By Diagnostics World Staff
August 22, 2018 | The publication of an investigator-initiated study from Duke University and The Mayo Clinic demonstrated that despite the widespread use of formula-derived estimates of plasma volume in heart failure patients, these methods are inaccurate compared to measured volume using the Daxor’s BVA-100 blood volume measurement diagnostic. The study, “Calculated Estimates of Plasma Volume in Patients with Chronic Heart Failure – Comparison to Measured Volumes” was recently published in the Journal of Cardiac Failure.
“This study shows that indirect assessments of plasma volume or blood volume are limited by their inaccuracy. Our study shows that this is true for formula based volume assessment or the measure of hemoconcentration and similarly poor correlation has previously been shown for the physical exam and even intra-cardiac pressure assessments,” Marat Fudim, Fellow, Division of Cardiology, Duke University and one of the study authors, said in a press release.
In the study, plasma volume was measured using Daxor’s BVA-100 in 110 patients with clinically stable chronic heart failure. These measurements were correlated using two different plasma volume estimation techniques. The first was the Kaplan-Hakim formula, which calculates blood volume using a formula calculating hematocrit relative to dry body weight. The second, the Strauss formula, estimates changes in plasma volume over time using hemoglobin and hematocrit measurement. The study ultimately showed neither formula demonstrated an accurate blood volume estimate compared to the BVA-100. These formulas varied in their accuracy between just 16 and 68% compared to Daxor’s BVA-100, the acknowledged ‘gold-standard’ of volume measurement.
“This study is further evidence showing why BVA-guided treatment of heart failure leads to significantly better results in mortality and readmission. Proxy measures such as formulas, hemodynamics, and clinical assessment alone do not allow the individualization of care needed for optimal treatment of HF. Based on these results, we continue to work to educate physicians about direct blood volume measurement and to expand the availability of the BVA-100 across the US,” said Jonathan Feldschuh, Daxor’s chief technology officer, in an official statement.