Percutaneous coronary intervention in patients receiving enoxaparin or unfractionated heparin after fibrinolytic therapy for ST-segment elevation myocardial infarction in the ExTRACT-TIMI 25 trial

Abstract

Objectives: We sought to evaluate whether enoxaparin (ENOX) is superior to unfractionated heparin (UFH) as adjunctive therapy for patients with ST-segment elevation myocardial infarction (STEMI) who receive fibrinolytic therapy and subsequently undergo percutaneous coronary intervention (PCI) by analyzing data from the ExTRACT-TIMI 25 (Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction 25) trial.

Background: Limited data are available on the use of ENOX compared with UFH as adjunctive therapy in STEMI patients treated with fibrinolytic therapy and subsequent PCI.

Methods: A total of 20,479 STEMI patients who received fibrinolytic therapy were randomized to a strategy of ENOX throughout index hospitalization or UFH for at least 48 h, with blinded study drug to continue if PCI was performed. The primary end point of death or recurrent MI through 30 days was compared for ENOX versus UFH among the patients who underwent subsequent PCI (n = 4,676).

Results: After initial fibrinolysis, fewer patients underwent PCI through 30 days in the ENOX versus the UFH group (22.8% vs. 24.2%; p = 0.027). Among patients who underwent PCI by 30 days, the primary end point occurred in 10.7% of ENOX and 13.8% of UFH patients (0.77 relative risk; p < 0.001). There were no differences in major bleeding for ENOX versus UFH (1.4% vs. 1.6%; p = NS). Results were similar when PCI was carried out in patients receiving blinded study drug during PCI (n = 2,178).

Conclusion: Among patients treated with fibrinolytic therapy for STEMI who underwent subsequent PCI, ENOX administration was associated with a reduced risk of death or recurrent MI without difference in the risk of major bleeding. The strategy of ENOX support for fibrinolytic therapy followed by PCI is superior to UFH and provides a seamless transition from the medical management to the interventional management phase of STEMI without the need for introducing a second anticoagulant in the cardiac catheterization laboratory.