Head-to-Head Comparison of Two Different Low-Molecular-Weight Heparins in Acute Coronary Syndrome

Low-molecular-weight heparins (LMWH) of different types have yielded different results when used in the setting of unstable angina (UA) or non Q-wave myocardial in-farction (NQMI). We compared the safety and therapeutic efficacy of two different LMWHs, namely dalteparin (Dalt.) and enoxaparin (Enox.), in the acute phase (first 5 days) of UA or NQMI. One hundred and forty-two patients with UA/NQMI were randomly assigned to treatment with either Dalt. [120 IU/kg twice daily by subcutaneous (SC) injection] or Enox. [1 mg/kg twice daily by SC injection]. The occurrence of any one of death, myocardial infarction, or angina recurrence within 5 days of the first LMWH injection was the endpoint of the study. There were 69 patients in the Enox. group (53 males, 16 females, mean age : 60.3±11.9) and 73 patients in the Dalt. group (54 males, 19 females, mean age : 59.6 ±10.3). The baseline characteristics of the patients in the two groups were similar. There were no deaths in either group. Myocardial infarction occurred in two patients in the Dalt. group (4%). Angina recurrence was seen in 11 patients in the Enox. group (16%) and in 11 patients in the Dalt. group (15%). Overall, any of the events that made up the endpoint occurred in 11 (16%) and 14 (19%) patients in the Enox. and Dalt. groups, respectively (P>0.05). The time to occurrence of the first event, however, was significantly longer in the Enox. group (82.3±33.2 versus 37.6±23.4 hours, P=0.007). Thrombocytopenia and allergic reactions were not detected in any patient. Major bleeding was seen in 1 patient in the Enox. group. Minor bleeding occurred in 17 (25%) and 21 (29%) patients in the Enox. and Dalt. groups, respectively (P>0.05). Enoxaparin and dalteparin were found to be equally safe and effective for the early management of UA/NQMI, but enoxaparin appeared to delay the occurrence of MI or angina recurrence as compared to dalteparin in this setting.