If patients with coronary artery disease are followed by "usual care" nearly half of them will experience significant progression of their disease within five years. Therefore, it is justified to develop interventions in order to retard the rate of progression and reduce the number of clinical events. In relevant studies published up to this date two different strategies were applied, first, reduction of risk factors by low fat diet, physical exercise, lipid lowering agents or partial ileal bypass; second, inhibition of atherogenesis by application of calcium blocking agents. The effect on progression of coronary artery disease was assessed by digital angiography in the majority of studies; without exception a positive effect was noted in all of them. In the calcium blocker studies this effect, however, was limited to new or minimal lesions. The magnitude of morphological difference between intervention and control groups ranged below 0.5 mm and thus approached the long term variability of quantitative coronary angiography. The frequency of clinical events was reduced in only two studies, whereas they were increased in four intervention groups.
Conclusions: Reduction of risk factors or application of calcium blockers are capable of retarding progression of coronary artery disease; predominant regression, however, seems to be unattainable. The frequency of clinical events is determined by additional factors other than morphologic changes.