Incidence, Risk Factors, and Prediction of Acute Kidney Injury After Off-Pump Coronary Artery Bypass Grafting

Abstract

Background: Acute kidney injury (AKI) is a serious complication after coronary artery bypass grafting and is closely associated with high mortality. The objective of the present study was to identify the incidence and risk factors for AKI after off-pump coronary artery bypass grafting (OPCAB) and to construct a risk model for prediction of AKI after OPCAB. Methods: We retrospectively studied 448 adult patients who underwent isolated OPCAB between April 2006 and July 2007. AKI was defined as an increase in serum creatinine of 0.3 mg/dL or 50% within 48 h after surgery. Multivariate analysis was used to evaluate risk factors for AKI after OPCAB and a risk model was developed with a weighted score based on the odds ratio. Results: The incidence of AKI was 7.6% (n = 34). Most patients (97%) had mild AKI. Independent preoperative risk factors of postoperative AKI were identified as high systolic blood pressure, decreased glomerular filtration rate, and coronary angiography (CAG) less than 7 days prior to OPCAB. The incidence of AKI across each increasing score level increased from 2.2% to 60%. Conclusion: AKI after OPCAB was common. High systolic blood pressure, renal dysfunction, and CAG less than 7 days prior to cardiac surgery were associated with AKI after OPCAB. Our risk model may provide information to clinicians and patients about the risk of postoperative AKI.

• acute kidney injury
• off-pump coronary artery bypass
• risk
• incidence
• prediction