Human/Machine Interface: What the HeartMate 3 ® Device Tells Us About the Future

Specific Aims The prevalence of heart failure (HF), a chronic medical condition, continues to grow exponentially, affecting more than 26 million globally. There are more than 6.5 million in the United States alone with HF. Roughly 600,000 individuals suffer from end-stage HF, defined as advanced structural changes to the heart, significantly worsening HF symptoms despite medical therapy, and generally more than 50% 1-year mortality risk.There are limited treatment options once traditional guideline driven medical therapy fails in those advancing to end-stage HF. Limited treatment options at this point have included consideration of cardiac transplantation or implantation of a durable left ventricular assist device (dLVAD), or proceeding down the path of palliative care and hospice. One-year mortality risk without a dLVAD is nearing now 80%, as opposed to one-year survival with a dLVAD approaching 75-80%. Once a dLVAD is placed, concern continues of predicting adverse events. Multiple groups have utilized different strategies to predict the risk of bleeding, stroke and infection, yet not one strategy alone is all-encompassing of these three adverse events. Bleeding risk following dLVAD implantation ranges between 15-68%, while the risk of infection is estimated between 19-39%. The risk of stroke with dLVADs is as high as 10%. Prior to market removal, researchers utilizing the HeartWare ® (or HVAD) have analyzed waveform and pump data to predict or determine sequencing of adverse events. This study through machine learning, found that bleeding and right heart failure (RHF) were the most commonly found adverse events with the earliest onset, while infection and bleeding were the most common adverse events overall after three months on device. While additional pump data analyses exist for other centrifugal flow pumps, there is a significant gap in the literature where little information is known of how the HeartMate 3 ® dLVAD pump operations data (such as suction events, low flow alarms and other adventitious alarms, PI events and incidence of power cable disconnects greater than 20 seconds) interfaces with quality of life (QOL), frailty and other various medical conditions, as well as how additional pump data may predict future adverse events such as gastrointestinal bleeding (GIB), RHF, infection, hypertension, arrhythmias or stroke. Clinicians caring for individuals with a HeartMate 3 ® devices are not aware at this time how pump operations data correlates to the clinical component of care, thus demonstrating the importance of this study.

To address the gap of how the HeartMate 3 ® dLVAD pump data interfaces with clinical care, this prospective, multi-center trial will analyze the normal and abnormal pump operations data (such as suction events, low flow alarms and other adventitious alarms, PI events or incidence of power cable disconnects) from HeartMate 3 ® dLVADs for clinical correlations to QOL, severity of frailty, various medical conditions, and adverse events at ten different centers worldwide. Currently there are no mandatory guidelines for pump operations data downloads in the instructions-for-use manual, only recommendations from each individual company. Researchers have been challenged to think outside the box of what information has yet to be divulged from normal and abnormal pump operations in order to assist clinicians in better care as the evolution of smaller and smarter to devices occur. In this study, the investigators hypothesize the following: 1.) there will be correlations between abnormal hemodynamic pump operations (e.g. suction events, low flow alarms and other adventitious alarms, "PI" events, and power cable disconnects greater than 20 seconds), and worsening quality of life; 2.) worsening severity of frailty will demonstrate increased power cable disconnects and/or increased use of the power module "A/C" power, due to handling mistakes or less mobility; 3.) early stages of gastrointestinal bleeding will be seen with abnormal hemodynamic pump operations (such as suction events) 3-7 days prior to the actual event of being symptomatic; and 4.) patients with GIB or RHF will have lower PI values in comparison to those that do not have adverse events, when having comparable set speeds. In order to meet the objectives with the purpose of this study, two aims have been established:

Aim #1: Evaluate the effectiveness of HeartMate 3 ® dLVAD normal and abnormal pump operations data on clinical practice applications when utilizing downloadable pump data analyses at several time points following implantation: discharge from the intensive care unit (ICU), discharge from the hospital (minimum over a week post implant and +/- 3 days from discharge), 3-months post dLVAD, 6-months post dLVAD, and 12-months post dLVAD. Data will also be collected during any unplanned office visits, any admission regardless of the reason, unplanned Emergency Room (ER) visits related to equipment problems or any serious adverse event related ER visits. Clinical practice applications include: QOL, severity of frailty and other various medical conditions, and adverse events such as GIB, RHF, infection, hypertension, arrhythmias and stroke.

Aim #2: Evaluate correlations and relationships between longitudinal normal and abnormal dLVAD pump operations data, to demographic and clinical variables (e.g. age, gender, length of stay, Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) score, co-morbidities, eyeball frailty test, laboratory values, EQ-5D and Visual Analog Scale, Mini-Cog ©, physical frailty measurements through 6-Minute Walk Test and Sit-to-Stand Chair rise test, anticoagulation strategies, cardiopulmonary bypass time, intubation to extubation time, temporary support prior to and following dLVAD implantation, concomitant surgeries, post-surgical complications, and echocardiography results).

Significance Individuals caring for HeartMate 3 ® dLVAD recipients oftentimes rely on industry interpretation of waveforms and pump data in urgent clinical situations. However, there may be limitations in how quick this information is provided to the clinicians to piece the puzzle together. There is limited pump operations data research directly available to the clinician to demonstrate the interface connection towards clinical practical applications, or relationships with other co-morbid conditions and adverse events as previously mentioned. With persistent adverse events in the dLVAD population, more information pertaining to the clinical situation is always helpful. There has only been data reported on the Heartware ® system with regards to real time data. For example, HeartWare ® log files and pump operations data have been analyzed to identify ingestion of pump thrombosis, while suggestions have begun to start using patient monitoring through the HeartMate 3 ® dLVAD system. To date, there is scarce literature to describe the HeartMate 3 ® dLVAD pump operations data within the clinical interface. More importantly, clinicians are not aware of added benefits from dLVADs unless shared from industry partners.