Efficacy and tolerability of a very low molecular weight heparin compared with standard heparin in patients with unstable angina: a pilot study.

Background: Unstable angina is an active thrombotic process that involves thrombus formation and platelets. It requires a rapid and intensive treatment with anticoagulants and antiplatelets.

Hypothesis: The aim of the present study was to compare the efficacy of a very low molecular weight heparin, OP 2000, with standard heparin in the treatment of unstable angina. Tolerance and safety were also assessed.

Methods: The study population included 120 consecutive hospitalized patients with unstable angina randomized for treatment with very low molecular weight heparin or with standard heparin. The dosage of the study drug was 200 mg intramuscular (i.m.) the first day followed by 150 mg IM/day. The control drug was standard heparin starting at a dosage of 5,000 UI/ml intravenously (i.v.) and followed by continuous infusion at an activated partial thromboplastin time-adjusted dosage. The primary end points were death, acute myocardial infarction, urgent revascularization, and recurrence of angina. Tolerability was assessed using bleeding parameters, thrombocytopenia, and allergic reactions.

Results: Fourteen clinical events were reported in the study group compared with 25 events in the control group (p < 0.05). No adverse events were reported in either group.

Conclusion: During the acute phase of unstable angina, treatment with a very low molecular weight heparin plus aspirin was more effective than treatment with standard heparin plus aspirin.