Carotid intima-media thickness determined vascular age and the Framingham Risk Score

We examined carotid intima-media thickness (CIMT)-determined vascular age on the Framingham Risk Score (FRS) and the Framingham Heart Age in patients of diverse ethnic origin without a history of diabetes or established cardiovascular disease. In this cross-sectional study, 2291 men and women had CIMT obtained by high resolution B-mode ultrasound in a routine examination between August 1, 2000 and October 1, 2001. We randomly split the population into a training subset (n = 1114) and an analysis subset (n = 1177) using the training subset to regress the average CIMT for each individual on chronologic age. We compared the FRS using CIMT-determined vascular age versus chronologic age in the analysis subset. On average, CIMT-determined vascular age was less than chronologic age, which was less than FRS-heart age in all gender and ethnic groups. For estimated 10-year cardiovascular-disease risk among non-Hispanic whites, only 45.5% of male and 55.6% of female patients were concordant for both measures, and simple Kappa values were low (0.28 for males, 0.32 for females). Among non-Hispanic whites, 40.7% of males and 32.1% of females had greater risk using chronologic age rather than when using CIMT-determined vascular age. Conversely, 13.8% of males and 12.3% of females had a greater risk using CIMT-determined vascular age rather than when using chronologic age. A similar pattern was noted in the other ethnic groups. Our results suggest that CIMT may be very useful in improving risk discrimination in the FRS, and that substituting CIMT-determined vascular age may improve individual cardiovascular risk prediction.