Abstract 14240: Thoracic Aortic Calcium for the Prediction of Stroke Mortality: The Coronary Artery Calcium Consortium

Abstract

Introduction: Thoracic aortic calcium(TAC) is an important marker of extra-coronary atherosclerosis with known predictive value for all-cause mortality. We sought to explore the predictive value of TAC for stroke mortality, independent of the more established coronary artery calcium score. Methods: The Coronary Artery Calcium(CAC) Consortium is a retrospectively assembled database of 66,636 patients aged ≥18 years with no prior history of cardiovascular disease, who had CAC scans done for risk stratification and were followed-up for an average of 12±4years. CAC scans capture a view of the adjacent thoracic aorta, enabling us to assess TAC at no extra cost. TAC was analyzed as present or not present and we restricted analysis to those with this information available. To account for competing risks for death from other causes, we utilized multivariable-adjusted competing risk regression models adjusted for traditional cardiovascular risk factors (age, sex, hypertension, hyperlipidemia, cigarette smoking, diabetes, family history of CHD) and CAC score. We report the relationship between TAC and stroke mortality using sub-distribution hazard ratios(SHR) with 95% CI. Results: There were 41,066 patients with information on TAC, 110 of whom had stroke mortality. The mean age of participants was 53.8±10.3 years, with 34.4% female. The unadjusted SHR for stroke mortality among those who had TAC compared to those who did not was 8.80(95%CI:5.97,12.98). After adjusting for traditional risk factors and CAC score, the SHR was 2.21(95%CI:1.39,3.49). The fully adjusted SHR for females was 3.42(95%CI:1.74,6.73) while for males it was 1.55(95%CI:0.83,2.90). Conclusion: TAC was predictive of stroke mortality independent of traditional risk factors and CAC, more so in females. The presence of TAC appears to be an independent marker of stroke mortality risk though further research is needed to study its incremental value over existing cardiovascular risk prediction models.