Preventive Effect of the PRetreatment With Intravenous Nicorandil on Contrast-Induced Nephropathy in Patients With RenaL Dysfunction UndEergoing Coronary Angiography (PRINCIPLE Study)

Inclusion Criteria: * Patients aged ≥ 20 years * Patients undergoing elective coronary angiogram due to documented myocardial ischemia or symptoms of angina * Estimated Cr clearance ≤60 mL/min by Cockcroft-Gault formula or serum Cr ≥1.1 mg/dL * Signed written informed consent to participate in the study Exclusion Criteria: * Acute myocardial infarction requiring primary or rescue coronary intervention * Allergic reaction to contrast dye or nicorandil * Cardiogenic shock or significant hypotension * Previous use of nicorandil within the preceding 7 days * Exposure to contrast medium within the preceding 7 days * Pregnancy or women at age of childbearing potential * Heart failure (NYHA class III or IV; LV ejection fraction \<40% by echocardiogram) * Acute renal failure or chronic dialysis * Mechanical ventilation * History of kidney transplantation * Life expectation less than 6 months * Previous renal artery angioplasty within the last 6 months * Use of nonsteroidal anti-inflammatory drugs, intravenous use of diuretics, dopamine, mannitol, N-acetylcysteine, ascorbic acid or sodium bicarbonate within 48 hrs before the procedure * Severe liver disease