Objective: To compare the efficacy and safety of unfractionated heparin with a low-molecular-weight heparin (parnaparin) in the management of anticoagulation following thrombolytic therapy for acute ST-segment elevation myocardial infarction.
Methods: One hundred and eighty-six patients with acute ST-segment elevation myocardial infarction undergoing thrombolytic therapy were randomly assigned to receive either unfractionated heparin (100 U/kg x b.w. intravenous bolus, 1,000 U/h continuous infusion for 3 days just 12 h after thrombolysis to maintain the activated partial thromboplastin time at 1.5 to 2.0 times as normal, then subcutaneous 7500 U every 12 h for 4 days, n=90) or parnaparin (0.4 ml subcutaneously every 12 h for 7 days 12 h after thrombolysis, n=96) in conjunction with routine therapy. The patients enrolled stayed in hospital for at least 14 days and were followed for 45 days after admission into the hospital.
Results: The composite triple end-point (death, recurrent myocardial infarction, emergency revascularization assessed at 2, 7, 14, 45 days) was significantly reduced in patients receiving parnaparin 42.22% vs 37.08%, P=0.03 . Compared with unfractionated heparin group, the incidences of hemorrhage 10.00% vs 3.13%, P=0.06 and heparin-induced thrombocytopenia (3.33% vs 0, P=0.07) were also lower in parnaparin group.
Conclusion: Parnaprin is more effective in reducing composite cardiac events, hemorrhage and heparin-induced thrombocytopenia at least in 45 days as compared with unfractionated heparin during anticoagulation following thrombolytic therapy for acute ST-segment elevation myocardial infarction.