None listed
Conditions
Brief summary
One of the major constituents of mammalian blood is haemoglobin. Haemoglobin is a protein complex bound to red blood cells, and is responsible for the delivery of oxygen to, and removal of carbon dioxide from the tissues. A shortage of haemoglobin is called ‘anaemia’. If a patient has anaemia before or after major surgery, they are more likely to develop a complication after their operation, and more likely to die. The worse the anaemia, the worse the risk. The prevention and treatment of anaemia is therefore of great importance to patients and their clinicians alike, especially patients who have required cardiac surgery, as the incidence of postoperative anaemia in these individuals is very high. However, anaemia is a symptom of a broader problem, not a diagnosis in and of itself. It has many, many potential causes, and while we suspect that anaemia after cardiac surgery is driven by a combination of blood loss and inflammation, this is yet to be proven. In general, the treatments that are available for anaemia that was present after an operation are effectively limited to blood transfusion. However, blood transfusion itself is associated with an increased risk of poor outcome. Because of the lack of treatment options, specialists have been generally incurious about what drives anaemia following an operation. However, over the last ten years, our understanding of the drivers of anaemia in general has improved markedly, which in turn has resulted in the development of several new therapies. Clinicians, therefore, have options that could be useful to treat anaemia after major surgery, including cardiac surgery. However, to apply these new treatments effectively, we must first understand what causes anaemia after cardiac surgery, and for how long this process lasts. The MOSAICS study has been designed with this conundrum in mind and will explore and define the many possible causes of anaemia after cardiac surgery. Volunteers having cardiac surgery at two hospitals will have their blood tested several times following their operation (both in hospital and for the first nine weeks after the operation) to examine the resolution of inflammation postoperatively, and to determine how this influences changes in the body’s handling of iron (a key component of haemoglobin), and the body’s ability to generate new haemoglobin to replace that which was lost during the operation. By determining the underlying cause of anaemia, we can design new studies that will target this cause. If successful, MOSAICS will provide important insights into the causes of postoperative anaemia and identify the best targets for novel treatments for this major problem, that continues to affect outcomes and quality of life for patients who are undergoing cardiac surgery.
Interventions
The majority of data will be collected from the medical record without the need for patient involvement. Patients will be required to undergo a blood test prior to commencement of surgery, and on postoperative days 1, 2, 4, 8, 16, 32 and 64. The first three of these will be performed as an inpatient. The last three will require the patient to return to hospital to have them performed. This will be timed with routine cardiac rehabilitation after surgery. The patient will also undergo a 6 minute w
The majority of data will be collected from the medical record without the need for patient involvement. Patients will be required to undergo a blood test prior to commencement of surgery, and on postoperative days 1, 2, 4, 8, 16, 32 and 64. The first three of these will be performed as an inpatient. The last three will require the patient to return to hospital to have them performed. This will be timed with routine cardiac rehabilitation after surgery. The patient will also undergo a 6 minute walk test on or about days 32 and 64. This again will be incorporated into rehabilitation.
Sponsors
Department of Critical Care, The University of Melbourne
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
All patients undergoing coronary artery bypass or cardiac valve surgery
Exclusion criteria
Undergoing cardiac surgery that is not CABG and/or cardiac valve procedures (i.e., ascending aorta or root replacement, solid organ transplantation, etc.) End-stage renal failure requiring dialysis Active solid organ malignancy Taking antibiotic therapy for active infection at time of operation Acquired/clonal haematological malignancies (including leukaemia, lymphoma, myeloma, myelodysplasia, or aplastic anaemia) Haemoglobinopathy (including a-globin and/or ß-globin gene mutations [thalassaemia] and sickle cell trait) Inherited red cell membrane disorders (including glucose-6-phosphate-dehydrogenase and pyruvate kinase deficiency) Active haemolytic processes (mechanical or autoimmune) Preoperative requirement for erythropoiesis stimulating agents Age < 18 years Pregnancy or breastfeeding Surgical plan requiring off-pump technique Preoperative Hb < 130 g/L if male and < 120 g/L if female Preoperative C-reactive protein (CRP) concentration > 5 mg/L Emergency surgery (i.e., following decision to operate, the patient proceeds to surgery before the next business day) Not willing to attend for blood tests following discharge.
Outcome results
None listed