Association between the red blood cell distribution width-to-platelet ratio and the risk of congestive heart failure in critically ill patients with ischemic stroke: a retrospective cohort study based on the MIMIC-IV database

This study aimed to investigate the association between the red blood cell distribution width-to-platelet ratio (RPR) and the risk of congestive heart failure (CHF) in critically ill patients with ischemic stroke (IS), attempting to provide further evidence regarding the brain-heart axis (BHA). Data from 1,657 critically ill patients with IS were extracted from the Medical Information Mart for Intensive Care IV database for analysis. Kaplan-Meier survival curves were applied for the comparison of in-hospital mortality across groups. Cumulative incidence curves were used to assess the impact of the RPR on the occurrence of CHF. Association between the RPR and the risk of CHF was analyzed using the multifactorial Cox regression model, restricted cubic splines (RCS), and receiver operating characteristic curve analysis. Furthermore, multifactorial Cox regression analyses were performed to investigate the association of the RPR with CHF risk as well as in-hospital mortality across different subgroups. Among the 1,657 critically ill patients with IS (mean age: 72 years), Kaplan-Meier and cumulative incidence curves suggested that a lower RPR was significantly associated with a lower CHF risk and a better prognosis ( P < 0.05). In the multifactorial Cox regression analysis (model III), patients in the highest RPR quartile (Q4) exhibited the highest risk of CHF (hazard ratio [HR]: 1.47, 95% confidence interval [CI]: 1.01–2.14, p < 0.05), whereas those in the lowest RPR quartile (Q1) had the lowest risk of CHF, with intermediate risks observed in Q2 and Q3. RCS analysis further suggested a positive association between the RPR and CHF risk. In this retrospective cohort, a higher RPR was independently associated with an increased risk of CHF and with in-hospital mortality in critically ill patients with IS. The RPR may serve as a potential marker for CHF risk stratification in this population; however, given the observational design, these findings are hypothesis-generating, and any proposed link between the RPR and BHA-related mechanisms should be regarded as a hypothesis that requires validation in prospective and mechanistic studies.