Primary objective: to evaluate the procoagulant effect of TNK-tPA compared to rt-PA and streptokinase, administered to patients with AMI, by measuring the concentration of TAT at 2 hours after the start of treatment versus baseline values.

Secondary objective: change from baseline in concentration of TAT at 6 and 24 hours; change from baseline in concentration of D-dimers, F1+2, PAI-1, PAP at 2, 6 and 24 hours. Incidence of adverse events (AE's), in -hospital complications, major or minor bleedings and serious adverse events.

Inclusion Criteria:

• Onset of symptoms of AMI within 6 hours from randomisation
• A twelve-lead electrocardiogram (ECG) showing ST-segment elevation ≥ 0.1 millivolt (mV) in two or more limb leads, or ≥ 0.2 mV in two or more contiguous precordial leads indicative of AMI, or new left bundle-branch block
• Age ≥ 18

Exclusion Criteria:

• Hypertension defined as blood pressure > 180/110 mmHg (systolic BP > 180 mmHg and/or diastolic BP > 110 mmHg) on repeated measurements during current admission prior to randomisation
• Use of abciximab (ReoPro®) within the preceding 7 days or eptifibatide (Integrilin®) or tirofiban (aggrastat®) within the past 48 hours
• Use of heparin within the preceding 12 hours
• Current therapeutic oral anticoagulation
• Major surgery, biopsy of a parenchymal organ, or significant trauma within 2 months
• Any minor head trauma and any other trauma occurring after the onset of the current myocardial infarction
• Any known history of stroke or transient ischemic attack or dementia
• Any known structural damage of the central nervous system
• Ruptured aortic aneurism
• Active bleeding
• Prolonged cardiopulmonary resuscitation (> 10 minutes) in the previous two weeks
• Pregnancy or lactation, parturition within the previous 30 days. Women of childbearing potential must have a negative pregnancy test
• Any known active participation in another investigative drug study or device protocol in the past 30 days
• Previous enrolment in this study
• Any other condition that the investigator feels would place the patient at increased risk if the investigational therapy were initiated
• Inability to follow the protocol and comply with follow-up requirements