Co-existence of vascular disease in different arterial beds: Peripheral artery disease and carotid artery stenosis--Data from Life Line Screening(®)

Abstract

Background: Atherosclerosis is a systemic vascular disorder, involving multiple arterial territories. This project sought to investigate the relationship between lower extremity peripheral artery disease (PAD) and carotid artery stenosis (CAS) in a large self-referred population.

Methods: Data from the ankle brachial index (ABI) and carotid duplex ultrasound were analyzed from 3.67 million US subjects in the Life Line Screening program between 2004 and 2008. PAD was defined by ABI<0.9 and CAS was defined by greater than 50% stenosis. Multivariate logistic regression analysis was used to estimate odds of CAS by PAD status and severity.

Results: Mean age of the population was 63.7 ± 10.6 years and 64% were women. The prevalence of PAD and CAS was 4.1% and 3.9%, respectively. Subjects with PAD had a higher prevalence of CAS than those without PAD (18.8% vs. 3.3%, P < 0.0001). In multivariate analysis, PAD was associated with greater odds of CAS (OR 3.28, 95% CI 3.22-3.34). Both symptomatic (OR 3.66, 95% CI 3.58-3.75) and asymptomatic PAD (OR 2.91, 95% CI 2.84-2.98) was associated with CAS. Increasing severity of PAD was associated with greater odds of CAS (OR 2.32, 3.61, 4.19, 5.14, and 7.59 for ABI categories 0.81-0.90, 0.71-0.80, 0.61-0.70, 0.41-0.60, ≤0.40, respectively).

Conclusion: Presence and severity of PAD was associated with prevalence of CAS in the large self-referred and self-paying Life Line cohort, regardless of lower extremity symptoms.

Keywords: Carotid artery stenosis; Peripheral artery disease.