Aortic arch calcification in relation to cigarette smoking: results from the multi-ethnic study of atherosclerosis (MESA)

Abstract

Cigarette smoking is a known contributor to cardiovascular disease (CVD) and is associated with increased prevalence of coronary artery calcium. However, despite this clinical significance, calcium deposition in other vascular beds, specifically the aortic arch, has yet to be thoroughly investigated among cigarette smokers.The study population comprised participants who underwent non-contrast chest CT scans in MESA exam 5 (2010-2012). Aortic arch calcium (AAC) is defined as calcification in the transverse aortic arch, as measured using the Agatston method on chest CT scans. Log-transformed AAC scores were used for all analyses. Multivariable linear regression models were fit to assess the relationship between log-AAC and cigarette smoking status (never-smoked, former smoker, current smoker). Cox proportional hazard models were fit to investigate the relationship between log-AAC and incident CVD and mortality for those with a history of smoking (former & current smokers). All models were adjusted for demographic and traditional clinical risk factors. After excluding those with missing variables or prevalent CVD prior to the chest CT, 2,191 participants were included in the final analysis, of which 1,091 self-identified as never smokers, 918 as former smokers, and 182 as current smokers. Estimated mean log-AAC was 0.58 (p < 0.001) log-Agatston units higher in former smokers compared with never smokers [95% CI: 0.40-0.77], and 1.10 (p < 0.001) log-Agatston units higher in current smokers compared with never smokers [95% CI: 0.76-1.40]. Among ever-smokers (current or former smokers), a one log-Agatston unit increase in AAC was associated with a 20.6% (p = 0.002) greater risk for CVD events [95% CI: 7.4 - 35.5%] and a 12% (p = 0.020) greater risk for mortality [95% CI: 2 - 23%]. This study demonstrated an association between cigarette smoking and AAC scores, with significant differences in AAC among current, former, and never smokers. Furthermore, AAC is associated with incident cardiovascular events and mortality among those with a history of smoking.

Keywords: Aortic arch calcification; Cardiovascular disease; Coronary artery calcium; Coronary artery disease; Risk.