Abstract 686: Ultrasonographic Changes of Carotid Intima-media Thickness Predict Cardiovascular Events
Introduction: Carotid intima-media thickness (IMT) is a surrogate marker of atherosclerosis that is well known to be an independent predictor of cardiovascular (CV) and cerebrovascular events. Few data are available about the usefulness of ultrasound (US) monitoring of IMT to predict changes in individual risk profile.
Hypothesis: Evaluate the prognostic value of serial changes in carotid IMT in a sample of unselected subjects with CV risk factors
Methods: We prospectively studied 419 patients (46% males, age 62±11 years) with at least one CV risk factor, who underwent a baseline carotid ultrasonography and a second examination at least one year later. IMT was measured by M-mode technique and IM thickening (IMTk) was defined as IMT ≥0,9 mm. Only IMT changes ≥0,1 mm were considered significant. Primary end point was fatal/non fatal CV events. Independent predictors of CV events and their relative risk (RR) with 95% confidence interval (CI) were estimated by Cox models, controlling for clinical covariates.
Results: Hypertension was present in 73% of cases, type 2 diabetes in 22%, hypercholesterolemia in 61% and previous CV disease in 30% (mean average 10 years Framingham risk: 25±15%). The mean clinical follow-up was 7.3±2.9 years (median 6.0 years). The average interval between the first and second US examination was 3.6±2.3 years. The average follow-up after the second exam was 3.8±2.5 years. During the study 171 patients experienced fatal or non fatal CV events. Patients with normal IMT at both baseline and second examination (39%) or with IMTk regression (12%) were compared to those with persistent (32%) or newly developed IMTk (17%). In a Cox model the persistence/development of IMTk was the strongest independent predictor of CV events (RR 39.25, IC 15.95 – 96.60), superior to previous CV disease (RR 1.57, IC 1.01 – 2.48) and diabetes (RR 1.50, CI 1.04 – 2.17) while Framingham risk, baseline IMT, conventional CV risk factors and their changes during follow-up did not enter the model.
Conclusion: Patients with persistent or newly developed carotid intima-media thickening are at the highest risk of future cardiovascular events. Carotid ultrasonography is useful to detect changes in carotid IMT and to identify subjects at high risk who need more aggressive treatments.