Abstract 14280: Cardiovascular Lifetime Risk Predicts Incidence of Coronary Calcification in Low Risk Subjects: Results From the Dallas Heart Study
Background: The absence of coronary calcium (CAC=0) in middle-age is associated with a very low risk for CHD events in the short-term (i.e. < 10 years). However, the long term implications of CAC=0 are uncertain, particularly among individuals with high lifetime risk for CHD. We hypothesized that among individuals with both CAC=0 and low short-term risk, high lifetime risk would be associated with a greater CAC incidence when compared to low predicted lifetime risk.
Methods: Subjects from the Dallas Heart Study initially classified as low short-term (Framingham risk score < 10%) with baseline CAC scores of 0 who underwent serial CAC scanning were included in this study. Lifetime risk was determined based on risk factor burden according to previously described algorithms. Subjects were stratified by lifetime risk status and the proportion with incident CAC was assessed in univariable and multivariable models.
Results: We identified 754 subjects with two CAC scores (6.9 years apart) and both low short-term risk and CAC=0. Among this group, 365 were at low lifetime risk and 389 at high lifetime risk. We observed an overall CAC incidence of 24.1%. CAC incidence was higher among high lifetime risk compared to low lifetime risk participants (Figure). Similarly, annualized CAC incidence was also higher among high lifetime risk participants (4.2% vs. 2.7%). After multivariable adjustment for age, sex and race, high lifetime risk remained independently associated with CAC incidence (OR 1.6; 95% CI 1.12- 2.27; p=0.01).
Conclusion: Among individuals with low predicted short-term risk and CAC=0, high lifetime risk is associated with nearly a 2-fold gradient in CAC incidence. These findings highlight the importance of high lifetime risk among individuals with very low short-term risk.
- © 2013 by American Heart Association, Inc.