Intravenous enoxaparin or unfractionated heparin in primary percutaneous coronary intervention for ST-elevation myocardial infarction: the international randomised open-label ATOLL trial
Topic: Anticoagulation in acute coronary syndrome (unfractionated heparin and low molecular weight heparin)
Aim:
- IV enoxaparin is superior to IV unfractionated heparin in acute MI
Design:
- Multi-centered, open labeled, randomized clinical trial
Treatment:
- IV enoxaparin (0.5 mg/kg)
Control:
- IV unfractionated heparin (70-100 IU/kg; 50-70 IU/kg if receiving concomitant glycoprotein 2b/3a inhibitor)
Cohort:
- 910 participants
Inclusion criteria:
- Patients presenting with STEMI
Exclusion criteria:
- Patients received any anticoagulant before randomization
- Patients requiring crossover from enoxaparin to unfractionated heparin during or after the procedure
Follow up:
- 30 days
Primary endpoint:
- 30-day incidence of death, complication of myocardial infarction, procedure failure, or major bleeding
Secondary endpoint:
- Composite of death, recurrent acute coronary syndrome, or urgent revascularization
Main results:
- Primary endpoint occurred in 126 (28%) patients after anticoagulation with enoxaparin versus 155 (34%) patients on unfractionated heparin (RR 0.83, 95% CI 0.68-1.01; p = 0.06)
- Enoxaparin group had significantly reduced rate of main secondary endpoints evaluating ischemic outcomes (death, recurrent MI or ACS, or urgent revascularization): 30 (7%) vs 52 (11%) (RR 0.59, 95% CI 0.38-0.91; p = 0.015)
- Net clinical benefit defined as death, complication of MI, or major bleeding was significantly reduced with enoxaparin; 46 (10%) vs 69 (15%) (RR 0.68, 95% CI 0.48-0.97, p = 0.03)
- Stacking or switching of drugs (although prohibited in study, did occur in a few patients, number not reported) was associated with worsened clinical outcomes
TAKE AWAY: IV enoxaparin reduced secondary, but not primary, endpoints of adverse ischemic events without a significant difference in bleeding.
