Abstract 12715: Aortic Arch Width Adds to Coronary Artery Calcium for Prediction of Incident Adverse Cardiovascular Disease Events: The Framingham Heart Study

Abstract

Introduction: Aortic arch width (AAW) is cross-sectionally associated with multiple cardiovascular disease (CVD) risk factors. We sought to determine whether AAW would add to standard Framingham risk factors (FRF) and coronary artery calcium (CAC) as a predictor of incident adverse CVD events. Methods: AAW, the distance between the centroids of the ascending and descending aorta at the level of main pulmonary artery bifurcation, was measured in 3026 Framingham Offspring and Third Generation cohort members who underwent computed tomography (CT) for CAC assessment over 2002-2005. Upper 90th percentile (P90) limits, based on sex, age and body surface area, were determined from a healthy referent group (no hypertension, diabetes, dyslipidemia, smoking; N=1471). Participants with prevalent CVD (N=119) or missing covariates (N=27) were excluded from further analysis, leaving 2880 who were dichotomized by AAW ≥P90 (high AAW) or <P90. Cox proportional hazards models were used to estimate hazard ratio (HR) of high AAW on time-to-CVD (composite of: CVD death; myocardial infarction, MI; unstable angina, USA; stroke; first admission for heart failure, HF) after adjustment for FRF (listed in Table) and log(CAC+1). The category-free net reclassification improvement (NRI) metric was used to assess the effect of adding AAW to the baseline FRF+CAC model. Results: Overall prevalence of high AAW was 19.2%. There were 135 incident CVD events (6 CVD death, 49 MI, 4 USA, 42 stroke, 34 HF) over median 8.9-y follow up. High AAW was independently predictive of CVD, HR=1.55, p=0.032, and improved prediction over FRF+CAC (Table) with NRI=0.31; 95%CI=0.15-0.48. Conclusions: AAW is commonly visualized on MRI or CT of the chest and is simple to measure. High AAW adds to traditional CVD risk factors and CAC for prediction of incident CVD events among community dwelling adults. These data suggest AAW has utility for CVD risk stratification; findings remain to be replicated in other cohorts.