Janssens SP, et al. - Considering the preclinical studies suggesting cardioprotection conferred by inhalation of nitric oxide (iNO) during myocardial ischaemia and after reperfusion via enhanced cyclic guanosine monophosphate (cGMP) signalling, researchers investigated if iNO reduces reperfusion injury in patients with ST-elevation myocardial infarction. In a double-blind, placebo-controlled study, 250 ST-elevation myocardial infarction (STEMI) patients were randomized to inhale oxygen with (iNO) or without (CON) 80 parts-per-million NO for 4 h following percutaneous revascularization. Outcomes suggested that inhalation of NO at 80 ppm for 4 h in STEMI was safe, however, it did not reduce infarct size relative to absolute LVmass at 48–72h.