Association of Peripheral Artery Disease With Incident Atrial Fibrillation: The ARIC (Atherosclerosis Risk in Communities) Study

Abstract

BackgroundAlthough peripheral artery disease as defined by ankle‐brachial index (ABI) is associated with incident atrial fibrillation (AF), questions remain about the risk of AF in borderline ABI (>0.90 to <1.0) or noncompressible arteries (>1.4). We evaluated the association of borderline ABI and ABI >1.4 in the ARIC (Atherosclerosis Risk in Communities) study, a population‐based prospective cohort study.Methods and ResultsWe included 14 794 participants (age, 54.2±5.8 years, 55% women, 26% blacks) with ABI measured at the baseline (1987–1989) and without AF. AF was identified from hospital records, death certificates, and ECGs. Using Cox proportional hazards, we evaluated the association between ABI and AF. During a median follow‐up of 23.3 years, there were 2288 AF cases. After adjustment for cardiovascular risk factors, hazard ratio (HR) (95% confidence interval) for AF among individuals with ABI <1.0 compared with ABI 1.0 to 1.4, was 1.13 (1.01–1.27). ABI >1.4 was not associated with increased AF risk. ABI ≤0.9 and borderline ABI were associated with a higher risk of AF compared with ABI 1.0 to 1.4. Demographics‐adjusted HRs (95% confidence interval) were 1.43 (1.17–1.75) and 1.32 (1.16–1.50), respectively. However, the associations of ABI ≤0.9 and borderline ABI with AF were attenuated after adjusting for cardiovascular risk factors (HR [95% confidence interval], 1.10 [0.90–1.34] and 1.14 [1.00–1.30]), respectively.ConclusionsPeripheral artery disease indicated by low ABI, including borderline ABI, is a weak risk factor for AF. ABI >1.4 is not associated with an increased AF risk. The relationship between peripheral artery disease and AF appears to be mostly explained by traditional atherosclerotic risk factors.

Association Between Peripheral Artery Disease and Incident Risk of Atrial Fibrillation: Strong Evidence Coming From Population‐Based Cohort Studies

“…Similar data were retrieved when the meta‐regression analysis was performed according to the ABI classes (data not shown). A cumulative cubic spline model was obtained, pooling together the spline curves from the 3 studies included in the analysis,6, 7, 8 confirming the inverse dose‐effect response between ABI and the risk of incident AF (Figure 1). The pooled cubic spline also confirmed that the risk is still present, despite being lower, in the borderline ABI class (Figure 1).…”

“…To reach our aim, we performed a meta‐analysis and meta‐regression of data coming from the 3 studies6, 7, 8 (Table), including a total of 26 505 subjects. Bayesian meta‐analyses under heterogeneity were conducted by means of hierarchical (log‐) gaussian models with informative priors, according to previously published articles 10.…”

“…After full adjustment for all the concomitant risk factors and cardiovascular comorbidities, despite being attenuated, the association remained significant, with 13% increase in relative risk compared with subjects with normal ABI (1.00-1.40). 8 Conversely, patients with ABI ≥1.40 did not have an increased risk of AF in both unadjusted and adjusted analyses. These results, although assessed on a larger cohort, substantially confirmed the previous data on the relationship between ABI and incident AF.…”

“…1 In this issue of the Journal of the American Heart Association (JAHA), Bekwelem and colleagues present an analysis derived from the ARIC (Atherosclerosis Risk in Communities) Study, about the association between PAD and risk of new-onset AF. 8 ARIC is a large, prospective, epidemiologic study conducted in 4 US communities, aimed to investigate causes and mechanisms of atherosclerosis, the variation and interaction between relevant risk factors and demographic variables, and the influence on long-term outcomes. 9 With 15 792 patients followed up for 20 years, the ARIC Study published >2000 articles and represents a robust study still providing relevant and reliable insights into the pathophysiological mechanisms of atherosclerosis and its clinical sequelae.…”

“…These results, although assessed on a larger cohort, substantially confirmed the previous data on the relationship between ABI and incident AF. 8 The article from Bekwelem and colleagues reported that borderline ABI (0.91-0.99) is significantly associated with incident AF after both age-sex-race adjustment (HR, 1.32; 95% CI, 1.16-1.50) and full adjustment (HR, 1.14; 95% CI, 1.00-1.30). 8 ≤0.90 remained associated with incident AF after age-sexrace adjustment (HR, 1.43; 95% CI, 1.17-1.75), full adjustment strongly attenuated the relationship (HR, 1.10; 95% CI, 0.90-1.34).…”