Hemodynamic Regulation with Minimization of Myocardial Oxygen Consumption via Drugs and Left Ventricular Assist Device.

A left ventricular assist device (LVAD) reduces the burden on the heart and contributes to improving the prognosis for heart failure and myocardial infarction. However, simultaneous multi-dimensional hemodynamic regulation and myocardial oxygen consumption minimization using both drugs and devices has been a challenge primarily due to the difficulties caused by the intricate interrelation of multiple inputs, outputs, and cardiovascular factors. Extending our two-degree-of-freedom hemodynamic controller, this paper proposes a control system that integrates multiple therapeutic drugs and an LVAD as inputs to regulate three-dimensional hemodynamics while minimizing myocardial oxygen consumption. First, the LVAD's interaction with the cardiovascular system is analyzed, deriving the model for myocardial oxygen consumption during LVAD use. Next, a new optimal control framework is proposed that explicitly considers LVAD interaction. The new features of this framework are minimizing myocardial oxygen consumption, regulating three-dimensional hemodynamics, considering cardiovascular mechanics such as drug infusion modeling and a generalized circulatory equilibrium framework, and avoiding suction caused by the LVAD. The simulation results successfully demonstrated that the desired circulatory control was achieved even for patient models who are difficult to treat with medication alone by actively utilizing the LVAD while reducing the dose of the positive inotropes so as to minimize myocardial oxygen consumption.Clinical relevance - An underlying trade-off between hemodynamic stabilization and minimizing myocardial oxygen consumption makes therapeutic decision-making difficult for physicians. The proposed technique can be translated to recommend control inputs for drugs and equipment to obtain the desired treatment outcomes, thus supporting physicians' decision-making.