Risks and outcomes of acute kidney injury requiring dialysis after cardiac transplantation.
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).


CONCLUSIONS
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.
Boyle
Janet M
JM
Department of Nephrology and Hypertension, Cleveland Clinic Foundation, Cleveland, OH, USA.
Moualla
Soundous
S
Arrigain
Susana
S
Worley
Sarah
S
Bakri
Mohamed H
MH
Starling
Randall C
RC
Heyka
Robert
R
Thakar
Charuhas V
CV
D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000401:mortality / Q000628:therapy; D000328:Adult; D002315:Cardiopulmonary Bypass; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D003404:Creatinine / Q000097:blood; D003920:Diabetes Mellitus / Q000453:epidemiology; D003956:Dialysis; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D016027:Heart Transplantation / Q000009:adverse effects*; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D009017:Morbidity; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000453:epidemiology; D016491:Peripheral Vascular Diseases / Q000453:epidemiology; D011183:Postoperative Complications / Q000453:epidemiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
D003404:Creatinine