Objectives: In this study, we tested whether iodide would reduce heart damage in rat and pig models of acute myocardial infarction as a risk analysis for a human trial.
Design: Prospective blinded and randomized laboratory animal investigation.
Setting: Animal research laboratories.
Subjects: Sexually mature rats and pigs.
Interventions: Acute myocardial infarction was induced by temporary ligation of the coronary artery followed by reperfusion. Iodide was administered orally in rats or IV in rats and pigs just prior to reperfusion.
Measurements and main results: Damage was assessed by blood cardiac troponin and infarct size; heart function was determined by echocardiography. Blood peroxide scavenging activity was measured enzymatically, and blood thyroid hormone was determined using radioimmune assay. Iodide administration preserved heart function and reduced blood cardiac troponin and infarct size by approximately 45% in pigs and approximately 60% in rats. Iodide administration also increased blood peroxide scavenging activity and maintained thyroid hormone levels.
Conclusions: Iodide administration improved the structure and function of the heart after acute myocardial infarction in rats and pigs.