Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis

Ulrich P Jorde; Keith D Aaronson; Samer S Najjar; Francis D Pagani; Christopher Hayward; Daniel Zimpfer; Thomas Schlöglhofer; Duc T Pham; Daniel J Goldstein; Katrin Leadley; Ming-Jay Chow; Michael C Brown; Nir Uriel

doi:10.1016/j.jchf.2015.06.015

Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis

JACC Heart Fail. 2015 Nov;3(11):849-56. doi: 10.1016/j.jchf.2015.06.015. Epub 2015 Oct 7.

Authors

Affiliations

¹ Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York. Electronic address: ujorde@montefiore.org.
² Division of Cardiovascular Medicine and Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
³ MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC.
⁴ Heart Lung Clinic, St. Vincent's Hospital, Sydney, Australia.
⁵ Department of Surgery, Division of Cardiac Surgery, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
⁶ Heart Failure and Cardiac Transplantation Center, Tufts Medical Center, Boston, Massachusetts.
⁷ Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York.
⁸ HeartWare Inc., Framingham, Massachusetts.
⁹ Department of Cardiology, University of Chicago Medicine, Chicago, Illinois.

PMID: 26454842
DOI: 10.1016/j.jchf.2015.06.015

Abstract

Objectives: The study sought to characterize patterns in the HeartWare (HeartWare Inc., Framingham, Massachusetts) ventricular assist device (HVAD) log files associated with successful medical treatment of device thrombosis.

Background: Device thrombosis is a serious adverse event for mechanical circulatory support devices and is often preceded by increased power consumption. Log files of the pump power are easily accessible on the bedside monitor of HVAD patients and may allow early diagnosis of device thrombosis. Furthermore, analysis of the log files may be able to predict the success rate of thrombolysis or the need for pump exchange.

Methods: The log files of 15 ADVANCE trial patients (algorithm derivation cohort) with 16 pump thrombus events treated with tissue plasminogen activator (tPA) were assessed for changes in the absolute and rate of increase in power consumption. Successful thrombolysis was defined as a clinical resolution of pump thrombus including normalization of power consumption and improvement in biochemical markers of hemolysis. Significant differences in log file patterns between successful and unsuccessful thrombolysis treatments were verified in 43 patients with 53 pump thrombus events implanted outside of clinical trials (validation cohort).

Results: The overall success rate of tPA therapy was 57%. Successful treatments had significantly lower measures of percent of expected power (130.9% vs. 196.1%, p = 0.016) and rate of increase in power (0.61 vs. 2.87, p < 0.0001). Medical therapy was successful in 77.7% of the algorithm development cohort and 81.3% of the validation cohort when the rate of power increase and percent of expected power values were <1.25% and 200%, respectively.

Conclusions: Log file parameters can potentially predict the likelihood of successful tPA treatments and if validated prospectively, could substantially alter the approach to thrombus management.

Keywords: HeartWare ventricular assist device; pump thrombosis; thrombolytics; thrombus; tissue plasminogen activator.

MeSH terms

Clinical Trials as Topic
Fibrinolytic Agents / administration & dosage*
Heart Failure / therapy*
Heart Transplantation*
Heart-Assist Devices / adverse effects*
Humans
Thrombosis / drug therapy*
Thrombosis / etiology*
Tissue Plasminogen Activator / administration & dosage*
Treatment Outcome

Substances

Fibrinolytic Agents
Tissue Plasminogen Activator