Intima Media Thickness Variability (IMTV) and its association with cerebrovascular events: a novel marker of carotid therosclerosis?

Purpose: Increased intima-media thickness (IMT) is an early marker of atherosclerotic disease and several prospective studies have demonstrated that IMT is a strong predictor of cerebrovascular complications. In this paper we propose a novel method to assess IMT, called "intima media thickness variability" (IMTV) and evaluate its relationship with the development of cerebrovascular events.

Material and methods: The study was approved by the local IRB. Twenty consecutive patients underwent ultrasound analysis of the carotid arteries (mean age 68 years; age range 59-81 years). The IMT and IMTV of the 40 carotid vessels was assessed. Bland-Altman statistics were employed to measure the inter-observer variability, and ROC analysis was used to assess the association with cerebrovascular events.

Results: In all cases the ROC area under the curve was higher for IMTV than IMT. There was a statistical significant association between IMTV and cerebrovascular events (P=0.018), but no relationship between IMT and events. The results for inter-observer variability showed a systematic error between 0.04 and 0.08 mm. In the Person Rho correlation analysis in no case a statistical association between IMT and symptoms was detected whereas in 2 cases (observer 1 and observer 2), a statistically significant association between IMTV and symptoms was found.

Conclusions: Data of this preliminary study suggest that IMTV may represent a powerful method to assess carotid atherosclerotic disease with a significant association to cerebrovascular events.