Here is the design of a clinical trial:

Official Title: Prevention of Vasoplegia With the Use of CytoSorb.

Included conditions:
- Heart Failure
- Vasoplegia

Study Armgroups:
- {'label': 'CytoSorb-Yes', 'type': 'ACTIVE_COMPARATOR', 'description': 'Heart failure patients that will receive intraoperative treatment with CytoSorb.', 'interventionNames': ['Device: CytoSorb device']}
- {'label': 'CytoSorb-No', 'type': 'NO_INTERVENTION', 'description': 'Heart failure patients that will not receive intraoperative treatment with CytoSorb.'}

Interventions:
- {'type': 'DEVICE', 'name': 'CytoSorb device', 'description': 'The CytoSorb device will be placed in the CPB circuit in half of the study population during their cardiac operation.', 'armGroupLabels': ['CytoSorb-Yes']}

Primary Outcomes:
- {'measure': 'Delta systemic vascular resistance index (SVRi) after CPB.', 'description': 'The change in SVRi after the administration of phenylephrine after cessation of CPB.', 'timeFrame': 'during surgery (2-10 hours)'}
- {'measure': 'Incidence of vasoplegia.', 'description': 'Vasoplegic syndrome defined as the continuous need of vasopressors (norepinephrine ≥0.2 μg/kg/min for at least 12 consecutive hours, terlipressin, or methylene blue) in combination with a cardiac index (CI) ≥2.2 l/min/m2 for at least 12 consecutive hours, starting within the first 3 days postoperatively.', 'timeFrame': '72 hours'}

Please estimate the sample size based on the assumption: 
90% power, 0.05 two-sided significance level, and compensation for possible data loss
Sample size calculation
        The primary endpoint is delta SVRi with phenylephrine challenge after CPB. A sample size of 17 patients in each treatment group will have 90% power to detect a difference in means of 400âdyn s/cm5 assuming that the common SD is 350âdyn s/cm523 and when using a 0.05 two-sided significance level. To compensate for possible loss of data due to failing of the vasoconstriction test, one extra patient will be included in each group, resulting in a total sample size of 36 patients.