Long-term intermittent heparin-induced extracorporeal low-density lipoprotein (LDL)-cholesterol precipitation was performed in three men - aged 32, 52 and 56 years - with severe familial hypercholesterolaemia and angiographically demonstrated coronary heart disease. This significantly lowered by 65-70% their LDL-cholesterol concentration and by 48-54% their fibrinogen concentration. Fibrinogen elimination reduced plasma viscosity by 13-14% and clearly raised the transcutaneously measured partial pressure of oxygen by 33-50%. Clinically the improved microcirculation achieved a decrease in angina symptoms: the walking distance of the 52-year-old man increased from about 100 m to 4000 m, the daily need of glyceryl trinitrate falling from an average of 12 to 4 aerosol doses.