Carotid intima-media thickness (CIMT)

Carotid intima-media thickness (CIMT) is the B-mode ultrasound measurement of the combined thickness of the intima and media layers of the common carotid artery wall, serving as a surrogate marker for subclinical atherosclerosis and vascular ageing. CIMT increases progressively with age and is elevated in the presence of traditional cardiovascular risk factors; population-based studies established associations with incident myocardial infarction, stroke and all-cause mortality, and it was incorporated into risk calculators in the early 2000s. However, the randomised METEOR and other statin trials showed that reductions in CIMT did not reliably translate to clinical event reduction, and subsequent meta-analyses questioned its incremental value over traditional risk models, leading major cardiology guidelines to downgrade its routine clinical use. CIMT remains widely used in cardiovascular research as an outcome measure for intervention trials and in observational studies of accelerated vascular ageing.