Unraveling the Role of RDW in Predicting Early and Long-term Mortality following CABG Surgery.

Background: Red Cell Distribution Width (RDW) is a commonly used biomarker that assesses the variation in erythrocyte volume. Higher RDW levels are associated with conditions such as absolute iron deficiency, inflammation-induced iron sequestration, ischemia, and oxidative stress. These factors can contribute to unfavorable outcomes following cardiac surgery. While previous studies have explored the prognostic value of elevated RDW as a predictor of increased early and late mortality after Coronary Artery Bypass Grafting (CABG), it remains understudied in large-scale series within Turkey. Therefore, the objective of our research is to examine the predictive capability of RDW in relation to early and late-term mortality subsequent to CABG surgery. Metod: This study included all 1867 patients who underwent isolated Coronary Artery Bypass Grafting (CABG) surgery at our hospital between July 2011 and August 2013. The mean age of the patients was 60.4 ± 10.1 years (59.8 ± 9.9 years for males and 62.4 ± 10.7 years for females). Among the patients, 22.2% (n=414) were female. Early mortality was defined as deaths occurring within the first 30 days of hospitalization or within the hospital premises. Long-term mortality data were obtained through the mortality reporting system. The mean follow-up duration was 116.1 ± 6.8 months. Early mortality rate was 3.9% and the long-term mortality rate was determined as 29.6%. Mortality data were reevaluated based on patients preoperative RDW levels. Results: The overall mortality rate observed in this study was 32.4% (n=604), with an early mortality rate of 3.9% (n=72). The median RDW value for all patients was 14.8% (14.1-15.8). Significantly higher median RDW levels were observed in the subgroup of patients who experienced early mortality compared to those who survived (15.4% vs 14.8%, p<0.05). To further investigate the relationship between RDW and mortality, the remaining patients were stratified into three groups based on preoperative RDW values: Group 1 (0-25th percentile), Group 2 (25-75th percentile), and Group 3 (>75th percentile). During the ten-year follow-up period, the survival rates were 74.7%, 72.3%, and 61.2% respectively for each group. Patients in Group 3 demonstrated significantly lower survival rates compared to the other groups (Table 1), indicating a long-term impact of elevated RDW levels on mortality (p<0.001). Univariate analysis revealed a statistically significant association between RDW levels and mortality prediction (p: 0.000; OR: 1.166 CI: 1.096-1.239). Conlcusion: Elevated RDW levels may be considered as a predictor for both early and late mortality following coronary artery bypass grafting (CABG) in the Turkish population too. However, the significance of normalizing RDW values during the preoperative period and its impact on mortality remains unknown, necessitating further extensive studies to elucidate this relationship. [ABSTRACT FROM AUTHOR]