Intravenous Interferon-β1a for the Treatment of Ischemia-Reperfusion Injury in Acute Myocardial Infarct in Pigs

BACKGROUND: To investigate the potential of intravenously administered porcine recombinant interferon-β1a (IFN-β1a) for myocardial protection during acute ischemia-reperfusion (IR) injury in an experimental animal model. METHODS: Twenty-two piglets (mean ± standard deviation, 26.7 ± 1.65 kg) were assigned to either the IFN group (n = 12) or the control group (n = 10). IR injury was induced by occluding the distal left descending coronary artery for 30 minutes, with a reperfusion period of 6 h. In the IFN group, the animals received 12.5 µg IFN-β1a intravenously repeatedly; the control group received saline solution. The levels of interleukin-6 (IL-6) and cardiac troponin I (TnI) were measured, and the amount of myocardial damage was quantified by analyzing myocardial apoptosis and the mean fluorescence intensity (MFI) of methylene blue-stained cardiac tissue. RESULTS: In the IFN group, significantly more premature deaths occurred compared with the control group (25% versus 17%, P = .013). Between the groups, the mean heart rate was higher in the IFN group (102 ± 22 versus 80 ± 20 beats per minute, P = .02). IL-6 and TnI levels were comparable between the groups, with no significant difference, and there was no difference between the study groups in myocardial apoptosis in the infarcted myocardium. The percentage of MFI differed significantly between the IFN and control groups (90.75% ± 4.90% versus 96.02% ± 2.73%, P = .01). CONCLUSION: In this acute IR injury animal model, IFN-β1a did not protect the myocardium from IR injury, but rather increased some of the unfavorable outcomes studied.