Preoperative Use of Romiplostim in Thrombocytopenic Patients Undergoing Cardiac Surgery.

Inclusion Criteria: * Adult patients with no upper age limit, * Scheduled cardiac surgery with cardiopulmonary bypass, * Patients with preoperative thrombocytopenia strictly \<150,000/mm3 * Surgery performed with a blood recovery system using centrifugation (Cell Saver type) or equivalent, * Feasibility of a first injection (Romiplostim or Placebo) between D-14 and D-10 before surgery, * Surgery requiring the administration of antiplatelet and/or anticoagulant therapy for a minimum of 1 month postoperatively. Exclusion Criteria: * Inability to administer the first injection of Romiplostim or Placebo within 10 days prior to surgery, * Cardiac surgery without cardiopulmonary bypass, * Coronary artery bypass grafting due to one or more significant coronary stenoses, * Tangential filtration blood recovery system (i-SEP SAME® type) planned for intraoperative use or absence of intraoperative blood recovery system due to investigator choice or availability issues, * Planned use of aprotinin as an antifibrinolytic agent during surgery, * Patient with contraindication to discontinuation of all antiplatelet therapy before surgery (with discontinuation at least 3 days before surgery for acetylsalicylic acid and at least 5 days before surgery for clopidogrel/ticagrelor), * Hereditary or acquired thrombophilia with or without a history of thrombosis, * History of ischemic or hemorrhagic stroke, * History of phlebitis, pulmonary embolism, or portal vein thrombosis, * History of heart attack with stent placement less than one year ago, * Current limb immobilization (e.g., plaster cast for ankle fracture) or inability to walk independently due to limited mobility (e.g., paralysis), * Current immobilization of a limb (e.g., plaster cast for ankle fracture) or inability to walk independently due to motor limitation (e.g., complete paralysis of a limb) or medical contraindication (e.g., strict bed rest required), * Myelogram indicating malignant hematological disease or blast cells strictly greater than 5%, * Malignant diseases with last follow-up indicating disease progression, * Severe chronic liver disease with a CHILD-PUGH score \> 6 (measured without decompensation), * Treatment with thrombopoietin receptor agonist received within 3 months prior to inclusion, * Treatment with JAK2 inhibitor currently underway or within the last month, * Treatment with Rituximab within the last 7.5 months or intravenous immunoglobulin within the last 40 days, * Ongoing treatment with corticosteroids at doses equal to or greater than 20mg of hydrocortisone, 5mg of prednisone/or prednisolone, 4mg of methylprednisone, or 0.75mg of dexamethasone, * Known hemophilia, * Hypersensitivity to romiplostim or any of its excipients, or to proteins derived from E. coli, * Context of hyperchloremia, hypernatremia, or major water and salt retention with anasarca refractory to medical treatment, * Pregnant women or women of childbearing age who are not using effective contraception, * Currently using combined oral contraceptive pills or oral hormone replacement therapy containing estrogen, * Breastfeeding women, * Minors, * Adults under guardianship, curatorship, or judicial protection, * Patients who do not speak French, * Patients without Social Security coverage.