Abstract 5205: Aortic Arch Calcification Detectable on Chest X-ray is a Strong Independent Predictor of Cardiovascular Events Beyond Traditional Risk Factors

Abstract

Background: Aortic stiffness resulting from calcification makes management of hemodynamic status more difficult. Some reports have previously shown that simple assessment of aortic calcification in aortic arch and abdominal aorta using plain radiography can predict cardiovascular (CV) events. However, these studies simply assessed whether aortic calcification detectable on X-ray was present or absent, without considering the grade of calcification. In this study, we evaluated the validity and usefulness of grading aortic arch calcification (AAC) to predict new CV events, and compared it to traditional atherosclerotic risk factors. Methods and Results: This study enrolled 239 asymptomatic outpatients (mean age 61±14 years) without previous CV events. We divided the extent of AAC into four grades (from 0 to 3) by reviewing a postero-anterior plain chest X-ray. AAC grade was 0, 1, 2, and 3 in 46%, 22%, 29%, and 4% of the subjects, respectively. AAC grade was positively related to age, prevalence of diabetes and chronic kidney disease (CKD), and showed a significant association with clustering of traditional risk factors. In addition, impairment of endothelial function, as determined by flow-mediated dilation (FMD), was also associated with increasing AAC grade. Thirty two new CV events in total occurred during a mean follow-up period of 40±19 months. With multivariate adjustment, Kaplan-Meier analysis showed that the new incidence of CV events was significantly higher in patients with high AAC grade (grades 2 and 3) than in those with grade 0 or 1 (p<0.01, log-rank test). Multivariate Cox-proportional hazards analysis showed that the predictive value of AAC grade for CV events was significantly stronger (hazard ratio, 1.8; 95% confidence interval, 1.2–2.8; p <0.01) than that of FMD, HbA1c, and estimated GFR. In addition, predictive usefulness was found even in patients without CKD. Conclusion: AAC detectable on chest X-ray is a strong independent predictor of CV events. Beyond traditional risk factors including endothelial dysfunction, risk stratification by assessment of AAC may provide important information for primary preventive management of atherosclerotic disease.