Low molecular weight heparin versus unfractionated heparin in patients with acute non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention with drug-eluting stents

Background: Whether low molecular weight heparin (LMWH) enoxaparin is equivalent to unfractionated heparin (UFH) in patients with non-ST-segment elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) remains unclear.

Methods: A total of 2397 NSTEMI patients who underwent PCI with DES received either LMWH [n=1178, subcutaneous enoxaparin 1 mg/kg, b.i.d., initiated after the patient's arrival and continued until 3-5 days after PCI plus reduced dose of UFH (50-70 U/kg) during PCI] or UFH (n=1219, 24,000U/day infusion, initiated after the patient's arrival and continued until at least 48 h after PCI). The bleeding events and clinical outcomes during in-hospital and at 8 months were compared.

Results: Enoxaparin group had similar incidences of cardiac death, total death, and total major adverse cardiac events (MACE) at 8 months compared with UFH group. The incidences of major and minor bleeding events were also similar between the two groups. Multivariable Cox regression analysis showed that enoxaparin group had similar incidences of cardiac death [adjusted odds ratio (OR) 1.16, 95% confidence interval (CI) 0.64-2.10, p=0.620], total death (adjusted OR 1.08, 95% CI 0.66-1.76, p=0.760), and total MACE (adjusted OR 0.94, 95% CI 0.69-1.28, p=0.692) at 8 months as compared with UFH group.

Conclusions: Enoxaparin with reduced dose of UFH only during PCI as an adjunctive antithrombotic therapy in NSTEMI patients undergoing PCI with DES was safe and showed comparable 8-month clinical outcomes as compared with UFH alone.