Coronary calcium score improves classification of coronary heart disease risk in the elderly: the Rotterdam study.
OBJECTIVE
The purpose of this study was to examine the effect of coronary artery calcium (CAC) on the classification of 10-year hard coronary heart disease (CHD) risk and to empirically derive cut-off values of the calcium score for a general population of elderly patients.


BACKGROUND
Although CAC scoring has been found to improve CHD risk prediction, there are limited data on its impact in clinical practice.


METHODS
The study comprised 2,028 asymptomatic participants (age 69.6 ± 6.2 years) from the Rotterdam Study. During a median follow-up of 9.2 years, 135 hard coronary events occurred. Persons were classified into low (<10%), intermediate (10% to 20%), and high (>20%) 10-year coronary risk categories based on a Framingham refitted risk model. In a second step, the model was extended by CAC, and reclassification percentages were calculated. Cutoff values of CAC for persons in the intermediate-risk category were empirically derived based on 10-year hard CHD risk.


RESULTS
Reclassification by means of CAC scoring was most substantial in persons initially classified as intermediate risk. In this group, 52% of men and women were reclassified, all into more accurate risk categories. CAC values above 615 or below 50 Agatston units were found appropriate to reclassify persons into high or low risk, respectively.


CONCLUSIONS
In a general population of elderly patients at intermediate CHD risk, CAC scoring is a powerful method to reclassify persons into more appropriate risk categories. Empirically derived CAC cutoff values at which persons at intermediate risk reclassified to either high or low risk were 615 and 50 Agatston units, respectively.
Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
Suzette E
SE
Elias-Smale
Rozemarijn Vliegenthart
RV
Proença
Michael T
MT
Koller
Maryam
M
Kavousi
Frank J A
FJ
van Rooij
Myriam G
MG
Hunink
Ewout W
EW
Steyerberg
Albert
A
Hofman
Matthijs
M
Oudkerk
Jacqueline C M
JC
Witteman
D000368:Aged; D002114:Calcinosis / Q000145:classification / Q000473:pathology*; D003327:Coronary Disease / Q000145:classification* / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors