Abstract P318: Risk factors for 10-year coronary artery calcium progression in the Multi-Ethnic Study of Atherosclerosis
Coronary artery calcium (CAC) progression has previously been observed to predict coronary events above and beyond its association with baseline CAC. Prior studies show associations between CAC progression and risk factors, but were limited by short follow-up or restriction to individuals with advanced disease. We examined the relationship between risk factors for clinical events and the progression of CAC in MESA, a prospective cohort study.
Participants were 6810 adults without CVD at recruitment in 2000-2002. Agatston scores for extent of calcification were assessed 1-4 times (mean 2.5) over a 10-year period with interim exams spaced at approximately 2-4 years. Mean follow-up time for those with at least 2 scans was 5.0 years. An innovative approach to mixed effects models jointly modeled the associations between risk factors and CAC both at baseline and with CAC progression rate. This method is less biased than controlling for baseline CAC, since the same risk factors are associated with both baseline and progression. Hence, time-varying factors can adjust progression rate, and data from participants with varying follow-up time and number of measurements_even those measured only at baseline_are incorporated.
Mean CAC progression rate was 25 CAC units/year. All models were adjusted for age, sex, site, and race/ethnicity. Strong effects were observed for age, male sex, hypertension, and diabetes. Effects for statins likely reflect poor health status, rather than a causal effect of medication. Simultaneous adjustment for all risk factors produced similar results except the effect of statin use was not observed. See table for estimates and confidence intervals.
In conclusion, CAC progression is associated with risk factors for clinical coronary events, confirming that processes involved in CAC progression mirror development of clinical atherosclerosis. The methods applied for the analysis of repeated continuous noninvasive measures of atherosclerosis extent can also be applied to evaluating novel risk factors.
Author Disclosures: A.J. Gassett: None. L. Sheppard: None. R.L. McClelland: None. R.A. Kronmal: None. M.J. Budoff: None. M.J. Blaha: None. J.D. Kaufman: None.
- © 2014 by American Heart Association, Inc.