Association between Elevated Red Cell Distribution Width and Acute Kidney Injury after Open-Heart Surgery

Background: Acute kidney injury (AKI) is a major complication following cardiac surgery. Red Cell Distribution Width (RDW) has emerged as a prognostic marker in critical illness. This study evaluated the association between preoperative RDW and postoperative AKI after open-heart surgery. Materials and Methods: A retrospective observational study of 296 patients undergoing cardiac surgery with cardiopulmonary bypass was conducted. AKI was classified according to Kidney Disease: Improving Global Outcomes (KIDIGO) Criteria. Multivariable logistic regression and receiver operator characteristic analysis were used to evaluate RDW as a predictor of AKI. Results: AKI occurred in 26.7% of patients. Elevated preoperative RDW was independently associated with AKI. The discriminatory performance of RDW was limited (area under the curve: = 0.62), with a sensitivity of 54% and specificity of 70% at an optimal cutoff value of 14.1%. AKI was associated with significantly higher mortality. Conclusion: Elevated preoperative RDW is independently associated with AKI after cardiac surgery and may assist in perioperative risk stratification.