The role of insulin-like growth factor during a postischemic period - new insights into pathophysiologic pathways in cardiac tissue.

Despite an improvement in the therapeutic strategies available for an acute ischemic event, cardiac disease is still the principal cause of morbidity and mortality in Western societies. A shift from acute towards more chronic heart disease due to atherosclerotic disease has been recognized. Modification of adaptive capacities of the cardiac muscle after damage remains a key component in the prevention of chronic cardiac disease, such as overt heart failure. It has recently been demonstrated that local insulin-like growth factor (IGF)-1 homeostasis in the cardiac tissue is closely involved in postischemic adaptation, such as the process of remodeling. Both experimental and clinical data support the theory that IGF-1 plays a key role in the adaptive response of the myocardium during both acute myocardial ischemia and chronic myocardial failure, regulating left ventricular remodeling and thereby restoring left ventricular architecture. This eventually leads to improvement in the function of the failing heart. While most experimental data support the beneficial role of IGF-1 in restoring architecture and function of the failing heart, clinical trials investigating the role of IGF-1 treatment of patients in cardiac failure show conflicting results. In this bench-to-bedside review, the authors aim to highlight recent advances in knowledge of the role of paracrine and autocrine IGF balances during postischemic cardiac adaptation, in order to present possible new initiatives concerning therapeutic strategies in maladaptive cardiac performance, such as the syndrome of heart failure.