Risk Factors for Acute Kidney Injury after Cardiovascular Surgery: Evidence from 2,157 Cases and 49,777 Controls - A Meta-Analysis.

PURPOSE:Cardiovascular surgery-associated acute kidney injury (AKI-CS) contributes to mortality and morbidity. However, risk factors accelerating its development are unclear. We identified risk factors for AKI-CS in patients with cardiopulmonary bypass in the hospital surgical intensive care unit to predict and minimize renal complication in future cardiac surgery. METHODS:We analyzed data from 14 case-control studies published prior to June 2014 and indexed in Science Citation Index, PubMed, and other databases to determine the major risk factors for AKI-CS. RESULTS:Analyzed risk factors were divided into three groups: preoperative, intraoperative and postoperative. Preoperative factors included: age (OR, 4.87; 95% CI, 3.50-6.24), NYHA class III/IV (OR, 2.53; 95% CI, 1.32-4.86), hypertension (OR, 1.68; 95% CI, 1.44-1.97), preoperative creatinine (OR, 0.66; 95% CI, 0.18-1.14), peripheral vascular disease (OR, 1.31 95% CI, 1.09-1.57), respiratory system disease (OR, 1.29; 95% CI, 1.10-1.50), diabetes mellitus (OR, 1.52; 95% CI, 1.07-2.16), and cerebrovascular disease (OR, 2.13; 95% CI, 1.11-4.09). Intraoperative factors were: cardiopulmonary bypass time (OR, 33.78; 95% CI, 23.15-44.41), aortic clamping time (OR, 13.24; 95% CI, 7.78-18.69), use of intra-aortic balloon pump (OR, 4.44; 95% CI, 2.37-8.30), and type of surgery (OR, 1.01; 95% CI, 0.43-2.39). Postoperative factors were: infection (OR, 3.58; 95% CI, 1.43-8.97), redo operation (OR, 2.57; 95% CI, 1.75-3.78), emergency surgery (OR, 4.76; 95% CI, 3.05-7.43), and low cardiac output (OR, 2.30; 95% CI, 1.05-5.04). CONCLUSIONS:Our results support that preoperative, intraoperative, and postoperative factors are associated with AKI-CS. Ejection fraction, BMI, acute myocardial infarction, type of surgery, and congestive heart failure were not absolutely associated with AKI.