Carotid intima-media thickness is increased in subjects with ischemic heart disease having a familial incidence.

Ischemic heart disease (IHD) causes severe morbidity and mortality, although the specific risk factors are unknown. Accumulating evidence indicates that a family history of IHD is a risk factor for cardiovascular events (1–3). However, the mechanisms underlying this susceptibility have not been fully elucidated. We hypothesize that an important mediator of the familial incidence of IHD is premature atherosclerosis, which is detectable by noninvasive imaging. B-mode ultrasonography is a useful tool for detecting atherosclerotic changes in the arterial wall (4). Measurement of the intima-media thickness (IMT) of the common carotid artery has been established as an index of early-stage atherosclerosis, and the results are strongly correlated with the presence of IHD (4–6). Accordingly, in a general medical screening trial, we examined the severity of IMT in subjects with a familial incidence of IHD versus those without.