Predicting postoperative renal failure requiring dialysis, and an analysis of long-term outcome in patients undergoing valve surgery.
OBJECTIVE
Previous studies have been unable to identify independent valve-related risk factors for the occurrence of renal failure requiring dialysis (RF-D) in patients undergoing valve surgery. The study aim was to determine the incidence and predictors of renal failure in these patients, and to create a model based on these risk factors that could serve as a tool to predict this complication.


METHODS
Between January 1998 and December 2006, a total of 2,690 consecutive patients (1,546 males, 1,144 females; mean age 64 +/- 15 years) underwent valve or combined valve/coronary artery bypass graft (CABG) surgery at the authors' institution. The main outcome investigated was postoperative RF-D; other postoperative parameters investigated included hospital mortality, major morbidity, length of hospital stay, discharge condition and late survival.


RESULTS
RF-D occurred in 70 patients (2.6%). Multivariate analysis revealed preoperative renal failure (creatinine >2.5 mg/dl) (OR = 4.3), endocarditis (OR = 3.0), congestive heart failure (OR = 2.4), reoperation (OR = 2.3), diabetes (OR = 3.1) and cardiopulmonary bypass time >180 min (OR = 1.7) as independent predictors for postoperative RF-D. Hospital mortality among patients with RF-D was 50% (n = 35) compared to a mortality rate of 3.2% (n = 87) in patients without this complication (p <0.001). The long-term survival of discharged patients with RF-D was significantly decreased compared to those without RF-D. A logistic equation which included the coefficients of the regression analysis was generated to calculate an individual patient's risk for the development of renal failure. The predictive accuracy of the model and validation was measured (ROC area under the curve = 0.750).


CONCLUSIONS
Renal failure requiring dialysis is a well-known complication, particularly in patients undergoing complex valve operations, such as surgery for endocarditis and double-valve procedures. The poor long-term survival of patients with RF-D underlines the need to direct more resources towards the prevention and treatment of this complication in valve surgery patients.
Rahmanian
Parwis B
PB
Department of Cardiothoracic Surgery, Mount Sinai School of Medicine, New York, New York 10029-1028, USA.
Filsoufi
Farzan
F
Castillo
Javier G
JG
Zaku
Bledi
B
Chikwe
Joanna
J
Carpentier
Alain
A
Adams
David H
DH
D001026:Coronary Artery Bypass; D003920:Diabetes Mellitus / Q000453:epidemiology; D004696:Endocarditis / Q000453:epidemiology; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015999:Multivariate Analysis; D009518:New York / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D011183:Postoperative Complications; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D012086:Reoperation; D018570:Risk Assessment; D013997:Time Factors