Moderate therapeutic hypothermia with mechanical left ventricular unloading on non-infarct area in an acute...

Patients with cardiogenic shock due to acute myocardial infarction (AMI) treated with ECPELLA support have a poor prognosis. Impaired left ventricular (LV) wall motion is observed in both infarcted and non-infarcted areas. Therapeutic hypothermia and mechanical LV unloading have different myocardial protective effects. This study aimed to evaluate myocardial protective effects of moderate therapeutic hypothermia combined with mechanical LV unloading in non-infarcted areas using a porcine AMI model. The coronary artery was ligated, and an extracorporeal ventricular assist device was driven under mean left atrial pressure of 5 mmHg. Cooling was initiated via the thermostatic bath of ECMO 30 min after LAD ligation. Moderate therapeutic hypothermia (30-31 °C) was maintained for 2 h. The final evaluation was performed 30 min after rewarming. In the control group, LV fractional shortening (FS) and LV posterior wall motion score (WMS) were declined. In the hypothermia group, LVFS and LV posterior WMS were preserved. In the posterior wall of hypothermia group, mitochondria structure was maintained, reactive oxygen species production was reduced, and sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase expression was maintained more than in the control group. Moderate therapeutic hypothermia combined with mechanical LV unloading might provide more myocardial protection in non-infarcted areas compared to mechanical LV unloading alone in a porcine AMI model.