Effects of the continuous flow left ventricular assist device (LVAD) on myocardial oxidative stress and vascular function.

摘要

Heart failure (HF) in the United States affects more than 5 million people and causes over 250,000 deaths annually. Cardiac transplantation is the best clinical treatment for end stage HF, but many patients will not survive while waiting for the next available donor heart. The introduction of the left ventricular assist device (LVAD) has improved the survival rate of HF subjects and is a commonly used mechanical device for bridging a patient to cardiac transplantation. There are two basic types of LVADs, the first generation pulsatile flow LVAD and the second generation of continuous flow LVADs. Both the pulsatile and continuous flow LVAD have been shown to improve survival rates, improve myocardial protein remodeling, and allow for an improved quality of life for HF patients. Despite these improvements, changes in myocardial oxidative stress and changes in vascular function need further examination.;A study by Amir et al. compared flow mediated endothelial-dependent dilation in patients placed with either a pulsatile or continuous flow LVAD before and after surgery. Although the pulsatile device was shown to greatly improve vascular function, this device has been phased out by the smaller and more mechanically reliable continuous flow LVAD. Little research has been conducted on the continuous flow LVAD in regards to vascular function and with many LVAD recipients awaiting a cardiac transplantation, prior adequate vascular function is important for decreasing morbidity and mortality following cardiac transplantation. The results of the following studies are designed to provide information regarding the effects of continuous flow LVAD support on myocardial oxidative stress, carotid elasticity measurements, and brachial artery vascular function in hopes of providing a basis for further research and allowing for further advancements in HF treatment.