Abstract 19542: Relationship Between Ankle-Brachial Index Definitions and Coronary Artery Calcification: The Dallas Heart Study
Introduction: An ankle-brachial index (ABI) is used to screen patients for peripheral arterial disease (PAD), traditionally using the higher of the two foot pressures (dorsalis pedis and posterior tibial) for the standard definition. However, an ABI based on the lower of the two foot pressures (modified ABI) may be more predictive of worse cardiovascular (CV) outcomes. We sought to assess the relationship between the two different ABI definitions and coronary artery calcification (CAC) in the Dallas Heart Study (DHS).
Methods: DHS is a multi-ethnic probability-based population sample of subjects aged 30-65 years. CAC was assessed by MDCT and log-transformed for the analysis. Tobit linear regression was used to compare CAC distribution between the two ABI definitions.
Results: A total of 2,275 subjects with ABI and CAC were included (mean age 50.1 years, tobacco use 22%; 10-year Framingham score 3.1%). The prevalence of PAD (ABI ≤ 0.9) and was 7.5% and 24.8% by the standard and modified definitions, respectively; the prevalence of non-compressible disease (NCD; ABI > 1.4) was 6% and 2%. Median CAC scores for PAD were 13.4 and 0.0 (standard and modified ABI), and for NCD were 0.6 and 9.3. Using both definitions of ABI, PAD and NCD were significantly associated with higher CAC on univariate analysis (p=<0.05, each). No specific variations were noted by sex, race or diabetes status. After adjusting for traditional CHD risk factors, PAD by standard ABI was significantly associated with CAC (p=0.003) but not NCD (p=0.21). Neither PAD nor NCD defined by a modified ABI were associated with CAC on multivariate analysis (p=0.67 and p=0.08 respectively).
Conclusions: The presence of PAD on standard ABI measurements is associated with higher CAC levels, independent of traditional CV risk factors. However, a modified ABI definition incorporating the lower of two foot pressures was not independently associated with CAC.
- Peripheral artery disease (PAD)
- Peripheral vasculature
- Coronary artery calcification (CAC)
- Risk factors
Author Disclosures: T.P. Koshy: None. A. Khera: None. C. Ayers: None. C. Timaran: None. D.J. Kumbhani: None.
- © 2016 by American Heart Association, Inc.