Abstract 13805: Associations of Subclavian Artery Calcification With Future Cardiovascular Events and Death: The Multi-Ethnic Study of Atherosclerosis

Abstract

Introduction: Atherosclerosis affects the upper limbs and may be a marker of diffuse atherosclerosis and increased risk for cardiovascular events. Hypothesis: Subclavian artery calcification (SAC) and thoracic aorta calcification (TAC) obtained by chest CT provide additional information about future CV events and death beyond coronary artery calcification (CAC) and CV risk factors. Methods: Chest CT scans of MESA participants (N = 2519) at exam 5 (2016-18) were interrogated for the presence and extent of SAC, TAC, and CAC. Proportional hazards regression was conducted for associations with incident total CVD events (n = 209), adjusted for age, race/ethnicity, and sex, then SAC, TAC, and CAC adjusted for demographics and each other, and finally adding adjustment for CV risk factors. Results: The mean age of the sample was 68.3±9.2 years; 48% were male, 27% Black, 13% Chinese, 22% Hispanic, 38% White. The prevalence of any calcification was 62% for SAC, while being 60 and 69% for TAC and CAC, respectively. Among those with any calcification, N and median Agatston score were SAC: 1704, 76; TAC: 1655, 152; CAC 1896, 135. CAC predicted future events in all models (Table). After adjustment for demographics, the ln(Agatston score +1) in each calcified vascular bed predicted future CVD. Mean±SD of the predictors were ln(SAC+1): 2.4±2.4, ln(TAC+1) 2.7±2.9 and ln(CAC+1) 3.1±2.6. SAC, but not TAC, was still predictive after mutual adjustment. SAC was marginally predictive (HR: 1.08, p = 0.06) when CV risk factors were also included in the model. Conclusions: Calcification was common in all 3 vascular beds, but there is no evidence that predictions using SAC and TAC are independent of CAC. We speculate that although the tendency to calcify is similar across vascular beds, CAC is most relevant for incident CVD.