Abstract 10053: Progression of Coronary Calcium and Incident Coronary Heart Disease Events: The Multi-Ethnic Study of Atherosclerosis (MESA)
Background: Coronary artery calcium (CAC) is a strong predictor of future coronary heart disease (CHD) events in asymptomatic adults; however, the incremental prognostic importance of CAC progression is not established. We examined whether progression of CAC, independent of baseline CAC is an important predictor of future CHD events.
Methods: We studied 5,660 persons (53% female) from MESA, a multicenter cohort study including 4 ethnic groups aged 45-84, who had risk factor measures and baseline and repeat CT scans (mean 2.4 years later) for measurement of CAC volume (in cc), without inter-scan CHD event. These persons were followed for CHD events (mean 2.4 year follow-up after scan 2). Cox proportional hazards regression was utilized to examine the relation of positive change in CAC by tertile (compared to 0 or negative change), with hard (myocardial infarction) and total CHD events, adjusting for age, gender, ethnicity, baseline calcium score, and other risk factors. Analyses were also done by quartile of CAC change in those with CAC>0 at baseline (n=2,733).
Results: The table below shows event rates and the adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for total CHD by category of annual absolute change in CAC volume. A total of 163 CHD events occurred (97 hard), of which 145 (83 hard) were in persons with CAC>0 at baseline. Relationships with hard CHD (total CHD excluding angina) were of similar magnitude and strength but slightly attenuated in those with CAC>0 at baseline.
Conclusions: Progression of CAC is associated with a 4.6 fold increased incidence of CHD events, independent of baseline CAC score and risk factors. To date, only statin therapy has been shown to reduce cardiovascular events in patients with positive CAC scans.
- © 2011 by American Heart Association, Inc.