Investigate the effect of selective intracoronary administration of adenosine on myocardial salvage and microvascular integrity in the setting of acute myocardial infarction.

Prospective, single center, randomized clinical study. Study design is random patient assignment to selective intracoronary administration of adenosine or control immediately before restoration of coronary artery patency in patients presenting with an acute ST segment-elevation myocardial infarction (STEMI). Randomisation will be stratified for the duration of symptoms (< 4 hours vs > 4 hours).

Inclusion Criteria:

• Myocardial infarction of less than 12 hours duration with symptoms lasting at least 20 minutes.
• ECG-criteria: ST-segment elevation of > 0.1 mV in 2 or more limb leads or > 0.2 mV in 2 or more contiguous precordial leads or presumed new left bundle branch block.
• Written informed consent prior to inclusion in the study. If this is not possible, verbal informed consent from the patient or written assent of a legally acceptable representative should be obtained, to be followed by written informed consent by the patient at the earliest subsequent opportunity.
• Adequate vascular access seems possible (femoral pulsation palpable).

Exclusion Criteria:

• Contra-indication to heparin, LMWH, clopidogrel.
• Anticipated difficulty with vascular access.
• Cardiogenic shock.
• Inability to give informed consent (or assent).
• High grade atrioventricular block; severe asthma; treatment with theophylline, glibenclamide (Diamicron) or dipyridamole.
• Prior CABG.
• Participation in an investigational drug or device study within the past 30 days.