The purpose of this study is to demonstrate that Fibrinogen Concentrate (Human)(FCH) can reduce the amount of donor blood products needed during complex cardiovascular surgery, and that it is safe and well tolerated. Subjects in this study will get either a FCH or placebo infusion during surgery. This will be in addition to the standard treatment, which is donor blood or blood products. Placebo does not contain any effective medicine.

The study is randomised. This means that the likelihood that subjects will get FCH or placebo is 50%. To make the comparison between FCH and placebo as fair as possible, the study is "double blind". This means that neither the subjects nor the study doctor will know if FCH or placebo is administered. If necessary, the study doctor can find out which treatment the subjects are receiving.

Inclusion Criteria:

At Screening:

• Undergoing elective open surgical procedures on any part of the aorta requiring cardiopulmonary bypass (CPB), with or without other cardiac surgical procedures (e.g. valve replacement or repair, coronary artery bypass grafting, etc.).
• 18 years of age or older.
• Written informed consent for study participation obtained before undergoing any study specific procedures.

Intraoperative (at the 1st 5-minute bleeding mass):

• A 5-minute bleeding mass of 60 to 250 g following discontinuation of CPB, administration of protamine, and establishment of surgical hemostasis.
• Minimum core body temperature 35°C, measured according to local practice.
• Activated clotting time ± 25% of baseline levels.
• Blood pH > 7.3.

Exclusion Criteria:

At Screening and/or baseline:

• Undergoing emergency aortic repair surgery.
• Reoperative aortic surgery at the same anatomic site as the original procedure such as replacement of a previously placed aortic graft. Resternotomy and rethoracotomy are permitted.
• Any operation for infection.
• Proof or suspicion of a congenital or acquired coagulation disorder (e.g. Von Willebrand's disease, hemophilia or severe liver disease) or a prothrombotic disorder (e.g. protein C or S deficiency).
• Myocardial infarction (MI), acute coronary syndrome or stroke in the 2 months preceding study surgery.
• Low molecular weight or unfractionated heparin in the 24 hours preceding study surgery.
• Clopidogrel administration within 5 days preceding study surgery or prasugrel administration within 7 days preceding study surgery or ticagrelor administration in the 48 hours preceding study surgery.
• Factor Xa inhibitors within 2 days preceding study surgery.
• IIb/IIIa antagonist administration in the 24 hours preceding study surgery.
• Use of direct thrombin inhibitors: within 3 days preceding study surgery for dabigatran and within 24 hours preceding study surgery for all others.
• An international normalized ratio > 1.3 immediately preceding the start of surgery.

Intraoperative (at the 1st 5-minute bleeding mass):

• Use of any systemic hemostatic therapy (such as FFP, platelets, prothrombin complex concentrates) from the beginning of surgery until IMP administration.