BACKGROUND AND OBJECTIVES: Angiotensin II type 1 receptor blocker (ARB) has been to attenuate neointimal formation and vascular smooth muscle cell proliferation, with decreased inflammation. Recent studies have demonstrated that statins may contribute to the beneficial effects of ARB toward vascular diseases. The aim of this study was to evaluate the beneficial effects of the combination therapy of ARB and statin compared to that of angiotensin converting enzyme (ACE) inhibitor and statin in acute coronary syndrome (ACS) patients who underwent percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: 396 patients with ACS, who underwent PCI between June 2002 and December 2003, were divided into two groups: the ARB and simvastatin (n=188, 61.2+/-10.3 years, male 72%) and ACE inhibitor and simvastatin groups (n=208, 60.9+/-10.6 years, male 66%). The major adverse cardiovascular events, including restenosis and repeat PCI, between the two groups were compared. RESULTS: At 6-month after PCI, the levels of total cholesterol, triglyceride and low-density lipoprotein cholesterol were significantly decreased and that of high-density lipoprotein cholesterol significantly increased, and the levels of high-sensitivity C-reactive protein, fibrinogen, white blood cell and monocyte significantly decreased in both groups. A quantitative coronary angiography analysis of stented coronary segments disclosed no differences in the minimum lumen diameter and stent length. At the 6-month follow-up angiogram, there were no significant differences in the incidence of restenosis and repeat PCI, and there was also no difference in late loss between the two groups (ARB and statin group: 20%, 18%, 0.78+/-0.38 mm vs. ACE inhibitor and statin group: 22%, 20%, 0.81+/-0.44 mm). There were no significant differences in the incidence of cardiac deaths, myocardial infarctions, cerebrovascular accidents and bypass grafts at the 1-year clinical follow-up between the two groups. The event-free survival rates at 1 year were 81 and 79% in the ARB and statin and the ACE inhibitor and statin groups, respectively. There were no differences in the late loss and major adverse cardiac events according to the used ARBs or ACE inhibitors. CONCLUSION: The combination therapy of ARB with statin might not show more beneficial effects compared to ACE inhibitor with statin in ACS patients having undergone PCI.