Different effects of enoxaparin and unfractionated heparin on some thrombogenesis markers during hemodialysis: a cross-over study.

BACKGROUND: Unfractionated heparin (UFH) and low molecular weight heparin constitute fundamental anticoagulants during hemodialysis (HD). We aimed to investigate the effect of UFH and enoxaparin on plasma levels of prothrombin fragment 1+2 (PF 1+2) and thrombin/antithrombin complex (TAT) as markers of intravascular thrombogenesis during HD.

METHODS: We enrolled 22 chronic HD patients, who were randomly assigned to either iv enoxaparin (n=11) or UFH (n=11) anticoagulation, and followed prospectively for 12 weeks before crossing over to the alternate therapy for further 12 weeks. Plasma levels of PF 1+2 and TAT were measured by immunoassay at the start, at 10 and 180 min of HD session after each period of evaluation.

RESULTS: The baseline PF 1+2 and TAT levels were comparable under enoxaparin and UFH treatment. PF 1+2 significantly decreased during both UFH (chi(2) ANOVA=9.82, P=0.007) and enoxaparin (chi(2) ANOVA=29.40, P<10(-6)) anticoagulated HD, while over-HD TAT levels changes differed depending on the type of heparin. The switch from enoxaparin to UFH treatment was connected with a significantly higher PF 1+2 after 10 and 180 min as well as higher TAT concentration after 180 min of HD. Only during enoxaparin anticoagulated HD 34% PF 1+2 decrease and TAT levels after 180 min of HD was closely associated with heparin dosage.

CONCLUSION: Single bolus of enoxaparin ensures efficient and convenient anti-thrombotic protection during HD procedure. Enoxaparin mean dose of 0.67 mg/kg, which is generally lower than manufacturer's instructions, can be recommended for over-dialytic regular use.