Anti-Xa activity of enoxaparin and nadroparin in patients with acute coronary syndrome

Background: Clinical studies have clearly revealed that low-molecular-weight heparins (LMWHs) are an effective alternative to unfractionated heparin in the therapy of acute coronary syndrome (ACS); however, data on the comparison of different LMWHs are sparse.

Aim: To compare the inhibition of coagulation factor Xa by enoxaparin and nadroparin in the therapy of ACS.

Methods: Thirty-eight consecutive patients with ACS were randomly assigned to enoxaparin (group E, n=18) or nadroparin (group N, n=20) in the recommended dose. Anti-Xa activity was measured 3 h after administering the first dose of LMWH.

Results: Baseline demographics (age, sex) and clinical (type of ACS, pain-to-door time, elevation of troponin, percutaneous coronary intervention performed, smoking status, and history of diabetes, hypertension and hyperlipoproteinemia) characteristics were similar in both groups. Anti-Xa activity was significantly higher in group E than in group N (0.65+/-0.05 U/mL versus 0.30+/-0.03 U/mL; P<0.001). Moreover, the therapeutic target (0.5 U/mL to 0.8 U/mL) was achieved in 66.7% of patients in group E; on the other hand, effective therapy was observed in 10.0% of patients in group N (P<0.001).

Conclusions: The results of the present study demonstrate a highly significant difference in anti-Xa activity of enoxaparin and nadroparin in their recommended dosing regimens, in the therapy of ACS 3 h after subcutaneous administration; the anticoagulant effect of enoxaparin was markedly stronger than that of nadroparin.