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.