Methods: Between January 2008 and December 2014, a total of 220 patients (106 males, 114 females; mean age 50.6±14.7 years; range 14 to 79 years) who underwent aortic and mitral valve surgery were retrospectively reviewed. Baseline characteristics of the patients, comorbidities, operative variables, and postoperative outcomes were recorded. The patients were divided into two groups as those with and without acute kidney injury, as assessed by preoperative and postoperative creatinine levels using the Acute Kidney Injury Network Criteria.

Results: Of all patients, 57 developed acute kidney injury. Of these, 12 patients required hemodialysis (stage 1, n=40; stage 2, n=12; stage 3, n=5). The patients with acute kidney injury tended to be older with a higher rate of diabetes mellitus. These patients also had higher rates of postoperative sepsis, bleeding revision, atrial fibrillation, and need for intra-aortic balloon pump with longer intensive care unit and hospital stay. A higher number of patients with acute kidney injury needed packed red blood cell transfusion, compared to those without.

Conclusion: Our study results show that acute kidney injury which is diagnosed with mild postoperative creatinine changes according to the Acute Kidney Injury Network criteria is a prognostically important complication. Age, diabetes mellitus, and blood transfusion are the main risk factors of postoperative acute kidney injury. Therefore, patients should be analyzed carefully preoperatively to prevent short- and long-term results of cardiac surgery-related acute kidney injury.