Cardiac function is crucial for cardiac surgery. Unfortunately, mortality remains very
high in patients with poor preoperative cardiac function, long surgical times, complicated
or difficult surgical procedures, or incomplete correction of the malformation. It is
therefore necessary to find novel approaches to improve cardiac function for cardiac
surgery patients in order to simultaneously increase success rates and decrease
complications and mortality.1 When the coronary circulation is interrupted, the size of the
resulting infarct is proportional to the duration of ischemia.2 Paradoxically, even early
revascularization leads to tissue damage, a phenomenon known as ischemia reperfusion
injury,3 which is estimated to be responsible for up to 30% of infarct size.4 This has
prompted a search for cytoprotective mechanisms that make the myocardium less
vulnerable to such damage, not only in acute settings (as in revascularization in the
context of acute coronary syndrome [ACS]) but also following surgical procedures that
entail temporary interruption of the coronary circulation, particularly cardiac surgery with
aortic clamping and heart transplantation.5 Inducing non-lethal and brief ischemia before
the period of prolonged ischemia has been considered as a tool for increasing the heart’s
resistance to ischemia-reperfusion (I/R) injury.6,7 Subsequently, preconditioning the heart
with ischemia was shown to maintain its cardioprotective abilities even if the non-lethal
ischemic stimulus was applied not directly to the targeted tissue, but to any distant site of
the organism – hence the idea of remote ischemic preconditioning (RIPC).8 In cardiac
surgery, where the timing of global ischemia and reperfusion periods is predictable, the
application of RIPC seemed a perfect solution.9 This technique was used in patients for
the first time in children undergoing corrective surgery for congenital heart disease, in
whom it was shown to reduce troponin release 24 h postoperatively.10The aim of this
study was to determine if RIPC could induce myocardial protection in single valve
replacement patients. We conducted a randomised controlled clinical trial in which RIPC
was induced by upper limb brief ischemia and reperfusion using blood pressure cuff
inflation. Myocardial injury was evaluated by postoperative serum troponin levels and
compared between the RIPC and control groups. |
