Switching from Lovenox to Angiomax in patients with acute coronary syndromes without ST elevation undergoing PCI - SWITCH


The goal of the trial was to evaluate the safety of treatment with bivalirudin among patients pre-treated for up to 12 hours with enoxaparin undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome without ST elevation.

Study Design

Study Design:

Patients Enrolled: 91
Mean Patient Age: Mean age 63 years
Female: 30

Patient Populations:

Age ≥18 years, acute coronary syndrome without ST elevation or marker elevation, scheduled for PCI, received enoxaparin 1 mg/kg subcutaneously within the last 12 hours.


ST elevation ≥1 mm in 2 contiguous leads, left branch bundle block, cardiogenic shock, active bleeding, platelet count <100,000 mm3, history of HIT, warfarin use

Primary Endpoints:

Major bleeding per REPLACE-2 definition

Secondary Endpoints:

Composite of death, MI, or unplanned revascularization for ischemia; minor bleeding; thrombocytopenia

Drug/Procedures Used:

All patients were treated with enoxaparin 1 mg/kg subcutaneous prior to PCI for various durations. Patients were randomized into those pre-treated for 0-4 hours pre-PCI (n=30), 4-8 hours (n=30) and 8-12 hours (n=31). During PCI, patients were treated with bivalirudin (0.75 mg/kg bolus and 1.75 mg/kg/hr intravenous infusion).

Concomitant Medications:

Aspirin and clopidogrel or ticlopidine

Principal Findings:

Baseline characteristics were well-balanced by treatment groups, with 301% diabetics, 39% having had a prior PCI, and 36% having had a prior MI. One-fourth of patients had been on treatment with clopidogrel prior to presentation. The average number of enoxaparin injections prior to PCI was 2.36 per patient. The glycoprotein IIb/IIIa inhibitor eptifibatide was used in 12% of patients, with an additional 3.3% receiving bailout eptifibatide.

Major bleeding did not differ by pre-treatment group (13% in the 0-4 hour group, 3% in the 4-8 hour group, and 7% in the 8-12 hour group, p=0.39). Likewise, there was no difference in minor bleeding (7%, 7%, and 0%, respectively, p=NS). There was also no difference in need for any transfusion (7%, 0%, and 7%, respectively, p=1.0) or ≥2 transfusions (3%, 3%, 7%, respectively, p=1.0). There were no ICHs and no cases of thrombocytopenia in the trial. There were no deaths or Q-wave MIs in the trial. Post-procedural non-Q-wave MI occurred in 13% in the 0-4 hour group, 7% in the 4-8 hour group, and 19% in the 8-12 hour group (p=NS).


Among patients with acute coronary syndrome without ST elevation undergoing PCI, varying duration of pre-treatment with enoxaparin followed by treatment with bivalirudin was not associated with differences in major bleeding. While the data suggested switching from enoxaparin to bivalirudin was not associated with increased bleeding or need for transfusion, the overall sample size was very small (n=91) and a much larger trial would be needed to fully evaluate safety. The bleeding rates in the present trial were slightly higher than those seen in the bivalirudin arm of the REPLACE-2 trial.


Waksman R, et al. Switching from Enoxaparin to Bivalirudin in Patients with Acute Coronary Syndromes without ST-segment Elevation who Undergo Percutaneous Coronary Intervention. Results from SWITCH--a multicenter clinical trial. J Invasive Cardiol. 2006 Aug;18(8):370-5.

Presented by Dr. Ron Waksman at the 2005 Cardiovascular Research Therapeutics Sessions, Washington, DC.

Clinical Topics: Acute Coronary Syndromes, Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention, Anticoagulation Management and ACS, Interventions and ACS

Keywords: Acute Coronary Syndrome, Enoxaparin, Peptide Fragments, Recombinant Proteins, Ticlopidine, Infusions, Intravenous, Hirudins, Thrombocytopenia, Diabetes Mellitus, Platelet Glycoprotein GPIIb-IIIa Complex, Percutaneous Coronary Intervention

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