Red Blood Cell Distribution Width to Albumin Ratio for Predicting Type I Cardiorenal Syndrome in Patients with Acute Myocardial Infarction: A Retrospective Cohort Study

Red blood cell distribution width to albumin ratio (RAR) is a novel inflammatory biomarker that independently predicts adverse cardiovascular events and acute kidney injury. This study aimed to assess the predictive value of RAR for cardio-renal syndrome type I (CRS-I) risk in acute myocardial infarction (AMI) patients. This study retrospectively enrolled 551 patients who were definitively diagnosed as AMI between October 2021 and October 2022 at the Affiliated Zhongda Hospital of Southeast University. Participants were divided into two and four groups based on the occurrence of CRS-I and the quartiles of RAR, respectively. Demographic data, laboratory findings, coronary angiography data, and drug utilization were compared among the groups. Logistic regression and receiver operating characteristic curve (ROC) analysis were performed to identify independent risk factors for CRS-I and evaluated the predictive value of RAR for CRS-I. Among the cohort of 551 patients, 103 (18.7%) developed CRS-I. Patients with CRS-I exhibited significantly elevated RAR levels compared to those without the condition, and the incidence of CRS-I correlated with escalating RAR. Univariate and multivariate logistic regression analyses identified RAR as an independent risk factor for CRS-I. ROC curves analysis demonstrated that RAR alone predicted CRS-I with an area under the curve (AUC) of 0.683 (95% CI=0.642-0.741), which was superior to the traditional inflammatory marker C-reactive protein (CRP). Adding the variable RAR to the model for predicting the risk of CRS-I further improved the predictive value of the model from 0.808 (95% CI=0.781-0.834) to 0.825 (95% CI=0.799-0.850). RAR is an independent risk factor for CRS-I, and high levels of RAR are associated with an increased incidence of CRS-I in patients with AMI. RAR emerges as a valuable and readily accessible inflammatory biomarker that may play a pivotal role in risk stratification in clinical practice.