Background: Neuregulin-1 (NRG-1) is a stress-mediated transmembrane growth factor. Reduced myocardial damage and higher NRG-1 levels upon treatment with remote ischemic conditioning (RIC) has been described in rats. However, the role of NRG-1 in patients with acute myocardial infarction (MI) is unknown. Thus, we conducted a post hoc analysis of a randomized controlled trial that tested RIC in patients with MI scheduled for primary percutaneous coronary intervention (PCI). Methods: Blood was drawn from 30 patients before RIC/PCI, within 1 hour, 4 days and 1 month later. Median left ventricular ejection fraction (LVEF) in the overall study population following MI was 48.5%. Results: NRG-1 plasma levels decreased significantly following PCI/RIC and remained decreased up to 1 month following MI (p 0.0001). We observed no association of NRG-1 with other variables, including total ischemic time, LVEF or RIC. Conclusions: Thus, we identified NRG-1 may be independently affected by MI. However, further large clinical trials are warranted to clarify this hypothesis.