Background
The effect of cardiac catheterization timing, contrast media dose, and preoperative renal function on post cardiac surgery acute renal failure (ARF) prevalence is unclear.
Methods and Results
Data of 395 consecutive patients who underwent CABG were prospectively collected. Glomerular filtration rate (eGFR) was estimated by the CockcroftGault equation. Patients were divided into 3 groups according to the time between cardiac catheterization and surgery (Group I:≤1 day, Group II:>1 and ≤5 days, Group III:>5 days). Patients who underwent salvage operation, or were on dialysis before surgery were excluded. Multivariable analysis was used to identify risk factors for ARF (defined as 25% decrease from baseline of eGFR, and eGFR≤60ml/min on postoperative day 3). propensity score analysis was used to adjust differences in preoperative characteristics between groups. ARF developed in 13% of patients. Hospital mortality was 3.3% and was higher in patients who developed ARF (21%) vs those that did not (0.6%, p<0.001). Multivariable analysis identified operation within 24 hours of catheterization (OR=4), and eGFR<60ml/min up to 5 days from catheterization (OR=2.5) as independent predictors of ARF (p<0.05). The use of more than 1.4 ml/kg of contrast media in patients with eGFR<60ml/min predicted ARF as well (OR=5, p<0.001). Older age, lower weight, and lower preoperative hemoglobin levels were also associated with ARF.
Conclusions
Whenever possible, cardiac surgery should be delayed for at least 24 hours (preferably 5 days) from catheterization, especially in patients with low eGFR, and in those who received high dose of contrast media.
Predictors of acute renal failure requiring renal replacement therapy post cardiac surgery in patients with preoperatively normal renal function
