Daxor Corporation announces that a second research report derived from a study using the Daxor Blood Volume Analyzer (BVA-100) was presented at the annual Heart Failure Society of America (HFSA) conference in San Diego.

 The BVA-100 enables measurement of whole blood volume, including plasma volume and red blood cell volume. 

Serum B-Natriuretic Peptide (BNP) levels are often used as a surrogate measure to estimate the degree of fluid retention in heart failure patients. When BNP levels are high, physicians assume that the heart failure patients suffer from volume overload and are likely to prescribe diuretics to promote fluid excretion.

 However, BNP is released by ventricular myocytes in response to cardiac stretch, which can occur for reasons other than fluid overload. In fact, the manufacturer of BNP testing equipment makes no claim that BNP is a surrogate for direct blood volume measurement. If BNP is not an accurate surrogate for blood volume, it may cause physicians to inappropriately prescribe diuretics, which could result in damage to patients’ kidneys. John E. Strobeck, MD, PhD, and colleagues from the Valley Hospital examined whether or not there is a correlation between BNP levels and blood volume in a series of heart failure patients. An abstract which described their findings was published in the August 2010 Supplement (Volume 16, Issue 8) of the Journal of Cardiac Failure. The complete poster presentation is available on Daxor’s website at www.daxor.com/hfsa2010.asp.

Dr. Strobeck’s study, titled "Lack of Correlation Between I-131 Labeled Albumin Measurements of Blood Volume and Serum B-Natriuretic Peptide Levels in Heart Failure Patients," assessed blood volume and BNP levels in 151 heart failure patients. The results showed that there is no significant correlation between serum BNP levels and total blood volume, not even when the data was analyzed based on age or gender. Previous, smaller studies have found a similar lack of correlation between BNP levels and blood volume in a variety of patient types. 

However, the current study represents the largest study to date to assess this correlation using actual direct blood volume measurement. In addition, this study found that over 60% of this heart failure patient population was anemic based on their red blood cell volumes. These findings provide evidence for the benefits of blood volume measurements in conjunction with clinical assessment to guide diuretic therapy, or other forms of renal replacement therapy, in heart failure patients.

Source: Daxor Corp