Biochemical Determinants of Changes in Plasma Volume After Decongestion Therapy for Worsening Heart Failure

Abstract

Optimal vascular volume is required to avoid organ dysfunction during decongestive therapy for worsening heart failure (HF). This study investigated the relation between changes in serum substance(s) and the vascular volume after diuresis in HF patients. Data from 47 patients with HF undergoing conventional diuretic therapy were analyzed. Blood tests included measurements of hemoglobin, hematocrit, and serum albumin/solutes. The relative changes in the plasma volume (%PV) from worsening HF to recovery were determined with the use of the Strauss formula. When divided into 2 groups based on the median %PV, the group with preserved volume (%PV ≥ -10%, range -10% to 21%; n = 23) exhibited a smaller decrease in body weight (-2.50 ± 1.98 vs -4.29 ± 2.60 kg; P = .012) and serum sodium (Na) (-1.57 ± 3.29 vs -4.13 ± 4.96 mEq/L; P = .04) and chloride (Cl) (-2.0 ± 4.06 vs -6.79 ± 5.21 mEq/L; P = .001) concentrations and a smaller increase in albumin (0.20 ± 0.28 vs 0.41 ± 0.24g/dL; P = .009) compared with the group with nonpreserved volume (%PV < -11%, range -33% to -11%; n = 24) after decongestive therapy. Changes in %PV were positively correlated with changes in body weight (r = 0.406; P = .0047) and serum Na (r = 0.433; P = .0024) and Cl (r = 0.408; P = .0044) concentrations and negatively correlated with changes in albumin (r = -0.492; P = .0004), blood urea nitrogen (r = -0.306; P = .037), and creatinine (r = -0.306; P = .036). Multivariate logistic regression analysis demonstrated an independent association between preserved %PV and an increased or preserved serum Cl concentration after decongestive therapy (odds ratio 8.71, 95% confidence interval 1.20-63.0; P = .032). Positive and independent association exists between change in the vascular volume and the serum Cl concentration under decongestive HF therapy.