Retrospective Analysis of postoperative acute kidney injury in patients undergoing off-pump coronary artery bypass surgery

Background: Recent study has shown that postoperative acute kidney injury (AKI) increases postoperative mortality and complications, but correlation between perioperative factors in cardiac surgery and AKI still remains to be explored. The present retrospective study was performed to evaluate the predictors of postoperative AKI in patients undergoing off pump coronary artery bypass surgery (OPCAB). Methods: We studied 233 patients undergoing OPCAB at Toyama University Hospital between January 2009 and March 2013. Logistic regression analyses were used to determine whether perioperative factors were associated with postoperative AKI. Results: Postoperative AKI occurred in 39% of the patients. There were statistically significant associations between postoperative AKI and perioperative factors including BMI (multivariable odds ratio, 1.83; 95% CI, 1.14 to 3.88), hypertension (multivariable odds ratio, 1.80; 95% CI, 1.01 to 3.23), intraoperative urine output (multivariable odds ratio, 1.85; 95% CI, 1.02 to 3.39) and postoperative anemia (multivariable odds ratio, 2.24; 95% CI, 1.24 to 4.12). Conclusions: In this study, we found that preoperative BMI, hypertension, intraoperative urine output and postoperative anemia might be predictors of postoperative AKI in OPCAB surgery patients.