Repeated Remote Ischemic Postconditioning Protects Against Adverse Left Ventricular Remodeling and Improves Survival in a Rat Model of Myocardial Infarction Short Communication

Rationale: Remote ischemic conditioning induced by repeated episodes of transient limb ischemia is a clinically applicable method for protecting the heart against injury at the time of reperfusion. Objective: To assess the effect of chronic, repeated, remote conditioning on infarct size and long-term remodeling after myocardial infarction. D espite the timely application of reperfusion therapy, survivors of acute myocardial infarction (MI) are at significant risk from later myocardial remodeling, leading to the development of heart failure and elevated risk of death during 5-year follow-up. 1,2 It is generally agreed that the acute inflammatory process that occurs early after acute MI (a prerequisite for adequate healing and scar formation 3) can be adverse if persistent in the later post-MI recovery period. Continued oxidative stress results in proinflammatory cyto-kine release, cardiomyocyte apoptosis, ventricular fibrosis, and hypertrophy. 4 Remote ischemic conditioning reduces infarct size when applied both before (preconditioning) and during (percon-ditioning) experimental and clinical MI. 5,6 Similarly, local postconditioning can reduce infarct size. 7 Clinically, post-conditioning is achieved by repeated inflation and deflation of the angioplasty balloon after emergency coronary intervention. 8 It is now known that postconditioning can be induced experimentally and in humans, remotely, using a transient limb ischemia stimulus identical to that of remote pre-and preconditioning, and in a recent study, remote postconditioning was more effective than local postcondi-tioning in experimental MI 9. We have shown that repeated daily remote conditioning by limb ischemia leads to significant downregulation of neutrophil activation and proinflammatory responses in humans. 10 Thus, in the present study we investigated (1) whether a single episode of remote perconditioning protects against late remodel-ing; (2) whether a further decrease in infarct size or improved remodeling can be achieved when chronic re