Identifying and Facilitating Ventricular Recovery on Mechanical Support

机械左心室辅助装置（LVAD）通常是严重心力衰竭患者的救生设备。 虽然LVAD通常用作移植的桥梁，但LVAD患者的重要子集 LV功能恢复，成功取出器械。LV功能评估， 由于复杂的卸载效应，常规临床手段难以或不可能用于LVAD。因此我们 已经开发了新的LV功能（前负荷调整的最大功率）的负荷无关测量方法， 在线数字超声心动图和无创动脉压。我们已经将这些方法应用于53个 选择LVAD患者，并在14例成功移除LVAD的患者中确定LV恢复。这项建议 使用由3个专家LVAD中心组成的多中心联盟：匹兹堡大学，将领导所有 宾夕法尼亚州立大学好时分校和马里兰州大学。匹兹堡大学的团队是一个 心脏成像、心力衰竭和临床人工心脏计划的合作， 卡内基梅隆大学的生物工程专家。目标1将测试我们的新的负载无关的假设， 在175-200例LVAD患者中，LV功能测量可以可靠地识别LV恢复。 常规临床峰值运动耗氧量和右心导管检查的预测能力将 进行比较，以完善LVAD移除的选择标准。具体目标#2和#3将检验假设 LVAD可以促进LV恢复：目标#2将使用体外和体内动物实验来完善 并测试同步LVAD操作的反馈控制器，以实现最佳负载，从而促进LV恢复。 目标3将在一项前瞻性多中心随机临床试验中测试该策略，其中LVAD同步 将自适应起搏与常规异步LVAD操作进行比较。 左心室辅助装置（LVAD）的机械支持可以挽救生命， 严重心力衰竭患者，通常作为移植的桥梁。虽然患者可能有心脏 在LVAD期间恢复，并且可以移除器械，因此难以使用常规方法进行评估。我们将 使用新的非侵入性心脏测试来识别LVAD的心脏恢复，并开发独特的 控制系统，以促进心脏恢复。这种同步自适应扩展策略将 使用计算机模型和动物实验开发，然后将在一个随机的多中心测试， 临床试验，以提高效率和频率的心脏恢复LVAD。

The mechanical left ventricular assist device (LVAD) is often life-saving for patients with severe heart failure. Although LVAD is typically used as a bridge to transplantation, an important subset of patients on LVAD have recovery of LV function leading to successful removal of the device. Assessment of LV function by routine clinical means is difficult or impossible on LVAD due to complex unloading effects. Accordingly, we have developed novel load-independent measures of LV function (preload adjusted maximal power) using on-line digital echocardiography and non-invasive arterial pressure. We have applied these methods to 53 selected LVAD patients, and identified LV recovery in 14 who had successful LVAD removal. This proposal uses a multi-center consortium of 3 expert LVAD centers: the University of Pittsburgh, which will lead all aspects, Penn State-Hershey, and the University of Maryland. The University of Pittsburgh team is a collaboration of cardiac imaging, heart failure and the clinical Artificial Heart Program along with bioengineering experts at Carnegie Mellon University. Aim # 1 will test the hypothesis that our novel loadindependent LV functional measures can reliably identify LV recovery in a series of 175-200 LVAD patients. The predictive power of routine clinical peak exercise oxygen consumption and right heart catheterization will be compared to refine selection criteria for LVAD removal. Specific Aims # 2 and #3 will test the hypothesis that LV recovery on LVAD can be facilitated: Aim #2 will use in vitro and in vivo animal experiments to refine and test a feedback controller for Synchronized LVAD operation for optimal loading to facilitate LV recovery. Aim #3 will test this strategy in a prospective multi-center randomized clinical trial where LVAD Synchronized Adaptive Reloading will be compared to routine Asynchronous LVAD operation. Lav Summary: Mechanical support with a left ventricular assist device (LVAD) can be life-saving for patients with severe heart failure, usually as a bridge to transplantation. Although patients may have cardiac recovery while on LVAD and the device can be removed, it is difficult to assess using routine means. We will use novel non-invasive cardiac testing to identify recovery of the heart on LVAD and develop a unique control system to facilitate cardiac recovery. This Synchronized Adaptive Reloading strategy will be developed using computer models and animal experiments, and will then be tested in a randomized multicenter clinical trial to improve both the efficiency and frequency of cardiac recovery on LVAD.