Résumé :
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Over the past decade, there has been accumulating experimental evidence that stem cell transplantation could be a new, effective approach for repairing damaged myocardium. A surprisingly wide range of non-myogenic cell types improves ventricular function, suggesting that benefit may result in part from mechanisms that are distinct from true myocardial regeneration and are now thought to result from noncardiogenic mechanisms. Enthusiasm for cell therapy for the injured heart has already reached the clinical setting, with physicians in several countries involved in clinical trials using several cell populations. A recent meta-analysis on 10 randomized clinical trials including more than 650 patients, suggested that intracoronary cell therapy following percutaneous coronary intervention for acute myocardial infarction provides statistically and clinically relevant benefits on cardiac function and remodeling. Our incomplete understanding of the complex extra- and intracellular signaling that governs cell homing and differentiation is currently a major limitation of this technique. Clearly there are numerous technical and biological questions that are yet to be resolved regarding cell based therapies for the prevention and treatment of cardiac dysfunction including optimal cell type, timing of delivery, dosing and the mechanisms of benefit. However, an equally important challenge to the field is determining which patients may benefit from treatment. Identifying patient characteristics that enrich patient populations that benefit from cell therapy will ultimately decrease the size of clinical trials, maximize the benefit-risk ratio to patients for an invasive therapy, potentially offer insight into mechanism, and allow for efficient translation of this novel form of therapy to clinical populations, including patients with muscular dystrophies and cardiac complications.
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