Comparison of Fondaparinux and Enoxaparin in Non-ST Elevation Acute Coronary Syndrome.

BACKGROUND : The OASIS-5 trial demonstrated that fondaparinux was noninferior to enoxaparin while reducing the risk of bleeding by 50%. The objective of our study was to assess the effects of fondaparinux in patients with unstable angina or NSTEMI compared to historical controls treated with enoxaparin. This study is designed to assess the utility of fondaparinux in our current clinical practice. METHODS : We prospectively included 40 patients with unstable angina or NSTEMI to receive fondaparinux (2.5 mg daily) for a mean duration of 5 days and evaluated the composite of death, myocardial infarction, or refractory ischemia at 30 days as the primary efficacy outcome and major bleeding or stroke at 1 month as the primary safety outcome. Historical controls included 44 patients treated with enoxaparin 1mg/kg twice daily. RESULTS : The effect of fondaparinux versus enoxaparin on the primary composite outcome of death, myocardial infarction, and refractory ischemia at 30 days was similar (27.5% versus 34% p=0.51). The differences in rates of death or refractory ischemia at 30 days between the 2 groups were also not statistically significant (5% versus 6.8%, p=0.72 and 22.5% versus 27.2%, p=0.61). There was no documented myocardial infarction, major or minor bleeding or stroke during the study period. There was a non-significant trend toward a lower 1 week mortality in the fondaparinux group (0% vs. 6.8%, P=0.09). The rate of revascularization procedures at 1 month was similar between the 2 groups. When compared to OASIS 5 trial, patients in our study had more frequent hospitalizations for refractory ischemia but less revascularization procedures. CONCLUSION : In this study fondaparinux was found not superior to enoxaparin in the treatment of unstable angina/NSTEMI when primary composite outcome measures are compared at 1 month. Expected reduction in major/minor bleeding and stroke with fondaparinux was not found in this trial. This is likely to be due to small number of patients and low rates of revascularization procedures