The present feasibility study is designed to find out whether pre-treatment with the compound mangafodipir (PP-099) provides an additional reduction in myocardial infarct size in patients treated with primary percutaneous coronary intervention (PCI) during acute myocardial infarction (AMI).

Mangafodipir, manganese (Mn) dipyridoxyl diphosphate (MnDPDP) and its lipophile metabolite Mn dipyridoxyl diethylene diamide (MnPLED), are catalytic antioxidants and iron chelators. In preclinical studies these agents reduce oxidative stress induced injuries related to chemotherapy of cancer and to reperfusion/reoxygenation of ischemic/hypoxic myocardium. Accordingly, in an in vivo pig model of AMI metabolite MnPLED applied at end of ischemia and during reperfusion reduced myocardial infarct size by 55 %. Mangafodipir most likely activates salvage pathways and prevents lethal reperfusion injuries.

Other advantages are that mangafodipir is already approved as a contrast agent for MRI of liver, and that the experience for more than a decade reveals a high safety with minor and tolerable side-effects.

The present study will include 20 patients treated for their first documented AMI. They will after admission to hospital undergo primary PCI. Reopening of an occluded coronary artery will be preceded by iv. infusion of mangafodipir or placebo in two groups , each consisting of 10 patients. The primary endpoint will be release to plasma of commonly accepted biomarkers of myocardial injury (Troponin T and CK-MB) measured at admission and 6 hours after PCI. The secondary endpoints include the accumulated release of plasma biomarkers over 48 hours and direct measurement of the final myocardial infarct size at 6-10 weeks after PCI.

Inclusion Criteria:

1. Males 40-80 and females 50-80 years with first severe coronary attack
2. Chest pain up to 6 hours.
3. T segment elevation (≥ 0.2 mV in two neighbouring anterior and inferior wall leads.
4. Decided for treatment by primary PCI.
5. TIMI grade 0 flow in the occluded LAD or RCA artery
6. Written informed consent.

Exclusion Criteria:

1. Previous coronary artery bypass operation.
2. Previous AMI.
3. Chest pain more than 6 hours.
4. Angina within 48 hours before admission.
5. Cardiac arrest and cardiogenic shock.
6. Occlusion of the left main stem, circumflex and right coronary arteries at angiography.
7. Known hypersensitivity to mangafodipir (as contrast agent for MRI).
8. Received mangafodipir ≤ 5 weeks before admission
9. History of prior serious allergic or pseudo-allergic reaction
10. Severely reduced liver or renal function
11. Any other serious illness or medical condition
12. Fertile females
13. Phaeochromocytoma