Plasma clearance of polyfructosan and extracellular body fluid distribution in idiopathic dilated cardiomyopathy and after heart transplantation

The total extracellular fluid volume and distribution in plasma and interst itial spaces, and the microvascular permeability properties were studied in 16 nonedematous patients with congestive heart failure (CHF) due to idiopa thic dilated cardiomyopathy and 17 such patients who underwent heart transp lantation (HT) by analyzing the 3-hour plasma disappearance curve of polyfr uctosan. Eighteen healthy subjects served as controls. Polyfructosan (3.5 k D) is an extracellular marker and inulin analog transported almost solely b y diffusion. The initial capillary membrane plasma clearance (i.e., the per meability-surface area product), the interstitial plasma clearance determin ed at 10 minutes (clearance[10]), and the extracellular volume were determi ned from the poly fructosan curves. I-131-albumin was used as a plasma volu me reference. Permeability-surface area product was elevated in both patien t groups (6.6 +/- 1.9 ml/kg/min in the CHF group and 6.7 +/- 2.0 ml/kg/min in the HT group vs 5.1 +/- 1.3 ml/kg/min in controls, p <0.01 for both), wh ereas clearance(10) was normalized in the HT group (4.5 +/- 0.9 ml/kg/min i n the HT group, 4.4 +/- 0.7 ml/kg/min in controls vs 5.0 +/- 0.9 ml/kg/min in the CHF group, p <0.1 and p <0.05, respectively), The normalization of i nterstitial plasma clearance of polyfructosan was associated with time sinc e HT (r = 0.49, p <0.05). Plasma volumes were similar in all 3 groups (41 /- 8 ml/kg in controls, 44 +/- 13 in the CHF group and 39 +/- 8 in the HT g roup). In contrast, total extracellular volume was elevated in both patient s groups (177 +/- 27 ml/kg in the CHF group and 173 +/- 27 in the HT group vs 152 +/- 12 in controls, p <0.01), The results strongly suggest a microva scular permeability defect in both patient groups that perhaps plays a role in the extravascular distribution of the excess extracellular fluid volume . (C)2000 by Excerpta Medico, Inc.