title: Assessment of platelet function with light transmission aggregometry in 24 patients supported with a continuous-flow left ventricular assist device: a single-center experience.
abstract: OBJECTIVE
  This study evaluated platelet function for an extended period of time in patients with a HeartMate II continuous-flow left ventricular assist device (Thoratec Corporation, Pleasanton, Calif) with light transmission aggregometry and investigated the potential role of this test in clinical management.
  
  
  METHODS
  Twenty-four patients were studied prospectively after implantation. Mean duration of support was 8.5 months. Platelet functions were assessed with light transmission aggregometry induced by thrombin receptor agonist peptide, ristocetin, or arachidonic acid. All patients received an aspirin regimen that was progressively increased until arachidonic acid-triggered platelet aggregation dropped lower than 20%. Plasma levels of von Willebrand factor were also determined when ristocetin-induced platelet agglutination was impaired.
  
  
  RESULTS
  Intensity of platelet aggregation with thrombin receptor agonist peptide was little changed in patients with a HeartMate II relative to control subjects. Aspirin dose greater than 160 mg/d was progressively required in 46% of patients. Ristocetin-induced platelet agglutination was impaired in 4 patients in association with a lack of high molecular weight von Willebrand factor multimers. Three patients had thromboembolic events (12.5%) and 8 (33%) suffered from major bleeding complications.
  
  
  CONCLUSIONS
  High platelet reactivity during treatment with aspirin is common in patients with a HeartMate II. Moreover, light transmission aggregometry may detect impaired ristocetin-induced platelet agglutination, enabling dosage of aspirin to be adjusted. Our strategy showed no major improvements in terms of thrombosis rate when compared with published data, although bleeding frequency was somewhat reduced. Benefits of light transmission aggregometry testing need to be assessed in a larger randomized study with a longer follow-up.
authors.affiliation: Laboratoire d'Hématologie, CHU de Bordeaux, Pessac, France; Université Bordeaux II, Bordeaux, France; Adaptation Cardiovasculaire à l'Ischémie, INSERM U1034, Pessac, France. Electronic address: mathieu.fiore@chu-bordeaux.fr.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Fiore
authors.affiliation: Laboratoire d'Hématologie, CHU de Bordeaux, Pessac, France; Université Bordeaux II, Bordeaux, France; Adaptation Cardiovasculaire à l'Ischémie, INSERM U1034, Pessac, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: James
authors.affiliation: Laboratoire d'Hématologie, CHU de Bordeaux, Pessac, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Mouton
authors.affiliation: Université Bordeaux II, Bordeaux, France; Adaptation Cardiovasculaire à l'Ischémie, INSERM U1034, Pessac, France; Service d'Anesthésie-Réanimation II, CHU de Bordeaux, Pessac, France.
authors.forename: Joachim
authors.initials: J
authors.lastname: Calderon
authors.affiliation: Université Bordeaux II, Bordeaux, France; Adaptation Cardiovasculaire à l'Ischémie, INSERM U1034, Pessac, France; Département de Chirurgie Cardiaque, Hôpital Cardiologique du Haut-Lévêque, Pessac, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Barandon
authors.affiliation: Université Bordeaux II, Bordeaux, France; Adaptation Cardiovasculaire à l'Ischémie, INSERM U1034, Pessac, France; Service d'Anesthésie-Réanimation II, CHU de Bordeaux, Pessac, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ouattara
authors.affiliation: Unité de Traitement de l'Insuffisance Cardiaque, Hôpital Cardiologique du Haut-Lévêque, Pessac, France.
authors.forename: François
authors.initials: F
authors.lastname: Picard
mesh_terms: D000368:Aged; D016718:Arachidonic Acid; D001241:Aspirin / Q000008:administration & dosage* / Q000009:adverse effects; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D005602:France; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices / Q000009:adverse effects; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D010979:Platelet Function Tests / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D012307:Risk Factors; D012310:Ristocetin; D013923:Thromboembolism / Q000097:blood / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
chemical_list: D010975:Platelet Aggregation Inhibitors; D012310:Ristocetin; D016718:Arachidonic Acid; D001241:Aspirin