Remote ischemic preconditioning (RIPC), elicited by brief episodes of ischemia and reperfusion in distant tissue, offers a protection against acute kidney injury (AKI) in patients after cardiac surgery. Investigators conducted a prospective, randomized, controlled clinical trial to assess whether RIPC reduces the incidence of AKI measured by standard way using serum creatinine concentration (SCr) and with use of serum level of neutrophil gelatinase-associated lipocalin (NGAL) as a new potential biomarker of a kidney injury. Moreover the aim of investigation was to analyse the safety and clinical outcomes of RIPC after elective, isolated, primary off-pump coronary artery bypass graft surgery (OPCAB).