Abstract 9868: Coronary Artery Calcium Predicts Coronary Heart Disease Events Even at the Extremes of Age: The Multi-Ethnic Study of Atherosclerosis
CAC testing to refine risk prediction is utilized in intermediate-risk asymptomatic patients, largely excluding elderly and young patients who are typically classified as high- or low-risk due to the influence of age in risk-scoring algorithms. The clinical utility of CAC in predicting coronary heart disease (CHD) events in patients at extremes of age remains to be explored.
Methods: The MESA cohort was followed up for a median of 5.8 years. The primary endpoint of CHD events was assessed in the following age groups: 45-54, 55-64, 65-74, and 75-84 years. Cox regression analysis was employed to determine the interplay of CAC and aging in predicting CHD events after adjusting for demographic factors, traditional risk factors, and medication use.
Results: Of 6,809 participants, 278 (4%) CHD events were noted. The prevalence of CAC=0 was 75% in the 45-54 age group, decreasing progressively with increasing age (75-84 yr=19%, p<0.0001). Conversely, CAC >100 increased from 6% in the 45-54 age group to 51% in the elderly. After adjusting for age, demographic and cardiovascular risk factors, CAC>100 predicted a significantly increased CHD event rate compared to CAC=0 in both the young and elderly (45-54: HR 8.29 [95% CI 2.84-24.16], 75-84: HR 8.34 [95% CI 2.11-36.92]). Increasing age group was associated with a statistically significant increased risk of CHD events, compared to the 45-54 year old group, even after adjusting for risk factors and CAC (HR [95% CI], 55-64 yr: 1.71[1.06-2.74], 65-74 yr: 1.75 [1.10-2.79], 75-84 yr: 1.95 [1.17-3.25]).
Conclusions: Greater CAC burden was associated with increased CHD events in all age groups, adding incremental prognostic value in both young and elderly patients. Young individuals with CAC>100 had a higher CHD event rate compared to older individuals with no CAC. Increasing age was independently associated with higher event rates, confirming that atherosclerotic burden cannot completely explain the association of aging with CHD events.
- © 2011 by American Heart Association, Inc.