Background: Animal studies have shown that the superoxide dismutase mimetic mangafodipir (manganese dipyridoxyl diphosphate) with an active metabolite (manganese dipyridoxyl ethyldiamine) reduces reperfusion injuries and thereby infarct size in acute myocardial infarction (MI). In this small pilot trial we attempted to assess the feasibility of applying mangafodipir as a cardioprotective adjunct to Percutaneus Coronary Intervention (PCI).
Methods: 20 patients with their first acute ST-elevation MI (STEMI) were assigned into two groups receiving an intravenous bolus dose of mangafodipir, 2 μmol per kilogram of body weight, or saline (control group) immediately before performing PCI. Infarct size was assessed by ST-segment changes, release of plasma biomarkers and cardiac magnetic resonance imaging (MRI) at routine follow up.
Results: On cardiac MRI, the mangafodipir group revealed a smaller mean infarct size (26.2% scar vs 32.5%) and a higher mean ejection fraction (47.7 % vs 41.8 %), despite a significant prolonged ischemia time (205 min vs 144 min). ST-segment elevation also regressed more rapidly in the mangafodipir group, whereas there were no apparent differences in biomarker release.
Conclusions: In this small local feasibility study with a skewed distribution of patients the administration of mangafodipir at the time of reperfusion was associated with a non-significant smaller scar tissue and better ejection fraction compared with placebo. The results give the impression that mangafodipir may reduce infarct size in STEMI patients, however this require confirmation in a larger clinical trial. No adverse effects of mangafodipir administration were detected.