• MTH improved survival and neurological outcomes in adult rats after CA. • Aged rats showed no benefit from MTH in survival, function, or inflammation. • IL-6 and IL-17 levels were reduced by MTH only in adult, not aged, rats. • Hippocampal neuronal apoptosis was mitigated by MTH in adults only. • Age alters neuroprotective and anti-inflammatory effects of MTH after CA. To investigate age-related differences in the neuroprotective effects and mechanisms of mild therapeutic hypothermia (MTH) after cardiac arrest (CA) to inform age-specific therapeutic strategies. Overall, 660 patients after CA were selected from the clinical databases for further validation analysis using a random forest model. 183 male rats underwent 6-min asphyxia CA and were randomized into adult (12-16 weeks) or aged (76-84 weeks) groups: sham (without CA, 37°C), sham + MTH (without CA, 33°C for 2h), control (induced CA, 37°C), and MTH (induced CA, 33°C for 2h). Over a 5-day post-return of spontaneous circulation (ROSC) period, survival, neurological function (deficit scores and locomotor activity), interleukin (IL)-17/IL-6 levels (serum and hippocampus), and CA1 neuronal apoptosis were evaluated. Clinical data analysis identified a significant interaction between age and MTH in predicting survival probability (β=-0.15, P 0.05). Aged rats showed no benefit from MTH in survival, function, or inflammation compared to adult rats. Age alters the neuroprotective and anti-inflammatory effects of MTH after CA.
Zhai et al. (Fri,) studied this question.