Cardioprotection by very mild hypothermia in mice

Target temperature management is recommended in post-resuscitation care. Additionally, hypothermia is a promising option in adjunctive therapy of acute myocardial infarction (MI). However, first in men data are contradicting. There are still many open questions to identify the optimal regimen and target temperature. In this study, we aimed to investigate the effect of very mild hypothermia on infarct size (IS) in mice. Mice underwent cardiac ischemia by temporary occlusion of the left anterior descending (LAD) artery under conditions of very mild hypothermia (34-36 degrees C). Hypothermia was reached within the first 5 minutes of ischemia (temperature: 34.6 +/- 0.5 vs. 36.8 +/- 1.1., P=0.035). Very mild hypothermia reduced IS in mice undergoing 30 minutes ischemia [IS/area at risk (AAR): 45 +/- 12% vs. 22 +/- 4%, P=0.018] as well as mice undergoing 60 minutes ischemia [IS/AAR: 67 +/- 7% vs. 28 +/- 2%, P=0.0003]. Very mild hypothermia reduces IS. This new approach in adjunctive therapy of patients with acute MI should be investigated in clinical trials.