Predictive Value of Red Blood Cell Distribution Width for 1-Year All-Cause Mortality in Critically III Patients with Acute Myocardial Infarction

Objective: Red blood cell distribution width (RDW) on admission is a prognostic factor in cardiovascular disease. This study investigated the prognostic value of the RDW measured within 24 hours before discharge (24h dRDW) on 1-year all-cause mortality in critically ill patients with acute myocardial infarction (AMI), and compared the effect of 24h dRDW in anemia and non-anemia patients. Materials and Methods: Altogether, 4088 patients with AMI were studied retrospectively. Data from the MIMIC-III database were collected and analyzed. The Kaplan-Meier method, Cox regression models, and receiver operating characteristic (ROC) analysis were used to assess the impact of 24h dRDW on all-cause mortality in AMI patients, and a stratified analysis was performed to investigate the prognostic value of 24h dRDW in anemia and non-anemia patients. Results: Of the 4088 patients, there were 704 non-survivors (17.2%). The non-survivors had a higher RDW than the survivors (p<0.001). Cox regression analysis showed that 24h dRDW had a significant independent association with 1-year all-cause mortality in critically ill patients with AMI (quintile 5 vs quintile 1, HR, 95% CI: 2.847, 2.014-4.023). The area under the ROC curve of 24h dRDW was 0.710 (95% CI, 0.689-0.730). In the stratified analysis, a significant prognostic value of 24h dRDW was found in anemia patients for 1-year all-cause mortality, but not in non-anemia patients. Conclusion: Elevated 24h dRDW values are significantly associated with increased hazards of all-cause mortality in critically ill patients with AMT. Significant prognostic value of 24h dRDW was found in AMI patients with anemia, but not in those without anemia.