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

Effect of Low-dose Intracoronary Reteplase During Primary Percutaneous Coronary Intervention on Myocardial Infarct Size in Patients With Acute Myocardial Infarction

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.

Inclusion Criteria:

1. Acute STEMI with persistent ST-segment elevation or recent left bundle-branch block with a symptom onset to reperfusion time of 12 hours or less.
2. Angiographic criteria included a proximal-mid coronary artery occlusion (TIMI coronary flow grade 0 or 1) or, impaired coronary flow (TIMI flow grade 2, slow but complete filling) in the presence of definite angiographic evidence of large thrombus (TIMI grade ≥2) in left anterior descending (LAD) coronary artery.

Exclusion Criteria:

1. Rescue PCI after thrombolytic therapy.
2. Need for emergency coronary artery bypass grafting.
3. Presence of cardiogenic shock.
4. Life expectancy of < 6 months.
5. Inability to provide informed consent.
6. Contraindications for the use of thrombolysis, including active internal bleeding, history of intracranial haemorrhage or ischaemic stroke within 6 months, recent major surgery or trauma, severe uncontrolled hypertension, thrombocytopenia and severe liver or kidney failure.