Effect of Impedance-Guided Fluid Therapy on Treatment Outcomes of Patients with Heart Failure: A Systematic Review and Meta-Analysis

INTRODUCTION: Traditional volumetric assessment methods have limitations in the management of HF. The clinical value of impedance-guided monitoring (including bioelectrical impedance analysis [BIA], lung/thoracic impedance [LI], or intrathoracic impedance monitoring [IIM]) for quantifying extracellular fluid status remains controversial. This study aims to systematically evaluate the effect of impedance-guided fluid management on rehospitalization rates, mortality, and other outcomes in patients with HF. METHODS: PubMed, Embase, and Web of Science were searched from inception to May 31, 2025, for randomized controlled trials (RCTs) comparing impedance-guided fluid therapy with standard care in patients with HF. This review was conducted in accordance with the PRISMA guidelines. RESULTS: A total of 4 RCTs or secondary analyses of RCTs involving 650 patients with HF (impedance- guided group: 326 cases) were included. The risk of rehospitalization for HF was reduced without statistical significance in the impedance-guided group (OR: 0.73, 95% CI: 0.22- 2.48), while the risk of mortality for HF demonstrated a statistically significant reduction (OR: 0.33, 95% CI: 0.20-0.56), though these findings should be interpreted with caution given the limited number of included studies. The impedance-guided group demonstrated positive trends in reducing the incidence of acute kidney injury (AKI), lowering N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and improving quality of life. These outcomes were not subjected to analysis due to data heterogeneity. DISCUSSION: This meta-analysis suggests that impedance-guided fluid management did not demonstrate a statistically significant reduction in HF rehospitalization in the pooled analysis, though a consistent directional trend was observed. However, the statistics about HF-related mortality among patients with HF showed that impedance-guided fluid therapy potentially provided a tool for more precise volume management. Also, these findings are based on a limited number of studies with methodological heterogeneity. CONCLUSION: Impedance-guided fluid management may represent a potential adjunct for reducing rehospitalization in patients with HF. Given the methodological heterogeneity and small number of included studies in this research, future large-scale, high-quality RCTs are needed to confirm these results in clinical practice.