Spotlight on cardioprotection against ischemia-reperfusion injury.

Worldwide, coronary heart disease (CHD) causes approximately one-third of all deaths in men and one-quarter of all deaths in women and represents a significant threat to public health. The global burden of CHD in terms of disability-adjusted life years (DALY) or " healthy years of life lost " is projected to increase from around 47 million DALY globally in 1990 to 82 million in 2020 [1]. Myocardial ischemia-reperfusion (I/R) injury is a manifestation of CHD in patients undergoing thrombolysis or percu-taneous coronary intervention (PCI) for acute myocardial infarction (AMI), patients undergoing cardiac bypass surgery, or patients surviving cardiac arrest. Novel cardioprotective strategies aimed at improving the clinical outcomes of patients with CHD by triggering intrinsic adaptive responses to protect the heart against I/R injury are increasingly needed. Prior to 1986, the concept of cardioprotection in the setting of AMI was purely theoretical. In 1986, the team of Murry et al. [2] reported a most unusual observation: several cycles of brief I/R occurred before a long coronary occlusion, named ischemic preconditioning (IPC), resulted in reduced size of myocardial infarct in canine hearts. Then Downey's laboratory made the first conceptual breakthrough in how IPC protects the heart: a brief infusion of an adenosine analogue in lieu of brief ischemia protected the heart, but treatment with an adenosine receptor antagonist abolished the protection of IPC [3]. Since then, much progress has been made in understanding the signal transduction pathways in various models and forms of cardiac protection. Of particular interest is the recent development of potential strategies for protecting the heart by ischemic postconditioning (I-Post) [4] , pharmacological preconditioning (PPC) [5,6] , remote preconditioning (RPC) [7] , or intermittent hypoxic adaptation (IHA) [8,9]. This Special Issue has highlighted research progress into novel approaches, signaling pathways and cross-talk, herbal medicine, and mitochondrial mechanisms, as well as study strategies in this exciting field of cardioprotection. The IPC phenomenon, as one intervention for protecting the ischemic heart, has been confirmed in all species examined. IPC has also been applied clinically, for patients undergoing cardiac bypass surgery or those with unstable angina. However, IPC would be impossible to implement in patients with an unpredicted onset of myocardial ischemia. Alternatively, I-Post, reported 4 years ago by Vinten-Johansen's group [4] , offers an interventional strategy that can be applied at the time of myocardial reperfusion, a target of interest for cardioprotection [10] , for AMI treated with PCI [1]. …