**6. Conclusions**

Neurohormonal imbalance, inflammation, apoptosis, and abnormal inter and intracellular signaling and remodeling on molecular and genetic levels are critical processes contributing to adverse events in HF patients. This chapter provides a comprehensive overview of reverse remodeling on neurohormonal, myocardial, and cardiomyocyte intracellular levels in response to MCS in patients with HF. Knowledge about molecular mechanisms of underlying effects of VAD support aid to understand the adverse effects of myocardial unloading and deterioration of patients undergoing VAD therapy. While cardiac reverse remodeling has been correlated with clinical recovery in most post-VAD patients, many of those patients have deteriorated back to the original HF phenotype after LVAD explantation, suggesting the importance of considering a higher degree of myocardial recovery that may persist after device removal [169]. We found a significantly lower number of pediatric reports on clinical and pathological features of reverse remodeling compared to adult HF patients undergoing VAD support. Hence, there is a need for research on pediatric patients with VAD support, so we can better understand features of reverse remodeling specific to pediatric myocardium.
