Oxygen Preconditioning Prevents Contrast-Induced Nephropathy

INTERVENTION: The control patients were applied intravenous hydration with 0.9 % isotonic saline at a rate of 1ml per kilogram per hour (or 0.5ml per kilogram per hour in the case of low ejection fraction lesser than 40 percent) for 12 hours before and after procedure as the standard prevention. In addition to the standard prevention, the oxygen preconditioning patients were administered 2 litters pre minute of nasal pure oxygen from 15 minutes before the canulation until at the end of procedure. CONDITION: Ischemic Heart Disease Congestive Heart Failure Chronic Kidney Disease Peripheral arterial Disease PRIMARY OUTCOME: Contrast‐Induced Nephropathy : defined as an increase in the serum creatinine concentration of 25 percent or 0.5 mg/dl from the baseline at maximum value obtained within 48 hours after the procedure SECONDARY OUTCOME: sex, age (more than 70‐year‐old), hypertension, diabetes mellitus, dyslipidemia, a history of myocardial infarction, BNP(more than 100pg/ml), anemia, use of ACE inhibitors/ARBs, use of diuretics, use of statins, use of contast‐medium (more than 150ml), eGFR (less than 60ml/min/1.73m2), PaO2 (more than 100 mmHg); As sub‐analysis, among the patients with eGFR under 60ml/min/1.73m2 for CIN high risk group. INCLUSION CRITERIA: The patients who are scheduled for cardiovascular angiography including diagnostic coronary angiography, ventriculography, aortography, and/or coronary or peripheral intervention.