Association of the red cell distribution width/albumin ratio with 6-month readmission risk in heart failure patients

Abstract

Readmission due to heart failure (HF) remains a major clinical and economic challenge. The red cell distribution width-to-albumin ratio (RAR) has been proposed as a novel biomarker reflecting chronic inflammation, nutritional status, and multi-organ involvement in cardiovascular diseases. However, the association between RAR and readmission risk, particularly in Asian populations with HF, remains unclear. This study aimed to evaluate the relationship between RAR levels and the 6-month readmission risk among Chinese patients with heart failure. We conducted a retrospective cohort study using data from the Zigong Heart Failure Database, which included 2008 patients hospitalized for HF between December 2016 and June 2019. After excluding patients with missing RDW, albumin, or readmission data, 1854 patients were included in the final analytical cohort. Based on RAR values, patients were divided into four quartiles. Multivariable Cox proportional hazards regression models were used to assess the association between RAR and 6-month readmission risk, adjusting for demographics, clinical parameters, comorbidities, and medications. Subgroup analyses were performed to examine the consistency of associations across different patient characteristics. The overall 6-month readmission rate was 38.5% (714/1854). Patients in higher RAR quartiles had a significantly greater risk of readmission than those in lower quartiles ( P  = 0.0025). In unadjusted analyses, each unit increase in RAR was associated with a 57% higher risk of 6-month readmission (HR 1.57, 95% CI: 1.27–1.93, P  < 0.001). This association remained significant after adjusting for confounding variables (HR 1.52, 95% CI: 1.21–1.92, P  < 0.001). After full adjustment, patients in the highest quartile (Q4) had a 39% higher risk of readmission compared with those in the lowest quartile (Q1) (HR 1.39, 95% CI: 1.10–1.76, P  < 0.001). Subgroup analyses showed consistent associations across sex, age, BMI, NYHA classification, and medication use, with no significant interactions observed. Elevated RAR was independently associated with an increased 6-month readmission risk among Chinese patients with HF. As a simple and cost-effective biomarker, RAR may enhance risk stratification and inform clinical decision-making in HF management, potentially improving patient outcomes and reducing healthcare burden.