Predictors of renal replacement therapy following isolated coronary artery surgery – a retrospective case controlled study

Objectives: Severe acute kidney injury (AKI) requiring postoperative renal replacement therapy (RRT) is associated with increased morbidity and mortality rates following cardiac surgery. Our study aimed to analyze patients requiring postoperative RRT in a population undergoing isolated coronary artery surgery. Methods: Following exclusions, we analyzed 124 944 consecutive patients in the Polish National Registry of Cardiac Surgical Procedures (KROK Registry), scheduled for isolated coronary artery surgery between January 2010 and December 2019. Patients who underwent preoperative chronic dialysis were excluded from the study. Data of patients requiring postoperative RRT and patients without postoperative RRT were compared. Results: In the analyzed population, 1668 patients (1.3%) developed AKI requiring RRT. In-hospital mortality among patients with and without postoperative RRT was 40.1 and 1.6%, respectively ( P <0.001). Patients requiring postoperative RRT had significantly more preoperative co-morbidities and more frequent postoperative complications. Preoperative chronic renal failure and cardiogenic shock were the two most prominent independent risk factors for postoperative RRT in these patients (OR: 5.0, 95% CI: 3.9–6.4, P <0.001 and OR: 3.9, 95% CI: 2.8–5.6, P <0.001, respectively). Conclusion: Severe AKI requiring postoperative RRT dramatically increases in-hospital mortality and is associated with the development of serious postoperative complications. The need for postoperative RRT is clearly associated with the presence of preoperative co-morbidities. Preoperative chronic renal failure and cardiogenic shock were particularly related to the development of this complication.