The objective of this study is to verify the relationship between coronary plaque regression and cardiovascular prevention in long term follow up of the Japan Assessment of Pitavastatin and Atorvastatin in Acute Coronary Syndrome (JAPAN-ACS) study [NCT00242944]. In addition, the effect of serum lipid levels or different type of statins on cardiovascular prevention will also be examined.

Several previous multicenter studies using intravascular ultrasound (IVUS) imaging have revealed that statins attenuate the progression of atherosclerosis or even provide regression of plaque volume. Indeed, the Japan Assessment of Pitavastatin and Atorvastatin in Acute Coronary Syndrome (JAPAN-ACS) trial [NCT00242944] has revealed that early aggressive statin therapy in patients with acute coronary syndrome (ACS) significantly reduces the plaque volume of non-culprit coronary lesions On the other hands, a direct relationship between atheroma progression and regression on IVUS and clinical events has not been clearly defined. To verify that relationship, long term follow up of the JAPAN-ACS study will be performed. Clinical outcome of patients with regressed plaque and progressed plaque will be compared. In addition, the objectives of this study are to evaluate the effect of serum lipid levels or different type of statins on cardiovascular prevention.

At the enrollment of original study

Inclusion Criteria:

• Patients with written consent by their own volition after being provided sufficient explanation for their participation in this clinical trial
• Patients 20 years or older at the time of their consent
• Patients with hypercholesterolemia as defined by any of the following criteria:

TC >= 220 mg/dL; LDL-C >= 140 mg/dL; Cholesterol-lowering treatment is necessary in accordance with the investigator's judgement when LDL-C >= 100 mg/dL or TC >= 180 mg/dL.

• Patients who have been diagnosed with acute coronary syndrome
• Patients with successful percutaneous coronary intervention (PCI) by intravascular ultrasound (IVUS) guidance
• Patients having coronary plaques (>= 500 µm in thickness or 20% or more in % plaque) at >= 5 mm from the previously treated area in the same branch of coronary artery

Exclusion Criteria:

• Patients with bypass graft or in-stent restenosis at the site of PCI
• Patients who had received PCI on the lesion in the past where the evaluation of coronary plaque volume is planned
• Patients who had plaques in a non-culprit site and might receive PCI during the treatment period
• Patients receiving lipid-lowering drugs (statins, fibrates, probucol, nicotinic acid or cholesterol absorption inhibitors)
• Patients with familial hypercholesterolemia
• Patients with cardiogenic shock
• Patients receiving cyclosporine
• Patients with any allergy to pitavastatin or atorvastatin
• Patients with hepatobiliary disorders
• Pregnant women, women suspected of being pregnant, or lactating women
• Patients with renal disorders or undergoing dialysis
• Patients who are ineligible in the opinion of the investigator

Cohort of participants of JAPAN-ACS trial who completed the study