This study is a randomized clinical trial (RCT) evaluating the effect of omega 3 supplement [with 400mg Eicosapentaenoic acid (EPA) and 200mg docosahexanoic acid (DHA)] on biomarkers of cardiac necrosis (CKMB and troponin I) in patients undergoing elective PCI. Eighty patients planed to do elective PCI will be categorized into two groups. The first group will be received standard regimen for PCI (aspirin, clopidogrel, and heparin) and the second group will be treated with standard regimen in addition to 3 gram omega 3 (12 hours before PCI). Blood samples will be drawn in all patients before and 8 and 24 h after intervention for cardiac biomarkers assessment (CK-MB, troponin I)and inflammation marker C-reactive protein (CRP). Major adverse cardiac events (MACE) will be evaluated as a second endpoint.