1. Use of Current CAC Guidelines and CAD Risk Evaluation in Asymptomatic Adult Women
Gina Lundberg MD, Quira Woodbury MSc, Stacy Jaskwhich NP, Kevin Viel PhD, Jason Reingold MD, Austin S. Lam BS
Background: The 2010 ACCF/AHA Guideline for the Assessment of Cardiovascular Risk in Asymptomatic Adults recommends that Computed Tomography for Coronary Artery Calcium (CAC) is reasonable in intermediate risk patients (10 to 20% 10-year risk) with a Class IIa indication. Therefore, adults with a Framingham or Reynolds Risk score in the low risk category are not felt to benefit from CAC screening. Many studies, however, have reported the usefulness of CT for CAC in risk assessment and many studies have reported that Framingham and Reynolds underestimates risk in younger aged women. The Guidelines also give a Class IIb indication for low to intermediate risk adults (6 to 10% 10-year risk) and a Class III indication for low risk adults.
Objectives: We wanted to determine if the new guidelines for screening asymptomatic adults would appropriately identify women at risk for cardiovascular disease. We also wanted to determine if CAC testing improved risk stratification in the low risk women.
Methods: An outpatient cardiovascular screening program in a suburban area of a major city evaluated 500 asymptomatic women between 2007 and All women had testing to determine Framingham Risk Score, Reynolds Risk Score and AHA Women’s Risk level. The age range was years old, mean 52 yrs and SD Women were offered CAC assessment as part of the program. All women with positive CAC scores were referred to cardiologists for further evaluation and medical treatment when appropriate.
Results: Of the women screened, one-hundred sixty women elected to have CT for CAC. 33% of the women with a Framingham risk score in the low risk range and 34% of the women with a Reynolds score in the low risk range had a CAC score greater than or equal to one.
Figure 2: This figure (above) demonstrates discrepancy between Framingham and Reynolds Risk Classifications and Computed Tomography for Coronary Artery Calcium. 33% of women who had a Framingham risk score in the low risk range and 34% of women who had a Reynolds risk score in the low risk range scored greater than or equal to 1 on Computed Tomography for Coronary Artery Calcium.
Figure 1: This figure (above) shows a representative image of Computed Tomography for Coronary Artery Calcium. Arrows Point to Areas of Calcium.
Figure 3: These figures (left) show criteria for risk classification via the Framingham risk score. The figure (far left) shows each risk factor and a correlative point value. The figure (left) shows total risk points and how they relate to 10 year CVD risk.
Conclusion: None of these women who were low risk by Framingham and Reynolds Risk Scores would have been reclassified to a higher level of risk without the CT for CAC. Based on this information, the current guidelines for cardiovascular risk in asymptomatic adults underestimate risk in women age