Here is the design of a clinical trial:

Official Title: Efficacy of a Glucagon-like-peptide-1 Agonist and Restrictive vs. Liberal Oxygen Supply in Patients Undergoing Coronary Artery Bypass Grafting or Aortic Valve Replacement - a 2-by-2 Factorial Designed, Randomized Clinical Study

Included conditions:
- Coronary Disease
- Shock, Cardiogenic
- Renal Failure
- Stroke
- Brain Injury
- Aortic Valve Disease

Study Armgroups:
- {'label': 'GLP-1', 'type': 'EXPERIMENTAL', 'description': '700 patients will be randomized to GLP-1, that will be administered as follows:\n\n248.5 mL of isotonic sodium chloride added 1.5 mL of 20% human albumin added 25 microg Byetta (Lilly, Exenatide).\n\nThe study drug infusion is initiated immediately before open heart surgery and ended after 6 hours and 15 minutes. A set dose of 17.4 microg will be given.', 'interventionNames': ['Drug: Byetta (Lilly, Exenatide)']}
- {'label': 'Placebo', 'type': 'PLACEBO_COMPARATOR', 'description': '20% Human Albumin is given as placebo. 700 patients will be randomized to placebo, that will be administered as follows:\n\n248.5 mL of isotonic sodium chloride added 1.5 mL of 20% human albumin.\n\nThe placebo infusion is initiated immediately before open heart surgery and ended after 6 hours and 15 minutes at the same rate as the study drug.', 'interventionNames': ['Drug: 20% Human Albumin']}
- {'label': 'Restrictive Oxygenation', 'type': 'EXPERIMENTAL', 'description': "The intervention is FiO2 of 50%, given as 'Conoxia (AGA, oxygen)'. 700 patients will be randomized to a FiO2 of 50% as long as the arterial O2 saturation (Sa02) remains above 91% during cardiopulmonary bypass, when weaning from and the following hour after weaning from cardiopulmonary bypass. The oxygenation strategy is discontinued and the patient is treated at the discretion of the attending physician after\n\n1. a maximum of 1 hours of intervention or\n2. the patient is slid from the operating table to a hospital bed for transfer to the intensive care unit, whichever comes first.", 'interventionNames': ['Drug: Conoxia (AGA, oxygen)']}
- {'label': 'Liberal Oxygenation', 'type': 'ACTIVE_COMPARATOR', 'description': "The intervention is a FiO2 of 100%, given as 'Conoxia (AGA, oxygen)'. 700 patients will be randomized to a FiO2 of 100% during cardiopulmonary bypass, when weaning from and the following hour after weaning from cardiopulmonary bypass. The oxygenation strategy is discontinued and the patient is treated at the discretion of the attending physician after\n\n1. a maximum of 1 hours of intervention or\n2. the patient is slid from the operating table to a hospital bed for transfer to the intensive care unit, whichever comes first.", 'interventionNames': ['Drug: Conoxia (AGA, oxygen)']}

Interventions:
- {'type': 'DRUG', 'name': 'Byetta (Lilly, Exenatide)', 'description': 'See description of arms', 'armGroupLabels': ['GLP-1'], 'otherNames': ['GLP-1 agonist']}
- {'type': 'DRUG', 'name': 'Conoxia (AGA, oxygen)', 'description': 'See description arms', 'armGroupLabels': ['Liberal Oxygenation', 'Restrictive Oxygenation'], 'otherNames': ['Oxygen']}
- {'type': 'DRUG', 'name': '20% Human Albumin', 'armGroupLabels': ['Placebo'], 'otherNames': ['Albumin']}

Primary Outcomes:
- {'measure': 'Time in days to the first occurring of the following co-primary end-points throughout the follow-up period', 'description': '1. Death from any cause or\n2. Any of the following adverse events\n\n   1. Renal failure requiring any type of renal replacement therapy\n   2. Stroke, defined as persisting (\\>24 hours) of any neurological sign or symptom of neurological dysfunction as determined by the treating physician based on available clinical information or CT-scan\n   3. New onset/worsening heart failure defined as need for mechanical circulatory support at the ICU, inability to close the sternotomy due to post-surgical hemodynamic instability and/or persistent (\\> 48 hours from initiation of first surgical procedure after randomization) need for inotropic hemodynamic support. In addition admission for heart failure during follow-up following discharge from the index admission.', 'timeFrame': 'Minimum 12 months'}

Please estimate the sample size based on the assumption: 
The power is set at 80% with a significance level (Î±) of 0.05 (two-sided).
Sample size estimation
          This parallel group trial investigates two interventions, and we plan to analyse these two interventions as two separate studies. The effect of the two interventions are not expected to interact, therefore, the design and sample size estimation did not account for such interaction. The study involving restrictive versus liberal oxygenation is subordinate to the study involving the GLP-1 analogue, and the potential interactions of the two interventions will be analysed in the GLP-1 analogue trial. Thus, the power calculations are based on the GLP-1 analogue intervention.
          The trial is event driven, aiming at 323 primary endpoints to be able to show a 25% reduction in the primary endpoint with a power of 80% at an Î±-level of 0.05 (two sided). Based on cumulative event rates from the surgical register at Rigshospitalet (unpublished), a total of 1400 patients are needed to reach a total of 323 events during follow-up. We will include 1400 patients in the trial. We will follow all patients until 323 events have been reached and the last patient has been followed for a minimum of 12 months. Accordingly, the follow-up period will vary from approximately 6 years from the earliest included patients to 12 months for the last included patient.