Relationship of Thoracic Aortic Calcium to Coronary Calcium and its Progression (From the Multi-Ethnic Study of Atherosclerosis [MESA])

Abstract

Thoracic aortic calcium (TAC) has been associated with a higher prevalence of coronary arterial calcium (CAC). The purpose of this study was to assess the relationship between TAC with both incident CAC and CAC progression in a cohort from the Multi-Ethnic Study of Atherosclerosis (MESA). MESA is a prospective cohort study of 6,814 participants free of clinical cardiovascular disease at entry who underwent non-contrast cardiac computed tomography scanning at baseline examination and at a 2 year follow up. We investigated the independent association between TAC and incident CAC among those without CAC at baseline and between TAC and CAC progression among those with CAC at baseline. The final study population consisted of 5,755 (84%) individuals (62±10 years, 48% males) who had a follow up CAC score an average of 2.4 years later. Incident CAC was significantly higher among those with TAC versus without TAC at baseline (11 per 100 person years versus 6 per 100 person years). Similarly, TAC was associated with a higher CAC change (p<0.0001) in those with some CAC at baseline. In demographic & follow-up duration adjusted analysis, TAC was associated with both incident CAC (RR 1.72; P < 0.0001) as well as with a greater CAC change (RR for 1(st) and 4(th) quartiles and 95% CI: RR 2.89; −3.16, 8.95; RR 24.21; 18.25, 30.18. In conclusion, TAC is associated with incidence and progression of CAC. Detection of TAC may improve risk stratification efforts. Future clinical outcomes studies are needed to support such approach.