Mannheim Carotid Intima-Media Thickness and Plaque Consensus (2004–2006–2011)

TLDR

Intima‑media thickness (IMT) is a surrogate endpoint for cardiovascular outcomes, and carotid plaque—defined as a focal structure ≥0.5 mm or 50 % of surrounding IMT or >1.5 mm—adds further risk; its use relies on ultrasound physics, technical principles, and harmonized acquisition and analysis methods worldwide. The consensus aims to refine criteria that separate early atherosclerotic plaque from IMT thickening. Standardized methods promote homogeneous data collection, enhance trial power, and enable large database meta‑analyses. The document advises against serial monitoring of IMT in individual patients.

Abstract

Intima-media thickness (IMT) provides a surrogate end point of cardiovascular outcomes in clinical trials evaluating the efficacy of cardiovascular risk factor modification. Carotid artery plaque further adds to the cardiovascular risk assessment. It is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. The scientific basis for use of IMT in clinical trials and practice includes ultrasound physics, technical and disease-related principles as well as best practice on the performance, interpretation and documentation of study results. Comparison of IMT results obtained from epidemiological and interventional studies around the world relies on harmonization on approaches to carotid image acquisition and analysis. This updated consensus document delineates further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT. Standardized methods will foster homogenous data collection and analysis, improve the power of randomized clinical trials incorporating IMT and plaque measurements and facilitate the merging of large databases for meta-analyses. IMT results are applied to individual patients as an integrated assessment of cardiovascular risk factors. However, this document recommends against serial monitoring in individual patients.