Atherosclerosis surrogate imaging trials come of age: for better or for worse?

Surrogate atherosclerosis imaging trials have been used to evaluate drugs for regulatory approval. These imaging trials have focused on two methodologies: carotid B-mode ultrasound to measure carotid intima-media thickness (CIMT) and coronary intravascular ultrasound (IVUS) to assess atheroma volume. Recent controversies exist regarding the clinical use of these imaging trials. However, a review of the published CIMT and IVUS trials demonstrates consistent results if the trial is conducted in a coordinated fashion. Proper patient selection appears to be an important criterion to ascertain valid results, especially for CIMT trials. In light of the cost and time involved to complete morbidity trials demonstrating the benefit of potential antiatherosclerotic agents, surrogate imaging trials are necessary to expedite the regulatory approval process.