title: Ambient hemolysis and activation of coagulation is different between HeartMate II and HeartWare left ventricular assist devices.
abstract: BACKGROUND
  Thromboembolic and bleeding events in patients with a left ventricular assist device (LVAD) are still a major cause of complications. Therefore, the balance between anti-coagulant and pro-coagulant factors needs to be tightly controlled. The principle hypothesis of this study is that different pump designs may have an effect on hemolysis and activation of the coagulation system. Referring to this, the HeartMate II (HMII; Thoratec Corp, Pleasanton, CA) and the HeartWare HVAD (HeartWare International Inc, Framingham, MA) were investigated.
  
  
  METHODS
  For 20 patients with LVAD support (n = 10 each), plasma coagulation, full blood count, and clinical chemistry parameters were measured. Platelet function was monitored using platelet aggregometry, platelet function analyzer-100 system ( Siemens, Marburg, Germany), vasodilator-stimulated phosphoprotein phosphorylation assay, immature platelet fraction, platelet-derived microparticles, and von Willebrand diagnostic.
  
  
  RESULTS
  Acquired von Willebrand syndrome could be detected in all patients. Signs of hemolysis, as measured by lactate dehydrogenase levels (mean, 470 U/liter HMII, 250 U/liter HVAD; p < 0.001), were more pronounced in the HMII patients. In contrast, D-dimer analysis indicated a significantly higher activation of the coagulation system in HVAD patients (mean, 0.94 mg/liter HMII, 2.01 mg/liter HVAD; p < 0.01). The efficacy of anti-platelet therapy using clopidogrel was not sufficient in more than 50% of the patients.
  
  
  CONCLUSIONS
  Our results support the finding that all patients with rotary blood pumps suffered from von Willebrand syndrome. In addition, a distinct footprint of effects on hemolysis and the coagulation system can be attributed to different devices. As a consequence, the individual status of the coagulation system needs to be controlled in long-term patients.
authors.affiliation: Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany. Electronic address: ibirschmann@hdz-nrw.de.
authors.forename: Ingvild
authors.initials: I
authors.lastname: Birschmann
authors.affiliation: Department of Bioinformatics, Biocenter, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Dittrich
authors.affiliation: Institut für Laboratoriumsmedizin, Johannes Wesling Klinikum Minden, Minden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Eller
authors.affiliation: Department for Cardiothoracic-, Transplantation- and Vascular Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Wiegmann
authors.affiliation: Baxter Innovations GmbH, Vienna, Austria.
authors.forename: Armin J
authors.initials: AJ
authors.lastname: Reininger
authors.affiliation: Hämostaseologie, Medilys Laborgesellschaft mbH, Asklepios Klinik Altona, Hamburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Budde
authors.affiliation: Heart Center Leipzig, Department of Cardiac Surgery, University of Leipzig, Leipzig, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Strüber
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D001777:Blood Coagulation / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects* / Q000145:classification*; D006461:Hemolysis / Q000502:physiology*; D006470:Hemorrhage / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D012307:Risk Factors; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology; D018487:Ventricular Dysfunction, Left / Q000628:therapy*; D055815:Young Adult; D014842:von Willebrand Diseases / Q000453:epidemiology / Q000209:etiology
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors
keywords: anti-platelet drugs; aquired von Willebrand syndrome; bleeding events; left ventricular assist device; platelet function; thromboembolic event