The Effect of Mild Preoperative Renal Impairment on Early Postoperative Mortality after Open Cardiac Surgery

  • A Ghani
  • E Shawaf
  • L Vislocky
Keywords: cardiac surgery, chronic kidney disease, renal impairment, mortality


Introduction: Severe preoperative renal impairment (RI) is often included in score systems used to predict outcome after open cardiac surgery. The purpose of this study was to investigate the impact of mild preoperative RI on the early postoperative mortality after open heart surgery. Methods: We retrospectively collected data of all patients who underwent open cardiac surgery in Kuwait Chest Disease Hospital from January 2005 to June 2006. Multiple baseline and perioperative variables, including the presence of mild preoperative RI, were scrutinized for potential association with early post operative mortality. Results: The study included 500 subjects, 47 of whom had mild preoperative RI, defined by an estimated glomerular filtration rate (eGFR) between 89-60 ml/min. The overall 30 days mortality was 6.8%. Mortality was 40.8% in patients who had mild preoperative RI, 28.7% in patients who developed acute postoperative deterioration in renal function and 33.3% in patients who required dialysis postoperatively. Binary logistic regression analysis showed that the development of postoperative multi-organ failure (MOF), female gender and mild preoperative RI were the only independent variables predicting early post operative mortality after cardiac surgeries. Conclusion: A number of studies have identified moderate to severe RI as a predictor of mortality and morbidity after open heart surgery. RI is often associated with other comorbidities which are likely to have a negative impact on morbidity and mortality after open heart surgery. However, in this study mild preoperative RI remained a strong predictor of early mortality even after adjustment for several confounders. Keywords: cardiac surgery, chronic kidney disease, renal impairment, mortality

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eISSN: 1858-554X
print ISSN: 1858-554X