Predictive Value of Red Blood Cell Distribution Width for 1-Year All-Cause Mortality in Critically Ill 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 AMI. Significant prognostic value of 24h dRDW was found in AMI patients with anemia, but not in those without anemia.