Impact of renal dysfunction on outcomes of coronary artery bypass surgery: results from the Society of Thoracic Surgeons National Adult Cardiac Database.
BACKGROUND
Although patients with end-stage renal disease are known to be at high risk for mortality after coronary artery bypass graft (CABG) surgery, the impact of lesser degrees of renal impairment has not been well studied. The purpose of this study was to compare outcomes in patients undergoing CABG with a range from normal renal function to dependence on dialysis.


RESULTS
We reviewed 483,914 patients receiving isolated CABG from July 2000 to December 2003, using the Society of Thoracic Surgeons National Adult Cardiac Database. Glomerular filtration rate (GFR) was estimated for patients with the use of the Modification of Diet in Renal Disease study formula. Multivariable logistic regression was used to determine the association of GFR with operative mortality and morbidities (stroke, reoperation, deep sternal infection, ventilation >48 hours, postoperative stay >2 weeks) after adjustment for 27 other known clinical risk factors. Preoperative renal dysfunction (RD) was common among CABG patients, with 51% having mild RD (GFR 60 to 90 mL/min per 1.73 m2, excludes dialysis), 24% moderate RD (GFR 30 to 59 mL/min per 1.73 m2, excludes dialysis), 2% severe RD (GFR <30 mL/min per 1.73 m2, excludes dialysis), and 1.5% requiring dialysis. Operative mortality rose inversely with declining renal function, from 1.3% for those with normal renal function to 9.3% for patients with severe RD not on dialysis and 9.0% for those who were dialysis dependent. After adjustment for other covariates, preoperative GFR was one of the most powerful predictors of operative mortality and morbidities.


CONCLUSIONS
Preoperative RD is common in the CABG population and carries important prognostic importance. Assessment of preoperative renal function should be incorporated into clinical risk assessment and prediction models.
Cooper
William A
WA
Division of Cardiothoracic Surgery, Joseph B. Whitehead Department of Surgery, Carlyle Fraser Heart Center, Emory University School of Medicine, Atlanta, GA, USA.
O'Brien
Sean M
SM
Thourani
Vinod H
VH
Guyton
Robert A
RA
Bridges
Charles R
CR
Szczech
Lynda A
LA
Petersen
Rebecca
R
Peterson
Eric D
ED
D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality*; D003324:Coronary Artery Disease / Q000150:complications* / Q000401:mortality / Q000601:surgery; D003327:Coronary Disease / Q000150:complications / Q000601:surgery; D016208:Databases, Factual; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D009017:Morbidity; D009026:Mortality; D011183:Postoperative Complications / Q000209:etiology; D011237:Predictive Value of Tests; D011379:Prognosis; D012044:Regression Analysis; D018570:Risk Assessment; D016896:Treatment Outcome