[Use of unfractionated heparin and a low-molecular-weight heparin following thrombolytic therapy for acute ST-segment elevation myocardial infarction].

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.

CONCLUSIONS

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.