Rapid Surface Cooling by ThermoSuit System Dramatically Reduces Scar Size,Prevents Post-Infarction Adverse Left Ventricular Remodeling,and Improves Cardiac Function in Rats

Background: the long-term effects of transient hypothermia by the non-invasive thermosuit apparatus on myocardial infarct (mi) scar size,left ventricular (lv) remodeling,and lv function were assessed in rat mi model.methods and results: rats were randomized to normothermic or hypothermic groups (n=14 in each group) and subjected to 30 minutes coronary artery occlusion and 6 weeks of reperfusion. for hypothermia therapy,rats were placed into the thermosuit apparatus at 2 minutes after the onset of coronary artery occlusion,were taken out of the apparatus when the core body temperature reached 32°c (in ≈8 minutes),and were then allowed to rewarm. after 6 weeks of recovery,rats treated with hypothermia demonstrated markedly reduced scar size (expressed as % of left ventricular area: hypothermia,6.5±1.1%; normothermia,19.4±1.7%; p=1.3×10(-6)); and thicker anterior lv wall (hypothermia,1.57±0.09 mm; normothermia,1.07±0.05 mm; p=3.4×10(-5)); decreased postmortem left ventricular volume (hypothermia,0.45±0.04 ml; normothermia,0.6±0.03 ml; p=0.028); and better lv fractional shortening by echocardiography (hypothermia,37.2±2.8%; normothermia,18.9±2.3%; p=0.0002) and lv ejection fraction by lv contrast ventriculography (hypothermia,66.8±2.3%; normothermia,56.0±2.0%; p=0.0014).conclusions: rapid,transient non-invasive surface cooling with the thermosuit apparatus in the acute phase of mi decreased scar size by 66.5%,attenuated adverse post-infarct left ventricular dilation and remodeling,and improved cardiac function in the chronic phase of experimental mi. © 2015 the authors. published on behalf of the american heart association,inc.,by wiley blackwell.