Electron beam tomography as an endpoint for clinical trials of antiatherosclerotic therapy.

Current antiatherosclerotic therapies are highly effective and have induced a factual reduction in morbidity and mortality related to atherosclerotic disease. This makes it difficult for clinical researchers to demonstrate a further reduction in hard events. On the other hand, angiographic studies have conclusively demonstrated that coronary artery disease regression can be used as a valid surrogate endpoint. In fact, small improvements in luminal diameter stenosis corresponded to a substantial reduction in event rates. However, because coronary angiography is invasive and expensive, other surrogate endpoints may be more desirable to ascertain the effectiveness of therapy. With electron beam tomography imaging the coronary artery tree is visualized noninvasively and vascular calcification, a marker of atherosclerotic disease, is easily detected and its extent quantified. Preliminary studies have shown that this technology provides an opportunity to serially monitor the effectiveness of medical therapy for coronary artery disease at low cost and low risk for the patient.