Hypothermia for Cardioprotection in Patients with St-Elevation Myocardial Infarction: Do Not Give It the Cold Shoulder Yet!

Abstract

The timely revascularization of an occluded coronary artery is the cornerstone of treatment in patients with ST-elevation myocardial infarction (STEMI). As essential as this treatment is, it can also cause additional damage to cardiomyocytes that were still viable before reperfusion, increasing infarct size. This has been termed “myocardial reperfusion injury”. To date, there is still no effective treatment for myocardial reperfusion injury in patients with STEMI. While numerous attempts have been made to overcome this hurdle with various experimental therapies, the common denominator of these therapies is that, although they often work in the preclinical setting, they fail to demonstrate the same results in human trials. Hypothermia is an example of such a therapy. Although promising results were derived from experimental studies, multiple randomized controlled trials failed to do the same. This review includes a discussion of hypothermia as a potential treatment for myocardial reperfusion injury, including lessons learned from previous (negative) trials, advanced techniques and materials in current hypothermic treatment, and the possible future of hypothermia for cardioprotection in patients with STEMI.

Intracoronary Application of Super-Saturated Oxygen to Reduce Infarct Size Following Myocardial Infarction

“…Respective clinical trials are either on their way or in the stage of planning. Theoretically, it is appealing to think about combining these strategies, for example, by infusing SSO 2 through cooled blood providing additive intracoronary hypothermia [ 20 ] or applying it while the LV is unloaded by a microaxilar flow-pump that reduces microvascular resistance and might thereby improve plasma flow and oxygen diffusion [ 50 ].…”

“…As the diffusion through plasma appears to be a central issue for successful prevention of myocardial injury, it also provides a pathophysiological rational why SSO 2 in contrast to LV unloading or hypothermia either requires or benefits from revascularisation prior to application. On the other hand, this provides the clinical advantage of not delaying primary PCI compared to the other methods [ 20 , 22 ].…”

“…Hypothermia of 32 °C body temperature requiring 18 min delay for primary PCI has also been investigated and provided differing results [ 18 , 19 ]. As the topic of hypothermia is well validated to reduce cerebral reperfusion injury presumably by reducing mitochondria-related oxygen radical formation, it is discussed in more detail in a separate review in this edition [ 20 ]. Another approach to target mitochondrial radical formation is left-ventricular unloading using an Impella microaxial pump [ 21 ].…”

Hypothermia: what are the trends in recent studies? – a bibliometric analysis with global productivity

“…(26,27). For this reason, millions of people lose their lives every year (28). This situation continues to be a global health problem despite all the precautions and developments in treatment strategies.…”

Interventional Cardiology: Current Challenges in Acute Myocardial Infarction

“…While a pilot trial rapidly applying systemic hypothermia to reduce infarct size did not provide positive conclusive results [ 25 ], selective intracoronary cooling seems to be a safe and promising approach [ 26 ]. In this issue, El Farissi et al discuss the role of intraprocedural hypothermia during reperfusion [ 27 ]. The other technique aiming to mitigate reperfusion injury is intracoronary application of super-saturated oxygen, which allows for diffusion of dissolved oxygen into the periphery of the ischaemic area and reduces microvascular obstruction by preventing endothelial cell edema [ 28 ].…”