Related Experiment Videos
Coronary artery bypass grafting in non-dialysis-dependent mild-to-moderate renal dysfunction
A Weerasinghe1, P Hornick, P Smith
1Department of Cardiothoracic Surgery, Imperial College School of Medicine, University of London, Hammersmith Hospital, London W12 0HS, United Kingdom. aweerasinghe@ic.ac.uk
Insights
Mildly elevated preoperative serum creatinine levels significantly increase the risk of complications and mortality following coronary artery bypass grafting (CABG). Higher creatinine levels correlate with greater need for renal support and longer hospital stays.
Area of Science:
- Cardiology
- Nephrology
- Surgical Outcomes
Background:
- Preoperative serum creatinine levels are a known risk factor in cardiac surgery.
- The impact of mild-to-moderate elevations in preoperative serum creatinine on morbidity and mortality after coronary artery bypass grafting (CABG) requires further investigation in large-scale studies.
- Understanding these effects is crucial for optimizing patient care and surgical planning.
Purpose of the Study:
- To evaluate the association between mild-to-moderate preoperative serum creatinine elevations and postoperative outcomes in CABG patients.
- To identify patient-specific variables that contribute to increased serum creatinine levels following CABG.
- To assess the need for mechanical renal support, duration of special care and hospital stay, complication rates, and in-hospital mortality.
Main Methods:
- A cohort of 1427 patients undergoing first-time CABG with cardiopulmonary bypass were analyzed.
- Patients were stratified into three groups based on preoperative serum creatinine levels: <130 µmol/L, 130-149 µmol/L, and ≥150 µmol/L.
- Multivariable stepwise logistic regression analysis was employed to identify significant predictors of outcomes.
Main Results:
- Elevated preoperative serum creatinine (≥130 µmol/L) significantly increased the likelihood of requiring mechanical renal support, extended special care, and prolonged total hospital stay (P<.001).
- In-hospital mortality showed a significant increase with creatinine levels of 130-149 µmol/L (P=.045) and ≥150 µmol/L (P<.001).
- Hypertension, advanced angina class, nonelective surgery, and prolonged cardiopulmonary bypass time were associated with increased postoperative serum creatinine levels.
Conclusions:
- Even mild elevations (130-149 µmol/L) in preoperative serum creatinine significantly elevate the risk of mechanical renal support, prolonged hospital stays, and in-hospital mortality after CABG.
- Higher preoperative creatinine levels (≥150 µmol/L) result in more pronounced adverse effects.
- The method of myocardial protection (cardioplegia vs. crossclamp fibrillation) did not significantly impact the studied outcomes.
Objectives:
The effect of mild-to-moderate elevation of preoperative serum creatinine levels on morbidity and mortality from coronary artery bypass grafting has not been investigated in a large multivariable model incorporating preoperative and intraoperative variables. Our first objective was to ascertain the effect of a mild-to-moderate elevation in the preoperative serum creatinine level on the need for mechanical renal support; the duration of special care and total postoperative stay; the occurrence of infective, respiratory, and neurologic complications; and hospital mortality. Our second objective was to ascertain which patient variables contributed to an increase in the serum creatinine level in association with coronary artery bypass grafting.
Methods:
A total of 1427 patients who had no known pre-existing renal disease and who were undergoing first-time coronary artery bypass grafting with cardiopulmonary bypass were recruited for the study. Patients were divided, on the basis of preoperative serum creatinine level, into 3 groups as follows: creatinine level of less than 130 micromol. L(-1); creatinine level of 130 to 149 micromol. L(-1); and creatinine level of 150 micromol. L(-1) or greater. A multivariable stepwise logistic regression analysis was used, and variables significant at the 5% level were included when developing the final multivariable models.
Results:
Multivariable analysis showed that elevation of the preoperative serum creatinine level to 130 micromol. L(-1) or greater increased the likelihood of needing mechanical renal support postoperatively (P <.001), as well as the need for postoperative special care (P <.001) and total hospital stay (P <.001). In-hospital mortality was also significantly elevated as the preoperative creatinine level rose to 130 to 149 micromol. L(-1) (P =.045) and to 150 micromol. L(-1) or greater (P <.001). It was further observed that patients with preoperative serum creatinine levels of 130 to 149 micromol. L(-1) (P =.02), patients with preoperative serum creatinine levels of 150 micromol. L(-1) or greater (P =.001), hypertensive patients (P =.007), patients with angina of New York Heart Association class III or greater (P =.001), patients having a nonelective operation (P =.002), and patients having a prolonged cardiopulmonary bypass time (P =.008) had a significantly greater increase in the serum creatinine level as a result of coronary artery bypass grafting. Of particular note was the finding that the method of myocardial protection (cardioplegia or crossclamp fibrillation) did not significantly influence in-hospital mortality, need for mechanical renal support, or special care or total postoperative hospital stay.
Conclusions:
A mild elevation (130-149 micromol. L(-1)) in the preoperative serum creatinine level significantly increases the need for mechanical renal support, the duration of special care and total postoperative stay, and the in-hospital mortality. As the preoperative serum creatinine level increases further (> or =150 micromol. L(-1)), this effect is more pronounced. No significant difference in outcome was observed between the use of cardioplegia or crossclamp fibrillation for myocardial protection.