Venous Hematocrit: Caveats to Informing Blood Volume and Relative Risk in Chronic Heart Failure

VHcts lack capacity to discriminate absolute BVs or the variability in RBC mass and plasma volume profiles above or below cut points. Therefore, quantitative BV measurements are key to adding specificity to individual vHct values, which permits reliable identification of BV status, assignment of appropriate risk, and guidance in management.