Following an acute myocardial infarction (AMI), early coronary artery reperfusion remains the most effective means of limiting
the eventual infarct size. The resultant left ventricular systolic function is a critical determinant of the patient’s clinical
outcome. Despite current myocardial reperfusion strategies and ancillary antithrombotic and antiplatelet therapies, the morbidity
and mortality of an AMI remain significant, with the number of patients developing cardiac failure increasing, necessitating
the development of novel strategies for cardioprotection which can be applied at the time of myocardial reperfusion to reduce
myocardial infarct size. In this regard, the Reperfusion Injury Salvage Kinase (RISK) Pathway, the term given to a group of
pro-survival protein kinases (including Akt and Erk1/2), which confer powerful cardioprotection, when activated specifically
at the time of myocardial reperfusion, provides an amenable pharmacological target for cardioprotection. Preclinical studies
have demonstrated that an increasing number of agents including insulin, erythropoietin, adipocytokines, adenosine, volatile
anesthetics natriuretic peptides and ‘statins’, when administered specifically at the time of myocardial reperfusion, reduce
myocardial infarct size through the activation of the RISK pathway. This recruits various survival pathways that include the
inhibition of mitochondrial permeability transition pore opening. Interestingly, the RISK pathway is also recruited by the
cardioprotective phenomena of ischemic preconditioning (IPC) and postconditioning (IPost), enabling the use of pharmacological
agents which target the RISK pathway, to be used at the time of myocardial reperfusion, as pharmacological mimetics of IPC
and IPost. This article reviews the origins and evolution of the RISK pathway, as part of a potential common cardioprotective
pathway, which can be activated by an ever-expanding list of agents administered at the time of myocardial reperfusion, as
well as by IPC and IPost. Preliminary clinical studies have demonstrated myocardial protection with several of these pharmacological
activators of the RISK pathway in AMI patients undergoing PCI. Through the use of appropriately designed clinical trials,
guided by the wealth of existing preclinical data, the administration of pharmacological agents which are known to activate
the RISK pathway, when applied as adjuvant therapy to current myocardial reperfusion strategies for patients presenting with
an AMI, should lead to improved clinical outcomes in this patient group.
Keywords Reperfusion injury - Protein kinases Akt - Erk1/2 - Myocardial infarction