Effect of unfractionated sodium heparin at therapeutic doses on the hemorheological parameters of patients with deep vein thrombosis

We studied 25 patients with DVT in basal conditions and after 24 h of treatment with unfractionated heparin (UFH) to discover the possible effect of therapeutic doses of this drug on hemorheological parameters in these patients. The parameters studied are: erythrocyte aggregation (EA) at stasis (EA_○) and a low shear rate (EA₁), blood viscosity, plasma viscosity, fibrinogen and activated partial thromboplastin time. The results show that UFH significantly improves EA_○ and EA₁, from 4.87 and 9.73 without heparin to 3.53 and 8.70 with heparin respectively. The other hemorheological characteristics are not significantly modified. We conclude that UFH at therapeutic doses seems to improve erythrocyte aggregability regardless of the plasma level of fibrinogen. This suggests a possible direct effect of UFH on EA.