Renal failure after cardiac surgery: timing of cardiac catheterization and other perioperative risk factors.

Background: The incidence of acute renal failure after cardiac surgery remains high, and the ability to predict renal failure using well-defined baseline risk factors is important. The relationship between the timing of preoperative cardiac catheterization and the incidence of postoperative renal failure has not been previously described.

Methods: Perioperative variables for 649 patients over 12 months were prospectively collected. Variables included medical comorbidities, preoperative glomerular filtration rate calculated using the simplified Modification of Diet in Renal Disease equation, and date of cardiac catheterization. Endpoints were (A) renal failure defined as a rise in serum creatinine greater than 25% by the third postoperative day or renal dysfunction requiring the initiation of dialysis, and (B) hospital mortality.

Results: The incidence of renal failure and renal failure requiring dialysis were 24.0% and 4.2%, respectively. After multivariate analysis, age, cardiopulmonary bypass time, baseline glomerular filtration rate less than 60 mL/min (odds ratio [OR] 1.69; 95% confidence interval [CI]: 1.09 to 2.62; p = 0.047), and cardiac catheterization performed within 5 days before operation (OR 1.82; 95% CI: 1.17 to 2.84; p = 0.010) were independently associated with acute renal failure. Developing postoperative renal failure was independently related to hospital mortality (OR 3.70; 95% CI: 1.59 to 9.09; p = 0.003).

Conclusions: Cardiac catheterization performed within 5 days before operation, baseline glomerular filtration rate less than 60 mL/min, and prolonged cardiopulmonary bypass duration are significant risk factors for acute renal failure after cardiac surgery. Acute renal failure after cardiac surgery is a significant predictor of hospital mortality.