Comparison of the coronary calcium score with the estimated coronary risk

OBJECTIVES: The role of coronary calcium scoring in coronary risk estimation is not well established. Calcium scoring could provide additional information in a certain subgroup of patients where the calcium score does not match the conventional Framingham risk estimates. We explored the characteristics of such a subgroup. METHODS: The study participants were 1653 asymptomatic persons who underwent routine health screening and calcium scoring using the 16-slice multidetector computed tomography. Risk stratification was performed in five categories both by 10-year Framingham coronary risk and the Agatston coronary calcium score. RESULTS: Risk stratifications by coronary calcium score and absolute risk showed a large discrepancy (difference > or =3 classes) in about 9% of participants. The proportion increased with age (P for trend <0.0001). An exploratory analysis revealed that age (partial R=0.109, P<0.0001) and the presence of the metabolic syndrome (partial R=0.025, P<0.001) were independent variables that accounted for the variance of the residual of regression between the log-transformed value of coronary calcium score and the absolute risk. CONCLUSION: Calcium scoring may be clinically more useful in older (> or =50 years) participants and/or in participants with the metabolic syndrome because of the relatively higher probability of obtaining additional information that the conventional Framingham risk estimation cannot provide.