Abstract 17459: Discordance Between Framingham Risk Score and Coronary Artery Calcium in High and Low Risk Populations

Abstract

OBJECTIVE: To evaluate the discordance between Framingham risk score (FRS) and Coronary Artery Calcium score (CACS) in a high risk population at a tertiary health care center in comparison to the low risk MESA (Multiethnic Study of Atherosclerosis) population.

DESIGN AND METHODS: Retrospective analysis and comparison of the MESA and VA Loma Linda Health Care Syst Cardiac CT databases was performed. The VA database included 907 volunteers and patients who underwent imaging for various clinical indications including chest pain, heart failure, abnormal/equivocal stress tests. The MESA database included 6814 asymptomatic individuals selected from the various communities across the US. The mean age and percent male of the VA and MESA databases were 59 and 62 yrs; 90% and 47% respectively. CACS measured in Agatston Units was used as a categorical variable (0, 1-100, 101-300 and >300). FRS was categorized into low (20%) based on 10 year risk of hard events. CACS measured in Agatston Units was categorized as 0, 1-100, 101-300 and >300. Univariate analyses were performed to assess the discordance between these markers.

RESULTS: Significant discordance exists between FRS and CACS, which may allow reclassification of cardiovascular (CV) risk. In the VA and MESA datasets, 21% and 8% of patients with low FRS were noted to have very high coronary calcium score respectively. On the other hand 16% and 29% of patients in the FRS intermediate risk category were noted to have no calcium; whereas 47% and 21% had very high CACS in the VA and MESA datasets. Finally, 11% and 16% of pts in the high risk FRS category had no coronary calcium in the VA and MESA datasets. In both populations, increased mortality was noted with higher calcium scores.

CONCLUSIONS: This study underscores the discordance between FRS and CACS, potentially identifying a significant number of patients who may benefit from aggressive risk factor modification in both high and low risk populations.