Myocardial infarct continues to be a major problem affecting a large number of adults. In a series of small animal experiments, it has been shown that application of hypothermia to the compromised heart is beneficial in reducing infarct size. If the heart is made hypothermic before reperfusion, hypothermia is capable of reducing infarct size by more than 50%. Unfortunately, when treatment of hypothermia was initially examined in human trials, results were not as positive. However, post-analysis of the clinical results showed that a subset of patients who were cooled prior to reperfusion demonstrated a reduction in infarct size;those cooled after reperfusion did not show such a benefit. Thus, approaches for faster, earlier cooling are of great interest in the setting of AMI treatment. During the past several years Life Recovery Systems HD, LLC, has been developing a device (the ThermoSuit. System) that can produce hypothermia much more rapidly than has been possible before with a noninvasive approach. It can potentially cool the entire body of an adult human at a rate of more than 8C0/hour. Because it is non-invasive it is also capable of being instituted rapidly in the Emergency Department, during the typical period of delay associated with preparations for PCI (Percutaneous Coronary Intervention). Furthermore it has the potential to be made into a portable system for even earlier application. In this application we propose to clinically evaluate the use of the ThermoSuit System to cool AMI patients prior to reperfusion. This 20-patient pilot clinical trial should demonstrate the speed and ease with which therapeutic hypothermia (32 to 340C) can be reached, whether this treatment delays door-to-balloon time, and how easily the target temperature is maintained after the patients are removed from the suit. The results will also enable a preliminary assessment of whether the ThermoSuit cooling treatment introduces any additional safety issues compared to historical treatment methods. This proposed study, in addition to a co-pending animal study of infarct size vs. reperfusion temperature, will support the approval of an FDA sanctioned pivotal trial in humans for the condition of myocardial infarct.
The use of mild hypothermia to reduce the infarct size in animals subsequent to injury has been examined by a number of recent investigations. However, despite success in small animals, the clinical results have not been positive. It is hypothesized that the timing and speed with which temperature can be lowered is a key factor. The present proposal will apply a device which can drop the temperature in a rapid but controlled fashion. This will be examined in a clinical population of 20 patients. This should provide initial data proving safety and will pave the way for a pivotal trial required by the FDA for this device.
| Howes, Daniel; Ohley, William; Dorian, Paul et al. (2010) Rapid induction of therapeutic hypothermia using convective-immersion surface cooling: safety, efficacy and outcomes. Resuscitation 81:388-92 |
| Janata, Andreas; Weihs, Wolfgang; Bayegan, Keywan et al. (2008) Therapeutic hypothermia with a novel surface cooling device improves neurologic outcome after prolonged cardiac arrest in swine. Crit Care Med 36:895-902 |
