In 1982, a 49-year-old Japanese woman had been referred to our hospital for further investigation of her hypercholesterolemia. She was diagnosed as heterozygous familial hypercholesterolemia, because of Achilles tendon xanthoma and a family history of primary hypercholesterolemia. Three years later, she had chest pain on effort and angina pectoris was diagnosed by coronary angiography. At that time, she underwent coronary artery bypass grafting surgery with 2 saphenous vein grafts (SVG). Because more aggressive cholesterol-lowering therapy was needed for secondary prevention of coronary artery disease (CAD), weekly low-density lipoprotein (LDL) apheresis was started postoperatively, combined with drug therapy. Since 1986, her serum total cholesterol levels before and after LDL apheresis remained approximately 200 mg/dl and 90 mg/dl, respectively. Although her coronary sclerosis, including the SVG, did not progress appreciably for a period of 20 years, stenotic changes of the aortic valve developed rapidly at age 70, leading to aortic valve replacement surgery in 2005 at age 72. These findings suggest that careful attention to the progression of aortic valve stenosis is needed for extreme hypercholesterolemic patients even under optimal cholesterol-lowering therapy for the secondary prevention of CAD.