Background: Risk factors for postoperative acute kidney injury (AKI) are well described in nontransplantation
settings. Data regarding risks and consequences of AKI after cardiac transplantation are unclear. Methods: We
analyzed 756 cardiac transplant recipients between 1993 and 2004. The primary outcome is postoperative AKI
requiring dialysis therapy. Secondary outcomes are hospital mortality and postoperative morbidities, including
cardiac, neurological, and serious infection. Wilcoxon rank-sum, chi-square, or Fisher exact tests were used for
univariable comparison. A bootstrap-bagging procedure (1,000 repetitions) and multivariable logistic analysis with
multiple imputation were used for the final model. Results: AKI frequency was 5.8% (44 of 756 patients). By means of
univariable analysis, preoperative risk factors for AKI were diabetes, prior cardiac surgery, intra-aortic balloon
pump use, albumin level, creatinine level, clinical severity score, and cold ischemia time. Intraoperative risk factors
were cardiopulmonary bypass time and transfusion requirement. By means of multivariate analysis, serum
creatinine level (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.6 to 4.6), serum albumin level (OR, 0.34; 95% CI, 0.21 to 0.54), insulin-requiring diabetes (OR, 3.5; 95% CI, 1.4 to 9.0), and cardiopulmonary bypass time (OR, 1.29; 95% CI, 1.02 to 1.64) were independent predictors of postoperative AKI. The overall postoperative mortality rate was 4.2%; it was 50% in patients with AKI compared with 1.4% in patients without AKI. AKI was associated with greater
frequencies of cardiac, neurological, and serious infection morbidities (43.2%, 18.2%, and 54.6% versus 5.5%, 2.3%,
and 7.2%, respectively; P < 0.001). Conclusion: AKI is associated with significant morbidity and mortality after
cardiac transplantation. Predictors of AKI can be used to risk-stratify patients to ameliorate further kidney injury
and offer a survival benefit. Am J Kidney Dis 48:787-796.