Abstract 18376: Long-term Atherosclerotic Cardiovascular Disease Outcomes Associated With Coronary Artery Calcium
Introduction: Current risk assessment guidelines focus on prevention of atherosclerotic cardiovascular disease (ASCVD), which includes stroke as a primary outcome variable. The long-term (>10 year) relationship of coronary artery calcium (CAC) scoring with stroke has not been previously reported, a limitation cited by the guidelines. Further, large-scale, long-term outcomes studies following CAC are limited. We sought to define the long-term relationship of CAC for stroke and myocardial infarction (MI) in a large screening cohort.
Methods: We retrospectively identified 24,246 subjects (mean age 50±8; 70.5% men) without ASCVD or malignancy who underwent CAC scoring (Agatston) at Walter Reed Medical Center from 1997-2009. Subjects were assessed for the primary outcomes of MI and stroke and the secondary outcome of late (>90 days post CAC) coronary revascularization. Outcomes were extracted from the military data repository, a comprehensive healthcare database that captures care provided within and outside of the military healthcare system, and then analyzed using Cox proportional hazard multivariate stepwise regression controlling for baseline risk factors.
Results: With a mean follow-up of 11.3±3.6 years there were 546 MI, 947 strokes and 843 late coronary revascularizations. Compared to subjects with no CAC, the adjusted hazard ratios (aHR) for MI were 2.09 (95% CI, 1.68-2.60), 2.01 (1.78-2.28) and 1.91 (1.72-2.11) for CAC scores of 1-100, 101-400 and >400, respectively. CAC of 1-100 was not predictive of stroke compared to no CAC. The aHRs of incident stroke were 1.15 (1.03-1.28) and 1.23 (1.13-1.33) for CAC scores of 101-400 and >400. CAC was strongly associated with late coronary revascularizations. CAC explained the most variance in models for MI and late revascularization and was the third most important predictor for stroke behind age and hypertension.
Conclusion: In patients without ASCVD, CAC was a stronger independent predictor of incident MI and late coronary artery revascularization as compared to stroke over one of the longest follow-up intervals reported to date. Advanced CAC (>100) was a modest independent predictor of stroke during the study period. These results support the role of CAC for the prediction of incident ASCVD outcomes.
Author Disclosures: J.D. Mitchell: None. R. Paisley: None. P. Moon: None. T.C. Villines: None.
- © 2015 by American Heart Association, Inc.