Effect of Low-dose Intracoronary Reteplase on Myocardial Infarct Size During Primary Percutaneous Coronary Intervention

OBJECTIVE: To determine whether a therapeutic strategy involving low-dose intracoronary fibrinolytic therapy with reteplase infused after coronary reperfusion will reduce the myocardial infarction size. DESIGN, SETTING, AND PARTICIPANTS: 306 patients presenting at 15 hospitals in China within 12 hours of acute ST-segment elevation myocardial infarction (STEMI) due to a proximal-mid-vessel occlusion of left anterior descending (LAD) coronary artery occlusion will be randomized in a 1:1:1 dose-ranging trial design. Patients will be followed up to 1 month. INTERVENTIONS: Participants will be randomly assigned to treatment with placebo (n = 102), reteplase 9mg (n = 102), or reteplase 18mg (n = 102) by manual infusion over 2 minutes after reperfusion of the infarct-related coronary artery and before stent implant. MAIN OUTCOMES AND MEASURES The primary outcomewas the myocardial infarct size (% left ventricular mass) demonstrated by contrast-enhanced cardiac magnetic resonance imaging (MRI) conducted from days 2 through 7 after enrollment.