Monitoring tools to optimize therapy in patients with implantable left ventricular assist devices

Implantable mechanical circulatory support systems, known as left ventricular assist devices (LVADs), provide long-term, life-saving cardiac support to patients with end-stage heart failure (HF). With the current state of the art, the devices used to quantify a patient's medical HF therapeutics and their interactions of the LVAD with the cardiovascular system are not well studied. Therefore, this paper presents the results with a novel method using the LVAD pump as a sensor. The LVAD system used in this study is the Abbott HeartMate 3 (HM3), currently in clinical use. This observational work aims to establish a link between the HM3 pump data collected non-invasively and the hemodynamic data obtained in the intensive care unit (ICU). The novel longitudinal patient data obtained from the HM3 were analysed together with medical data from routine monitoring, such as invasive and non-invasive hemodynamics recorded in the ICU of the Medical University of Vienna, Vienna General Hospital. The main results obtained as linear regression models linking hemodynamics and flow pump data are described as coefficients of determination: R_adj^2=0.1949 in min flow-CVP, 0.3645 in min flow-MAP, 0.2741 in min flow-HR, 0.1800 in mean flow-CVP, 0.3415 in mean flow-MAP, 0.2992 in mean flow-HR, 0.1637 in max flow-CVP, 0.1896 in max flow-MAP, and 0.2705 in max flow-HR. Dividing the hemodynamic parameters into categories to examine data availability, for HR, 50% of the available data points were included in patients overall between HR&#8805;80bpm and HR<110bpm; for MAP, 69% between MAP&#8805;70mmHg and MAP<90mmHg; for 47% within CVP&#8805;6mmHg and CVP<12mmHg. In conclusion, this study shows that the HM3 pump as a sensor has the potential to provide a detailed overview of the patient's hemodynamic status. More in-depth analyses could follow this work, which could serve as a starting point for a new hypothesis on the use of the mechanical heart pump.