Aims: At least one quarter of ST-segment elevation myocardial infarction (STEMI) patients do not receive reperfusion therapy, and these patients are at high risk for new ischaemic events. We evaluated fondaparinux treatment vs. usual care, i.e. placebo or unfractionated (UF) heparin, in a pre-specified subgroup of 2867 (out of 12 092) patients not receiving reperfusion treatment in the OASIS-6 trial.
Methods: In all, 1458 patients were randomized to fondaparinux 2.5 mg once daily subcutaneously up to 8 days and 1409 patients to usual care (control). Randomization was stratified by indication for UF heparin (stratum II, n = 1226) or not (stratum I, n = 1641) based on the investigator's judgment.
Results: The proportion of patients who suffered death or myocardial re-infarction at 30 days (primary outcome) was 12.2% in the fondaparinux vs. 15.1% in the control group, hazard ratio (HR) 0.80; 95% confidence interval (CI) 0.65-0.98. There was no increase in severe bleedings, HR 0.82; CI 0.44-1.55, or strokes, HR 0.62; CI 0.29-1.33. Consequently, the composite of death, myocardial re-infarction, or severe bleeding were significantly reduced at 30 days, HR 0.81; CI 0.67-0.99. Reductions in death or myocardial re-infarction at 30 days were consistent in stratum I with fondaparinux vs. placebo, HR 0.88; 95% CI 0.65-1.19, and in stratum II with fondaparinux vs. UF heparin infusion for 24-48 h (n = 806), HR 0.74; CI 95% 0.57-0.97, P = 0.41 for heterogeneity.
Conclusion: In STEMI patients not receiving reperfusion treatment, fondaparinux reduces the composite of death or myocardial re-infarction without an increase in severe bleedings or strokes as compared to placebo or UF heparin.