Wang YS, et al. - Researchers evaluated how selective intracoronary hypothermia could modify outcomes in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). A total of 60 STEMI patients with thrombolysis in myocardial infarction (TIMI) flow grade 0/1 were selected to perform coronary artery angiography, after which the patients were randomized. Thirty patients received intracoronary hypothermia induced by selective trans-coronary infusion of saline at 4°C to the endangered myocardium. A predominant attenuation in mean infarct size (IS)/myocardium at risk (MaR) was seen in the hypothermia group, this was specifically seen in the anterior STEMI subgroup, and this finding is important. In addition, with regard to clinical events, no statistical difference was noted between the two groups at the 30-day follow-up. As adjunctive to PPCI, intracoronary hypothermia resulted in statistical difference in IS/MaR.