PB1294 - FIRST REPORTED CASE OF CARDIAC SURGERY IN A PATIENT WITH HEMOPHILIA B ON TREATMENT WITH ALBUTREPENONACOG ALFA (rIX-FP).

Background: Cardiac surgery poses a high hemostatic risk and is therefore considered a major challenge in hemophilia patients. Albutrepenonacog alfa (rIX-FP) is a recombinant fusion protein that binds factor IX to albumin and its administration has been shown to be safe and effective for the control of perioperative hemostasis.

Aims: We present the first case of cardiac surgery in a hemophilia B (HB) patient on treatment with rIX-FP.

Methods: Forty-eight-year-old male diagnosed with mild HB, with severe hemorrhagic phenotype, on treatment with rIX-FP (37.5IU/kg per week). Patient present with a history of smoking, dyslipidemia, HIV and HCV.

Results: Two weeks after starting rIX-FP he was diagnosed with acute coronary syndrome with ST elevation in II, III, aVF and a decrease in aVL. On admission, the patient had a trough FIX level of 27.3% (7 days since the last infusion). Coronary angiography results showed a coronary tree with severe, diffuse, calcified 3-vessel disease that could not be revascularized, so it was decided to schedule a coronary artery bypass grafting with extracorporeal circulation (ECC). One hour prior to surgery, the patient was treated with 37.5IU/kg of rIX-FP, reaching FIX levels of 86.5%. The surgery was performed without complications and was monitored by ROTEM, with levels in range and without requiring a new dose of rIX-FP until the following day. After surgery (FIX levels: 74.5%), the patient started antiplatelet therapy and FIX levels remained at ~60%. The individual pharmacokinetics showed a half-life of rFIX-FP of 135.5 hours, so it was decided to treat with 37.5IU/kg weekly, maintaining FIX levels >30%.

Conclusion(s): In a patient with hemophilia B, treatment with rIX-FP allowed cardiac surgery with ECC to be performed safely and without hemorrhagic or thrombotic complications, requiring a single pre-operative dose. The use of ROTEM proved to be useful in monitoring the patient during surgery.