Framingham risk equation underestimates subclinical atherosclerosis risk in asymptomatic women.
BACKGROUND
Coronary heart disease (CHD) is the leading cause of death among American women. Currently, global risk assessment derived by Framingham risk equation (FRE) is used to identify women at increased risk for CHD. Electron-beam computed tomography (EBCT) derived coronary artery calcium (CAC) scores are validated markers for future CHD events among asymptomatic individuals. However, the adequacy of FRE for identifying asymptomatic women with CAC is unknown.


RESULTS
We studied 2447 consecutive non-diabetic asymptomatic females (55 +/- 10 years). Based upon FRE, 90% were classified as low-risk (FRE < or = 9% 10-year risk of hard CHD events), 10% intermediate-risk (10-20%), and none were considered as high-risk (> 20%). Coronary artery calcium was present in 33%, whereas CAC > or = 100 and CAC > or = 400 were seen in 10 and 3% of women, respectively. Overall, 20% of women had age-gender derived > or = 75th percentile CAC. According to FRE, the majority (84%) of women with significant CAC > or = 75th percentile were classified as low-risk. Approximately half (45%) of low-risk women with > or = 2 CHD risk factors and a family history of premature CHD had significant CAC.


CONCLUSIONS
Framingham risk equation frequently classifies women as being low-risk, even in the presence of significant CAC. Determination of CAC may provide incremental value to FRE in identifying asymptomatic women who will benefit from targeted preventative measures.
Michos
Erin D
ED
Ciccarone Preventive Cardiology Center, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
Nasir
Khurram
K
Braunstein
Joel B
JB
Rumberger
John A
JA
Budoff
Matthew J
MJ
Post
Wendy S
WS
Blumenthal
Roger S
RS
D050197:Atherosclerosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D002114:Calcinosis / Q000000981:diagnostic imaging; D003331:Coronary Vessels; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D008962:Models, Theoretical; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D014057:Tomography, X-Ray Computed