Bioimpedance Indices of Fluid Overload and Cardiorenal Outcomes in Heart Failure and Chronic Kidney Disease: a Systematic Review

•Fluid overload by bioimpedance is associated with mortality in chronic kidney failure and heart failure.•Associations are also seen with cardiovascular outcomes driven by heart failure.•Significant heterogeneity exists in bioimpedance parameters and outcome definitions.•There is a potential role for bioimpedance as an intermediate clinical trial endpoint.•There is a need for consensus thresholds of fluid overload to maximize utility.