The Program on the Surgical Control of the Hyperlipidemias: a status report.

The Program on Surgical Control of the Hyperlipidemias (POSCH) is a multicentered secondary coronary heart disease intervention trial utilizing maximal plasma lipid reduction as achieved by the partial ileal bypass operation. With over 500 patients recruited into this trial at present, the 4-year sequential lipid changes are statistically highly significant and include an approximate 30% plasma total cholesterol and 40% low density lipoprotein (LDL)-cholesterol reduction, with a slight increase in the high density lipoprotein (HDL)-cholesterol and a marked increase in the HDL-cholesterol:LDL-cholesterol ratio of about 75% or higher. A definitive answer to the lipid-atherosclerosis theory corollary--whether a decrease in the plasma cholesterol engenders a reduction in the incidence or severity of atherosclerotic cardiovascular disease--can be expected from these marked lipid changes in POSCH.