Young survivors of myocardial infarction represent a poignant challenge to clinical research on atherogenic mechanisms and factors predisposing to and precipitating coronary thrombosis. Young male postinfarction patients are characterized by heavy smoking, dyslipoproteinaemias involving very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL), a family history of premature coronary artery disease, hyperinsulinaemic responses to oral and intravenous glucose challenges, an elevated plasma fibrinogen concentration and defective fibrinolytic function. Based on the multiplicity of metabolic and haemostatic disturbances present in these patients, a double-blind, randomized, placebo-controlled angiographic trial was initiated to determine whether bezafibrate, a clofibrate analogue, retards the progression or facilitates regression of premature coronary atherosclerosis. Men under the age of 45 years who survived a first myocardial infarction were screened for participation in the study. A fasting serum cholesterol value > or = 5.2 mmol/l and/or serum triglycerides > or = 1.6 mmol/l after three months of dietary treatment and angiographically demonstrable lesions in at least one coronary segment were required for inclusion. Treatment with diet and bezafibrate (200 mg t.i.d.) or matching placebo is continued for five years during which time re-angiography is performed after two years and at the end of the study. The primary aim of the trial is a comparison between the bezafibrate and placebo groups for change in mean minimum luminal diameter between the baseline and five-year coronary angiograms. This report presents the design features of the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT) and a review of current knowledge of mechanisms underlying premature coronary atherosclerosis and myocardial infarction at a young age.