The proposed anticoagulant intervention is a parenteral (intra-arterial or intravenous; IA/IV) bolus dose of enoxaparin (0.5 mg/kg) at the time of PPCI followed by an infusion of 0.5 mg/kg over a 6-hour period. In patients with impaired kidney function (eGFR < 30 ml/min), the infusion will be stopped at 3 hours (cumulative dose of 0.75 mg/kg).