title: Identification and Management of Pump Thrombus in the HeartWare Left Ventricular Assist Device System: A Novel Approach Using Log File Analysis.
abstract: OBJECTIVE
  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.
authors.affiliation: Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York. Electronic address: ujorde@montefiore.org.
authors.forename: Ulrich P
authors.initials: UP
authors.lastname: Jorde
authors.affiliation: Division of Cardiovascular Medicine and Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Keith D
authors.initials: KD
authors.lastname: Aaronson
authors.affiliation: MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC.
authors.forename: Samer S
authors.initials: SS
authors.lastname: Najjar
authors.affiliation: Division of Cardiovascular Medicine and Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Francis D
authors.initials: FD
authors.lastname: Pagani
authors.affiliation: Heart Lung Clinic, St. Vincent's Hospital, Sydney, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hayward
authors.affiliation: Department of Surgery, Division of Cardiac Surgery, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Zimpfer
authors.affiliation: Department of Surgery, Division of Cardiac Surgery, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schlöglhofer
authors.affiliation: Heart Failure and Cardiac Transplantation Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Duc T
authors.initials: DT
authors.lastname: Pham
authors.affiliation: Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Goldstein
authors.affiliation: HeartWare Inc., Framingham, Massachusetts.
authors.forename: Katrin
authors.initials: K
authors.lastname: Leadley
authors.affiliation: HeartWare Inc., Framingham, Massachusetts.
authors.forename: Ming-Jay
authors.initials: MJ
authors.lastname: Chow
authors.affiliation: HeartWare Inc., Framingham, Massachusetts.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Brown
authors.affiliation: Department of Cardiology, University of Chicago Medicine, Chicago, Illinois.
authors.forename: Nir
authors.initials: N
authors.lastname: Uriel
mesh_terms: D002986:Clinical Trials as Topic; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006333:Heart Failure / Q000628:therapy*; D016027:Heart Transplantation; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D013927:Thrombosis / Q000188:drug therapy* / Q000209:etiology*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: HeartWare ventricular assist device; pump thrombosis; thrombolytics; thrombus; tissue plasminogen activator