Biochemical Effects of Remote Ischemic Pre-Conditioning on Contrast-induced Acute Kidney Injury

Inclusion Criteria: * Patient with non-ST elevation myocardial infarction or unstable angina * Referral for cardiac catheterization and percutaneous coronary intervention * Contrast-induced acute kidney injury risk score of ≥11 Exclusion Criteria: * Inability to give informed consent * unstable blood pressure (systolic blood pressure \> 200 or \<90 mmHg) * History of allergy to contrast media * Peripheral vascular disease of upper limb * Renal disease requiring dialysis * Placement of arteriovenous fistula and arteriovenous graft