Independent association between acute renal failure and mortality following cardiac surgery.
OBJECTIVE
To determine whether there is an independent association of acute renal failure requiring dialysis with operative mortality after cardiac surgery.


METHODS
The 42,773 patients who underwent coronary artery bypass or valvular heart surgery at 43 Department of Veterans Affairs Medical Centers between 1987 and 1994 were evaluated to determine the association between acute renal failure sufficient to require dialysis and operative mortality, with and without adjustment for comorbidity and postoperative complications. Crude and adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were derived from logistic regression analysis.


RESULTS
Acute renal failure occurred in 460 (1.1%) patients. Overall operative mortality was 63.7% in these patients, compared with 4.3% in patients without this complication. The unadjusted OR for death was 39 (95% CI 32 to 48). After adjustment for comorbid factors related to the development of acute renal failure (surgery type, baseline renal function, preoperative intraaortic balloon pump, prior heart surgery, NYHA class IV status, peripheral vascular disease, pulmonary rales, left ventricular ejection fraction below 35%, chronic obstructive pulmonary disease, systolic blood pressure, and the cross-product of systolic blood pressure and surgery type), the OR was 27 (95% CI 22 to 34). Further adjustment was made for seven postoperative complications (low cardiac output, cardiac arrest, perioperative myocardial infarction, prolonged mechanical ventilation, reoperation for bleeding or repeat cardiopulmonary bypass, stroke or coma, and mediastinitis), that were independently associated with operative mortality. The OR adjusted for comorbidity and postoperative complications associated with acute renal failure was 7.9 (95% CI 6 to 10).


CONCLUSIONS
Acute renal failure was independently associated with early mortality following cardiac surgery, even after adjustment for comorbidity and postoperative complications. Interventions to prevent or improve treatment of this condition are urgently needed.
Chertow
G M
GM
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Levy
E M
EM
Hammermeister
K E
KE
Grover
F
F
Daley
J
J
D058186:Acute Kidney Injury / Q000209:etiology / Q000401:mortality* / Q000628:therapy; D000368:Aged; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality*; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011183:Postoperative Complications / Q000401:mortality*; D006435:Renal Dialysis; D012307:Risk Factors