Measurement of carotid artery intima-media thickness in dyslipidemic patients increases the power of traditional risk factors to predict cardiovascular events

A longitudinal observational study investigated whether the measurement, in clinical practice, of carotid maximum intima-media thickness(Max-IMT) could be combined with the Framingham risk score (FRS) to improve the predictability of cardiovascular events in dyslipidemicpatients who are at low or intermediate risk.Max-IMT was measured by ultrasound in 1969 patients attending a lipid clinic. The “best threshold values” (BTVs) above which weconsidered the Max-IMT to be abnormally high were calculated for our dyslipdemic population for each 10-year age interval in men andwomen. Two hundred and forty-two patients (age 54±10 years; 43.8% women) with an FRS <20%, i.e. at low or intermediate risk, weremonitored for more than 5 years. Twenty-four of these patients suffered a cardiovascular event within 5.1±2.3 years. Both FRS and Max-IMTproved to be independent outcome predictors (p < 0.04, both), with a hazard ratio (HR) of 6.7 (95% CI 1.43, 31.04; p=0.015) in patientsin whom FRS was 10–20% and Max-IMT was above the BTV (60th percentile of Max-IMT distribution for men or 80th for women). InKaplan–Meier analysis, the Max-IMT significantly improved the predictive value of the FRS (χ2 = 8.13, p=0.04). Patients with FRS 10–20%(currently considered intermediate-risk) and also elevated Max-IMT values came into the same high-risk category as patients withFRS20–30%.The combination of FRS with Max-IMT measurement can be used in routine clinical practice to greatly enhance the predictability ofcardiovascular events in the large number of patients who fall into the intermediate-risk category, which currently does not call for aggressivepreventive measures