Aortic arch calcification detectable on chest X-ray is a strong independent predictor of cardiovascular events beyond traditional risk factors

Abstract

Objectives: Arterial calcification makes the management of hemodynamics more difficult. Some reports have previously shown that simple assessment of aortic calcification using plain radiography is associated with cardiovascular (CV) events; however, these studies simply assessed whether aortic calcification was present or absent only, without considering its extent. Here, we evaluated validity of grading aortic arch calcification (AAC) to predict new CV events.

Methods and results: We retrospectively reviewed chest X-rays in 239 asymptomatic out-patients who underwent measurement of endothelial function at the 1994-2000 without past history of CV events. The extent of AAC was divided into four grades (0-3). Among these subjects, the follow-up of CV events in 209 patients was completed. At baseline, AAC grade was positively related to age, pulse pressure, diabetes and renal dysfunction. Impairment of endothelial function, as determined by flow-mediated dilation (FMD), was also correlated to increasing AAC grade. Fifty-seven CV events in total occurred during a mean follow-up period of 69+/-45 months. With multivariate adjustment, Kaplan-Meier analysis showed that the incidence was significantly higher in patients with higher AAC grade (grades 2 and 3) than in those with grade 0 or 1 (p<0.01, log-rank test). Two kinds of multivariate Cox-proportional hazards analyses showed the predictive values of AAC grade were significant (hazard ratio, 2.49; p=0.01, 2.56; p<0.01, respectively), and the predictive power was superior to that of renal dysfunction or FMD. In addition, the prediction was valuable even in patients without CKD.

Conclusions: 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 management of atherosclerotic disease.