Effect of lipid-lowering therapy on the progression of coronary atherosclerosis assessed by scheduled repetitive coronary arteriography.

We studied 42 subjects, each of whom demonstrated significant (greater than or equal to 50%) narrowing of a non-grafted coronary artery and a baseline cholesterol level greater than 250 mg%. All patients underwent repeat scheduled coronary arteriography after 2 years on the study. Twenty-five colestipol responders (cholesterol levels reduced at least 15% within 1 month of therapy) were compared to 17 non-responders who were given 23 months of placebo after a 1 month exposure to colestipol. Baseline risk factors and demographic characteristics were similar for the two groups. In comparison to baseline arteriography, only 3 of the 25 drug-treated patients showed progression, while 8 of 17 placebo treated patients demonstrated progression (P = 0.011). Drug-treated patients demonstrated a 20% decrease in cholesterol levels, while placebo patients did not experience a significant reduction in cholesterol levels. Our study suggests that significant reduction in serum cholesterol levels is associated with a reduced likelihood of progression of coronary atherosclerotic lesions assessed by scheduled repetitive coronary arteriography in hyperlipidemic subjects demonstrating significant coronary artery narrowing on their initial arteriograms.