Prognostic Value of Red Blood Cell Distribution Width for Patients with Heart Failure: A Systematic Review and Meta-Analysis of Cohort Studies

Aims: Multiple studies have investigated the prognostic role of red blood cell distribution width (RDW) for patients with heart failure (HF), but the results have been inconsistent. The aim of the present study was to estimate the impact of RDW on the prognosis of HF by performing a systematic review and meta-analysis. Methods and Results: The Embase, PubMed, and Web of Science databases were searched up to November 16, 2013 to identify eligible cohort studies. The quality of each study was assessed using the Newcastle-Ottawa Scale (NOS). The association between RDW, either on admission or at discharge, and HF outcomes (all-cause mortality [ACM], heart transplantation, cardiovascular mortality, and rehospitalization, etc.) were reviewed. The overall hazard ratio (HR) for the effect of RDW on ACM was pooled using a random-effects model, and the publication bias was evaluated using funnel plots and Eggers' tests. Seventeen studies, with a total of 18288 HF patients, were included for systematic review. All eligible studies indicated that RDW on admission and RDW at discharge, as well as its change during treatment, were of prognostic significance for HF patients. The HR for the effect of a 1% increase in baseline RDW on ACM was 1.10 (95% confidence interval: 1.07-1.13), based on pooling of nine studies that provided related data. However, publication bias was observed among these studies. Conclusions: HF patients with higher RDW may have poorer prognosis than those with lower RDW. Further studies are needed to explore the potential mechanisms underlying this association.