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End-stage Heart FailureHM3_SnoopyNCT04641416

Noninvasive Cardiovascular Diagnosis of Patients With Fully Magnetically Levitated Blood Pumps

An observational study of End-stage Heart Failure and Cardiomyopathies, run by Thomas Schlöglhofer, PhD, MSc at 1 site in Austria.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Left Ventricular Assist Device (LVAD) therapy has become a well-established treatment option for endstage heart-failure either as a bridge to transplant (BTT) or destination therapy (DT). Read more about this study

Who is it for?
Ages 18 to 75 years
What is being tested?
Routinely performed echo, ECG and hemodynamic monitoring
How many people
60 participants
Where
1 siteAustria
Study dates
9 Jul 2020to 30 Dec 2026
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: End-stage heartfailure patients (NYHA IV), receiving a HeartMate 3 LVAD at the Medical University of Vienna either as bridge to transplant or destination therapy.

Who may be able to join

  • All patients with the HeartMate 3 system implanted at the Medical University of Vienna, which are able and willing to understand and sign the informed consent form, and which do not meet any exclusion criteria will be included.

Who cannot join

  • Age: <18 or >75 years
  • Inability to provide informed consent
  • Patients with known intraventricular or aortic root thrombus formation or known pathology of the coagulatory system. Although an intraventricular thrombus formation is usually removed intraoperatively during the LVAD implantation procedure, the rationale for this exclusion criterion is to avoid suction of such thrombus material during possible speed changes (± 20% from the initial pump speed). Consequently, the exclusion of patients with known pathology of the coagulation system, who thus have a higher risk of developing any kind of thrombus formation, is another safety measure.
  • Inaccessibility for transthoracic ultrasound diagnostics. Firstly, as described in the visit and assessment schedule (Appendix), changes in pump speed are only performed under transthoracic echo guidance. Secondly, as described above, echo parameters are required to correlate with the non-invasive CDAS pump data. Therefore, the inaccessibility of ultrasound diagnostics (e.g. due to poor image quality) is another exclusion criterion.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Austria1 site, 1 recruiting
  • Medical University of Vienna

    Vienna, 1090

    Thomas Schlöglhofer, MSc, +4314040027280, thomas.schloeglhofer@meduniwien.ac.at

    Recruiting

Other trials in Austria

About this study

Official title: Pilot Study: Noninvasive Cardiovascular Diagnosis of Patients With Fully Magnetically Levitated Blood Pumps

Left Ventricular Assist Device (LVAD) therapy has become a well-established treatment option for endstage heart-failure either as a bridge to transplant (BTT) or destination therapy (DT). Monitoring of the pump and with this the cardiac status with the HeartMate 3 (HM3) is currently very limited to infrequent log-files with one data entry every 15 minutes and only limited amount of entries. Due to the low resolution data, the standard HM3 monitoring is not feasible for the evaluation of suction events or in depth analysis of the interaction between LVAD and the remaining native heart function. Aim of this study is to develop noninvasive diagnostics of the cardiac remaining respectively recovering function derived from HeartMate 3 pump data only and compare with standard clinical diagnostic procedures. These procedures include cardiac ultrasound and ECG. After this pilot study, the newly developed methods would allow frequent, simple and automatic monitoring of patients implanted with the HeartMate 3 device. Such continuous assessment of cardiac function would massively help therapy optimization of cardiac protection and, if possible, cardiac recovery.

Read the detailed description
  1. Background Left Ventricular Assist Device (LVAD) therapy has become a well-established treatment option for endstage heart-failure either as a bridge to transplant (BTT) or destination therapy (DT). Currently, continuous flow LVADs are operated at a constant rotational speed, which results in a fixed relation between the difference between pump inlet and outlet pressure (=head pressure) and pump flowrate. This results in a cardiac support, which is not very adaptable to physiologic demand or preload changes due to reduced venous return and subsequent preload reduction e.g. due to hypovolemia. Nonetheless it could be shown, that optimal setting of LVAD support is essential to optimize patient outcomes. Proper measurement for cardiovascular function under LVAD support is therefore of key importance, especially as unwanted pumping conditions such as "overpumping", causing a collapse of structures of the left ventricle (LV), also referred to as suction. This could lead to suction induced arrhythmia (or tachycardia) as well as impairments to the right ventricle (e.g. tricuspid valve insufficiency) due to a ventricular septum shift. Ultrasound and cardiac catheterization are the standard clinical methods for the evaluation of morphological and functional properties of the heart, and also eventually changing properties of the aortic valve. Further diagnostics include conventional ECG analysis but also heart rate variability to obtain information of the neurohumoral status. Exercise stress tests and recently developed activity diagnostics give further important information about overall recovery and quality of life. All these methods however require time-consuming procedures, being unacceptably cumbersome for frequent monitoring. On the other hand, a frequent and effective noninvasive evaluation of the cardiac status provided by the rotary blood pump (RBP) itself would have a remarkable impact on LVAD patients and their therapy, especially for the evaluation of their overall and cardiac recovery. Previously, pump signals from another centrifugal blood flow device (HVAD Medtronic Inc., Minneapolis, USA) have been used to estimate hemodynamic variables noninvasively. These were used to track patient progress, or to detect unwanted pumping states, such as ventricular suction. Variables such as contractility, relaxation, suction, Aortic Valve Opening and cardiac rhythms, can be extracted. These may aid clinicians in their decisions on the level and strategy of pump support. While this is not currently widely implemented in clinical practice, this type of monitoring holds the promise of deeper insights into patient physiology. As demonstrated in a recent study, continuous high-resolution HVAD monitoring sheds light on suction occurrences. Interindividual and intraindividual characteristics of longitudinal suction rates were observed. Longer suction clusters have higher probabilities of tachycardia within the cluster and more severe types of suction waveforms. This work showed the necessity of improved LVAD data monitoring. The Abbott Inc. HeartMate 3 LVAD is a centrifugal continuous flow pump with a fully magnetically levitated rotor enabling frictionless movement, textured blood-contacting surfaces to establish a tissue interface with blood and wide blood flow gaps between the rotor and its housing to lower shear stress and consequently blood trauma. Monitoring of the pump and with this the cardiac status with the HeartMate 3 is currently very limited to infrequent log-files with one data entry every 15 minutes and only limited amount of entries. Due to the low resolution data, the standard HM3 monitoring is not feasible for the evaluation of suction events or in depth analysis of the interaction between LVAD and the remaining native heart function.
  2. Aim The aim of this study is to develop noninvasive diagnostics of the cardiac remaining respectively recovering function derived from HeartMate 3 pump data only and compare with standard clinical diagnostic procedures. These procedures include cardiac ultrasound and ECG. After this pilot study, the newly developed methods would allow frequent, simple and automatic monitoring of patients implanted with the HeartMate 3 device. Such continuous assessment of cardiac function would massively help therapy optimization of cardiac protection and, if possible, cardiac recovery.
  3. Study protocol The developed new methods are based on pump flow, pump motor and magnetic levitation data only. These methods include also the evaluation of heart rate variability and arrhythmias and its influence to HeartMate 3 suction events. In this study non-invasive recordings of pump data will only be performed at rest, with speed changes under guidance of echocardiography on occasion. Beat-to-beat/High resolution pump data recordings for the HeartMate 3 have not been performed before, thus the recorded pump data will be analyzed and compared to clinical diagnostics in this pilot study. Previous feasibility and safety tests for the pump data recording have been performed in the laboratory setting. The pump data recording is used for research only as observational study and not for diagnostic purposes. The pickup of high resolution data is done with a coil mounted outside on the driveline with only one contact (common ground) to the exposed metal housing of the driveline connector. Therefore, the only metal connection will be this equipotential bonding conductor connection to the outside of the metal housing of the driveline connector. The pickup coil is only listening to the magnet field of the wires transferring data packages between pump and peripheral controller. During the study there is no need to exchange the existing peripheral LVAD HeartMate 3 controller, therefore at no point the pump will be stopped. The data of patients on the intensive care unit (ICU) or normal ward are stored in a continuous data acquisition system (CDAS) on a notebook which is operated in battery operation, and analyzed afterwards with a mat-lab (MathWorks Inc., USA) based software. For outpatients a mobile data-recorder (size of approximately 8cm x 5cm x 2cm, weight approx. 110g) powered with a 9V battery will allow a continuous data acquisition for a period up to 2 months on a SD card. Routinely, all pump parameters are stored in a so-called log file, in the form of delimiter-separated character strings containing decimal and hexadecimal values. The log file data is provided from the pump's controller and the pump itself, which are both storing a periodical and an event log file. The periodical log files, as the name implies, are created continuously and periodically during pump operation, while the event log files provide additional information which is stored only when the HeartMate 3 detects a potential adverse event or abnormal pump behavior (e.g. arrhythmias, suction). Therefore, the data of every patient is contained in multiple sets of four different log files (periodical and event log files from the pump's controller, plus periodical and event log files from the pump itself) with defined timestamps for each set of parameters. The maximal storage capacity of logfiles is only 256 entries with a minimal periodic logging interval of 10min. Therefore the ability to detect e.g. suction events and abnormal pump operation due to hemodynamically changes should be evaluated with high resolution continuous data acquisition system (CDAS) data and the routinely available logfiles and compared to each other. Pump data will be collected from the routinely available logfiles via the device monitor and from high resolution HeartMate 3 CDAS data, which can be picked up contactless every second. The data of patients on the ICU or normal ward are stored in a continuous data acquisition system (CDAS) on a notebook which is operated in battery operation, and analyzed afterwards with a mat-lab based software. For outpatients a mobile data-recorder will allow a continuous data acquisition for a period up to 2 months on a SD card. During the post-operative patient stay at the ICU and normal ward, the pump data will be continuously recorded together with all routinely measured hemodynamic variables. Contextually with the pump data, during the post-operative patient stay at the ICU and normal ward, ECG will be continuously acquired from the clinical monitors. Holter ECG data are recorded once for 24 hours during the normal ward stay and once at home after the outpatient visit 12 months after enrollment. The application of the Holter ECG device and the pump data measurement will be performed during the hospital stay or at home thus requiring no additional patient waiting time. Additionally, for patients with implanted pacemakers/ICDs or loop recorders, the heart rate and variability parameters will be also retrieved from the data delivered by these devices (of course, only if the setting of the pacemakers/ICD allows changes in the patient individual heart rate). ECG will be recorded using the clinical monitors during the stay on the ICU and using Holter ECG devices for ambulant patients and in out of hospital patients. SPSS and descriptive statistics will be applied. The standard heart rate variability parameters and more sophisticated parameters for arrhythmia pattern detection which are derived from the pump flow and the same parameters derived from the ECG signals or if applicable and available from implanted pacemakers/ICDs and loop recorders will be described explorative based on mean ± standard deviation or median (interquartile range) and visually represented by histograms and box-plots. However, these only have a purely exploratory character in this pilot study to check the feasibility and/or practicability of this non-invasive methods and for a later, larger study to find possible correlations, which should also be checked in a follow-up study. Following this pilot study, a follow-up study should test the hypothesis that the developed methods for easy assessment of cardiac function during LVAD support, can provide an additional tool for optimization of cardiac protection, thereby reducing adverse events and optimizing clinical outcomes.
  4. Summary Currently, studies of recovery of heart and body function are complex, time-consuming and can only be carried out on a case-by-case basis. Aim of this study is the continuous determination of cardiovascular parameters from the already non invasively available pump data from fully magnetically supported cardiac support systems (HeartMate 3, Abbott Inc.). In this project these analysis methods are to be applied clinically and compared with established examinations (e.g. ultrasound, ECG). With the newly developed biomedical method, a regular, high-resolution and cost-effective pump monitoring, which further improves life expectancy and quality of life of LVAD patients should be established.
Being tested
Routinely performed echo, ECG and hemodynamic monitoring
Keywords
ventricular assist device, non-invasive monitoring
Medical subject headings
Cardiomyopathies

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Routinely performed echo, ECG and hemodynamic monitoringDiagnostic test

    The pump data of patients on the ICU or normal ward are stored in a continuous data acquisition system (CDAS) on a notebook which is operated in battery operation, and analyzed afterwards with a mat-lab based software. For outpatients a mobile data-recorder will allow a continuous data acquisition for a period up to 2 months on a SD card. During this non-invasive pump data monitoring, routinely available hemodynamic monitoring, ECG and echo data will be collected.

Study groups in NCT04641416
Study groupRoleWhat they receive
Noninvasive pump monitoringAll patients with the HeartMate 3 system implanted at the Medical University of Vienna, which are able and willing to understand and sign the informed consent form, and which do not meet any exclusion criteria will be included.
Receives: Diagnostic Test: Routinely performed echo, ECG and hemodynamic monitoring

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of suction events and suction burden (percentage number of suction operation in relation to normal operation) evaluated using routinely available HeartMate 3 log files and high-resolution CDAS data

    The incidence of suction events and suction burden due to hemodynamically changes during follow-up will be evaluated with high resolution continuous data acquisition system (CDAS) data and the routinely available HeartMate 3 logfiles and compared to each other.

    Null hypothesis: There is no difference in the incidence of suction events and suction burden assessed by routinely available HeartMate 3 log files and high-resolution CDAS data.

    Measured: 2 years

Secondary outcomes (1)
  1. Change of left ventricular unloading during pump speed changes (+- 20% from baseline speed)

    Change of left ventricular unloading as assessed by routinely performed hemodynamic monitoring (pulmonary capillary wedge pressure), echocardiography (left ventricular dimensions at end-systole and diastole) and non-invasive CDAS peak-to-peak pump flow. Correlation of left ventricular unloading measures (echo dimensions and pulmonary capillary wedge pressure) with the non-invasive peak-to-peak pump flow under investigation using Spearman and Pearson correlation coefficients (depending of the probability density function of the dataset) and graphical representation of the pair-wise correlations is done by means of a scatter diagram.

    Null hypothesis: There is no difference in the change of left ventricular unloading as assessed by pulmonary capillary wedge pressure, left ventricular dimensions at end-systole and diastole, and non-invasively assessed CDAS peak-to-peak pump flow.

    Measured: at post operative day 3, hospital discharge and at 6 months following hospital discharge

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Nov 2020
  2. Study start9 Jul 2020
  3. Primary completion15 Dec 2026 (estimated)
  4. Study completion30 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04641416
Sponsor's protocol ID
EK Nr: 1251/2020
Acronym
HM3_Snoopy
Status last verified
May 2026
First submitted
28 Jul 2020
Last updated
8 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • (1.) T. Imamura et al. Optimal Hemodynamics during Left Ventricular Assist Device Support Are Associated with Reduced Readmission Rates. Circ. Hear. Fail., vol. 12, no. 2, pp. 1-11, 2019. (2.) M. Vollkron, et al. Suction Events During Left Ventricular Support and Ventricular Arrhythmias. J. Hear. Lung Transplant., vol. 26, no. 8, pp. 819-825, 2007. (3.) Moscato F, et al. Evaluation of Left Ventricular Relaxation in Rotary Blood Pump Recipients Using the Pump Flow Waveform: A Simulation Study. Artif Organs 2012; 36:470-478 (4.) M. Vollkron, et al. Development of a suction detection system for axial blood pumps. Artif. Organs, vol. 28, no. 8, pp. 709-716, 2004. (5.) Moscato F, et al. Continuous monitoring of cardiac rhythms in left ventricular assist device patients. Artif Organs 2014; 38:191-198 (6.) Gross C, et al. Continuous LVAD monitoring reveals high suction rates in clinically stable outpatients. Artif Organs. 2020 Jan 16. doi: 10.1111/aor.13638. [Epub ahead of print]

Questions about this trial

What is this clinical trial studying?

An observational study of End-stage Heart Failure and Cardiomyopathies, run by Thomas Schlöglhofer, PhD, MSc at 1 site in Austria.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Thomas Schlöglhofer, MSc (+4314040027280, thomas.schloeglhofer@meduniwien.ac.at), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of suction events and suction burden (percentage number of suction operation in relation to normal operation) evaluated using routinely available HeartMate 3 log files and high-resolution CDAS data (time frame: 2 years). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04641416, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.

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