Objective: To investigate the incidence rate and risk factors of acute kidney injury (AKI) after off-pump coronary artery bypass grafting (CABG),and to compare the effects of AKI on complications after operation and major adverse cardiovascular and cerebrovascular events (MACCE) after 3 years' follow-up.
Methods: In the study, 299 consecutive patients who underwent scheduled off-pump CABG from January 2010 to March 2012 were included. The patients were divided into AKI group with AKI and control group without AKI after operation. The data during perioperative stage were compared, and multivariable Logistic regression modeling was used to identify the risk factors of AKI. The complications were compared after surgery and the patients were followed up for 3 years to observe the difference of MACCE between the two groups.
Results: AKI occurred in 37.1% patients (111/299). The elevated serum creatinine levels(Wald=9.276, P=0.002, 95%CI 1.006-1.028), chronic obstructive pulmonary disease(COPD) (Wald=3.469,P=0.063,95% CI 0.950-7.630), decreased left ventricular ejection fraction(LVEF)(Wald=4.414,P=0.036,95% CI 0.965-0.999),and implantation of intra-aortic balloon pump (IABP) before or after operation(Wald=6.745, P=0.009, 95% CI 1.336-7.925)were risk factors of AKI in multivariable logistic regression modeling. More complications occurred in AKI group, such as the duration of mechanic ventilation, the time of ICU and the length of stay post operation, reintubation, pulmonary infection, stroke, hemorrhage of digestive tract, the volume of blood transfusion (plasma and red blood cell) and renal replacement therapy(P <0.05). The difference of mortality rate had no statistical significance between the AKI group and the control group, but two patients died in the AKI group. The difference of MACCE between the two groups had no statistical significance after 3 years' follow-up either.
Conclusion: The incidence of AKI was high (37.1%) after off-pump CABG. The elevated serum creatinine levels, COPD, decreased LVEF,and implantation IABP before or after operation were independent risk factors of AKI in multivariable Logistic regression modeling. More complications occurred in AKI group during perioperative period, but the difference of MACCE between the two groups after 3 years' follow-up had no statistical significance.