medicare claims data until December 31, 2010. An independent adjudication committee ascertained stroke events. Cox regression was used to compute hazard ratios (HR) and 95% confidence intervals (95%CI) for the association between PAD and AF and stroke. Results: A total of 774 (12%) participants had baseline PAD. Over a median follow-up of 8.5 years, 301 (4.6%) participants developed AF and 140 (2.1%) developed stroke. In a model adjusted for socio-demographics, cardiovascular risk factors, and potential confounders, PAD was associated with an increased risk of AF (HR=1.5, 95%CI=1.1, 2.0). In a similar model, PAD was associated with incident stroke (HR=1.7, 95%CI=1.1, 2.5) and the magnitude of risk was not different after inclusion of AF as a time-dependent covariate (HR=1.7, 95%CI=1.1, 2.5). Similar results were obtained in subgroup analyses stratified by age, sex, and race/ethnicity. Conclusions: PAD is independently associated with an increased risk of AF and stroke in the MESA study. The relationship between PAD and stroke is not mediated by AF.