Lipid-lowering interventions in angiographic trials.

This analysis examines the pooled data from all 14 published randomized angiographic trials (with 16 treatment arms) by type of cholesterol-lowering intervention evaluated, and for all the trials combined. All interventions reduced low density lipoprotein (LDL) cholesterol levels (average reduction, 26%), whereas the effects on high density lipoprotein (HDL) cholesterol and triglycerides varied by type of intervention. Meta-analyses of the angiographic outcomes indicated that treatment reduced the odds for disease progression by 49%, increased the odds for no change by 33%, and increased the odds for regression by 219%. Cardiovascular events were reduced by 47%. Thus, lipid reduction is effective for modifying the angiographic outcome and for reducing the incidence of coronary artery disease events. All types of intervention (lifestyle, drugs, or surgery) had overall favorable effects on angiographic and clinical outcomes. There was no class effect for the statin group of drugs. Surgery (partial ileal bypass) had the most favorable angiographic outcome, possibly because of a longer duration of therapy. Trials with higher baseline LDL levels tended to have more favorable angiographic outcomes. Analyses of in-trial levels of LDL were confounded by baseline levels, and analyses of change in LDL levels in the treatment groups were confounded by not including zero change (i.e., no treatment). It is hypothesized that lowering LDL levels by 30 mg/dl (0.8 mmol/liter) is sufficient on average to modify the angiographic outcome, with modest gains from further reductions in LDL levels.