Aims: To determine the impact of a strategy using enoxaparin for up to 8 days compared with unfractionated heparin (UFH) for 48 h as an adjunct to fibrinolysis for ST-segment elevation myocardial infarction (STEMI) on 1-year clinical outcomes.
Methods and results: Follow-up at 1 year (n = 20 275) was conducted by telephone in the ExTRACT-TIMI 25 trial to ascertain the endpoints of death, MI, and disabling stroke. The primary endpoint of death or non-fatal MI occurred in 1614 (15.8%) and 1732 (17.0%) of patients allocated to enoxaparin and UFH, respectively [hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.86-0.98, P = 0.01]. The enoxaparin strategy significantly reduced non-fatal MI at 1 year (5.7 vs. 6.8%, HR 0.82, 95% CI 0.73-0.92, P < 0.001). The risks of death (10.5 vs. 10.6%, HR 0.98, 95% CI 0.91-1.07) and disabling stroke (1.1 vs. 1.2%, HR 0.97, 95% CI 0.75-1.26) were not reduced. The composite of death, MI, or disabling stroke favoured enoxaparin (HR 0.91, 95% CI 0.85-0.98, P = 0.007).
Conclusion: Compared with UFH for 48 h, a strategy using enoxaparin as an adjunct to fibrinolysis resulted in a sustained reduction in death or MI at 1 year with no additional benefit after 30 days. Mortality was not reduced at 1 year with the enoxaparin strategy. The study was registered at ClinicalTrials.gov, NCT00077792.