• the percent change in coronary plaque volume the percent change in integrated backscatter signal obtained by integrated backscatter IVUS [ Time Frame: 10M ]
  

• absolute change from baseline in coronary plaque volume [ Time Frame: 10M ]
  
• absolute and percent changes in minimal lumen diameter(MLD) and percent(%) stenosis [ Time Frame: 10M ]
  
• absolute and percent changes in total cholesterol(TC);low-density lipoprotein(LDL)-cholesterol(LDL-C) [ Time Frame: 10M ]
  

Previous mega trials have demonstrated that lipid lowering therapy with HMG-CoA reductase inhibitors (statins) reduces the incidence of major cardiovascular events by one-third, thus, the benefit of lipid lowering therapy has been substantiated. Such a benefit is significant especially for patients with coronary heart disease (CHD). The third report of the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP-III) has suggested the advantage of more intensive lipid lowering therapy with a goal of reducing LDL-C below 70 mg/dL for such patients categorized as very high risk. In Japan, Japan Atherosclerosis Society (JAS) Guidelines for Diagnosis and Treatment of Atherosclerotic Cardiovascular Diseases 2002 have recommended that an LDL-C goal for patients with coronary heart disease should be below 100 mg/dL. However, there is no satisfactory evidence whether we need to lower LDL-C level less than the 70mg/dL or not in Japanese population.

Recently, research on diagnosis of coronary plaque has shown significant advances. The REVERSAL study in patients with a history of CHD, by diagnosis with intravascular ultrasound, suggested that intensive lipid lowering therapy with atorvastatin (80 mg/day) was associated with no growth of plaque (-0.4% compared to baseline), whereas therapy with pravastatin (40 mg/day) showed a slight increase (2.7%) in plaque volume over 18 months in Western population.

In Japanese population, MEGA study have shown the effect of moderate lipid lowering therapy in primary prevention of cardiovascular events. However, the effect of moderate lipid lowering therapy in secondary prevention of cardiovascular events is unknown.

Pravastatin and fluvastatin are the statin which has been administered in Japan for several years.

Although LDL-C lowering effect of these statins were less strong than new generation statins, their safeｔｙ profile have been well established. Fluvastatin were expected to reduce coronary plaque because of its high affinity to arterial tissue and antioxygenic effect compared with pitavastatin, but the effect on human coronary plaque has not been reported.

Relative plaque regression rate between intensive and moderate lipid lowering therapy would clarify the ideal level of target LDL-C in Japanese population. Furthermore, the different effect on coronary plaque between pravastatin and fluvastatin which have similar LDL-C lowering effect and different affinity to arterial tissue would determine the superior lipid lowering regimen to affect coronary plaque volume.