This multi-centre prospective, randomised, double-blind, placebo-controlled study is designed to evaluate the efficacy and safety of bovine intestinal alkaline phosphatase (bIAP) in reducing the pro-inflammatory post-surgical responses and thereby preserving organ functions in patients undergoing invasive cardiac surgery: combined aortic valve replacement and coronary artery bypass grafting.

Inclusion Criteria:

• Male or non-pregnant, non-lactating female patients of any race in the ages of >18 years.
• Patients scheduled for combined aortic valve replacement and CABG surgery.
• Patients who have given written informed consent prior to participation in the trial and who undertake to comply with the protocol.

Exclusion Criteria:

• Patients who are unwilling or unable to be fully evaluated for follow-up.
• Patients who have base AP levels at > 125 IU/L, or levels < 30 IU/L (ammediol, DEA (diethanolamine) units)
• Patients who show pre-operative infections or who are suspected of endocarditis or systemic infection.
• Patients who refuse to accept medically-indicated blood products.
• Patients who have evidence of significant hepatic disease, including history of clinical signs or laboratory values of total bilirubin > 34.2 µmol/L (> 2.0 mg/dL), ALT (>120) or AST (>135) corresponding to > 3X upper limit of normal.
• Patients who received investigational drugs in the 30 days prior to study drug administration, or are currently participating in a study during which the administration of investigational drugs within one month is anticipated.
• Patients who require pre-operative ventilatory support.
• Patients who have renal insufficiency (history of creatinine >177mol/L or >2.0 mg/dL) or chronic renal failure requiring dialysis.
• Patients who are planned to receive leukocyte-depletion filtration as part of the bypass circuitry.
• Patients with severe neurological deficits.
• Patients who have a recent history of drug or alcohol abuse.
• Patients with a diagnosis of idiopathic thrombocytopenia.
• Patients with a history of cancer who have received chemotherapy or radiation therapy within the past 3 months. Patients receiving only adjuvant hormonal therapy are not excluded.
• Patients who are scheduled to receive "stress doses" of glucocorticoids (i.e., doses >2 mg/kg/day of methylprednisolone or equivalent) prior to, during or following surgery.
• Patients who are vegetarians or veganists or those patients that may be expected not to be tolerant for bovine proteins.
• Patients who are, in the opinion of the investigator, unsuitable for the study. A well-documented screening log should be present in the clinic.