There were few eligible subjects from other centers.

The purpose of this study is to compare the incidence of contrast-induced nephropathy (CIN) following the administration of iopamidol-370 (Iopamiro-370) and iodixanol-320 (Visipaque 320) in patients with chronic kidney disease undergoing coronary angiography.

To compare the incidence of contrast-induced nephropathy (CIN)(an absolute SCr increase 0.5 mg/dL from baseline) following the administration of iopamidol-370 (Iopamiro-370) and iodixanol-320 (Visipaque 320) in patients with chronic kidney disease (serum creatinine level more than 1.5 mg/dL for men and more than 1.3 mg/dL for women or preprocedural estimated glomerular filtration rate(eGFR):15-60 mL/min/1.73 m2) undergoing coronary angiography.

Inclusion Criteria:

• Provides written Informed Consent and is willing to comply with protocol requirements
• Is ≥18 years of age
• Has a documented predose serum creatinine level of ≥1.5 mg/dL for men and ≥ 1.3 mg/dL for women or predose estimated glomerular filtration rate (eGFR) of > 15 and ≤ 60 mL/min/1.73 m2, calculated via the MDRD formula from a SCr obtained within 72 hours of enrollment into the study;
• Is referred for cardiac angiography with or without PCI;
• If at the discretion of the Investigator is receiving or will be receiving a prophylactic medication for renal function, the medication is one that is permitted by this protocol (N acetylcysteine, 1200 mg twice daily on the day before and on the day of the cardiac angiography procedure);
• Undergoes or is scheduled to undergo pre, peri, or post procedure hydration permitted by this protocol, i.e.:
• 154 mEq/L sodium bicarbonate solution, administered intravenously at 3 mL/kg/hr for 1 hour before cardiac angiography, followed by an infusion of 1 mL/kg/hr during and out to 6 hours after cardiac angiography, or 0.9% normal saline administered intravenously at 1 mL/kg/hr for 8-12 hours before cardiac angiography, followed by an infusion of 1 mL/kg/hr during and out to 24 hours after cardiac angiography,for the patients with left ventricular ejection fraction <35% or congestive heart failure (class III in accordance with the classification of the New York Heart Association (NYHA), the rate of infusion decreases to half of the above ordinary rate.

Exclusion Criteria:

• Is a pregnant or lactating female. Exclude the possibility of pregnancy: by laboratory testing on-site at the institution (measurement of serum or urine βHCG) within 24 hours prior to the start of investigational product administration by history (e.g., tubal ligation or hysterectomy, post menopausal with a minimum 1 year without menses)
• Has a history of hypersensitivity to iodine-containing compounds;
• Has unstable renal function (i.e., acute worsening of renal function, as determined by the Investigator, that has been observed in the 7 days prior to enrollment) and/or is in acute renal failure;
• Has end-stage renal disease (i.e., eGFR <15 mL/min/1.73 m2)
• Has severe congestive heart failure (class IV in accordance with the classification of the New York Heart Association (NYHA) ;
• Has uncontrolled diabetes, as determined by the Investigator;
• Has received an iodinated contrast agent within 7 days prior to the administration of the study agent or is scheduled to receive an iodinated contrast agent within 72 hours after administration of the study agent; intake of nephrotoxic drugs within the previous seven days Prior to, during or post the cardiac angiography, is receiving or will be receiving a prophylactic medication to prevent acute kidney injury that is not permitted by this protocol (e.g., theophylline, fenoldopam, etc.);
• Is planned to undergo major surgery (e.g. CABG, valve surgery, etc.) within 48-72 hours after contrast administration;
• Is planned to receive an intravenous diuretic or mannitol as prophylaxis to prevent acute renal injury (Note: chronic administration is allowed);
• Is hemodynamically unstable within 48 hours pre-contrast administration defined as a systolic blood pressure < 90 mmHg or requires pressor or intra-aortic balloon support