The UK CAVIAR Study

The UK CArdiac and Vascular Surgery Interventional Anaemia Response Study: An Observational Cohort Study to Determine the Impact and Effect of Anaemia in Patients Awaiting Vascular and Cardiac Surgery

CAVIAR is a multicentre prospective observational study. Centres for cardiac and vascular surgery assess and manage patients in different ways before surgery. Some centres have introduced the use of intravenous iron therapy for patients with anaemia in the preoperative setting. Consequently regional variation exists in the assessment and management of patients before cardiac and vascular surgery. We aim to observe and measure these differing pathways and observe if there is variation in iron deficiency and anaemia and the impact of these variables on patient cardiorespiratory function as well as post-operative outcomes.

[Sub-Study] For patients who are receiving intravenous iron therapy as part of their routine clinical care, we wish to observe this effect in more detail. We will assess the impact of the treatment on well-being, blood count and fitness. Information will be collected through Quality of Life questionnaires, total haemoglobin mass test (via blood collection) and fitness testing.

Study Overview

• Status: Completed
• Conditions: Iron Deficiency; Anaemia; Cardiac Patients; Vascular Patients
• Intervention / Treatment: Other: Not applicable - observational study

• Study Type: Observational
• Enrollment (Actual): 425

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients requiring major cardiac or vascular surgery will be identified from routine clinical care. Most patients are routinely referred for pre-operative assessment, although local protocols vary between centres. Assesments at the pre-operative assessment clinic (PAC) may include (but not limited to) routine blood tests (full blood count, urea and electrolytes, etc.), history and examination, cardiorespiratory fitness assessment by 6 minute walk test (6MWT) or cardiopulmonary exercise testing (CPET). In some centres, patients with anaemia will receive intravenous iron at PAC or in a separate anaemia clinic.

Description

Inclusion Criteria:

1. Male and female adults aged 18 years or older
2. Screening [Hb] < 120 g/L (for females) or < 130g/L (for males)

3. Undergoing elective cardiac OR vascular surgery:

   • Coronary artery bypass (CABG), or valvular surgery, or combined CABG and valve surgery.
   • Repair or replacement of thoracic or abdominal aorta (open or endovascular).
4. Able to provide informed consent
5. (if applicable) Able to perform CPET or 6MWT if consented to take part in the sub study

Exclusion Criteria:

1. Pregnancy or lactation
2. Adults with known underlying history of learning disabilities, or adults who do not have mental capacity to consent for themselves
3. Prisoners
4. Renal dialysis (current or planned within the next 12 months)

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients undergoing cardiac or vascular surgery	Other: Not applicable - observational study

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in Haemoglobin	From baseline to before surgery (within 10-42 days)

Secondary Outcome Measures

Outcome Measure	Time Frame
Changes in biomarkers of iron deficiency (e.g. hepcidin, ferritin, TfSats)	From baseline to after IV iron (within 4-6 weeks before surgery)
Haemoglobin	Before surgery (within 10-42 days) to post surgery (within 3 weeks)
Unit of blood transfused	Hospital stay (within 7 days)
ICU and hospital length of stay	Within 30 days
Renal function (change in creatinine)	From baseline to before surgery (within 10-42 days)
Renal function (change in creatinine)	From baseline to post surgery (within 3 weeks)
Complications	Within 30 days post surgery
Feasibility - number of successful patient recruitment and consent	Within a year
Total haemoglobin mass test (Sub-study ONLY)	From baseline to after IV iron (within 4-6 weeks before surgery)
Functional exercise testing (CPET or 6MWT) (Sub-study ONLY)	From baseline to after IV iron (within 4-6 weeks before surgery)
Quality of Life (Sub-Study ONLY)	From baseline to i) after IV iron (within 4-6 weeks before surgery), ii) post surgery (within 3 weeks)

Collaborators and Investigators

• Sponsor: University College, London
• Investigators: Principal Investigator: Toby Richards, MD FRCS, University College, London

Publications and helpful links

General Publications

• Chau M, Richards T, Evans C, Butcher A, Collier T, Klein A. The UK Cardiac and Vascular Surgery Interventional Anaemia Response (CAVIAR) Study: protocol for an observational cohort study to determine the impact and effect of preoperative anaemia management in cardiac and vascular surgical patients. BMJ Open. 2017 Apr 18;7(4):e014872. doi: 10.1136/bmjopen-2016-014872.

Helpful Links

• Related Info
• Related Info

Study record dates

Study Major Dates

• Study Start: November 1, 2015
• Primary Completion (Actual): March 1, 2018
• Study Completion (Actual): April 1, 2019

Study Registration Dates

• First Submitted: November 27, 2015
• First Submitted That Met QC Criteria: December 21, 2015
• First Posted (Estimate): December 22, 2015

Study Record Updates

• Last Update Posted (Actual): May 16, 2023
• Last Update Submitted That Met QC Criteria: May 12, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Hematologic Diseases; Anemia
• Other Study ID Numbers: 15/0659

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No