The Transfusion Triggers in Vascular Surgery Trial (TV)
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|ClinicalTrials.gov Identifier: NCT02465125|
Recruitment Status : Completed
First Posted : June 8, 2015
Last Update Posted : July 25, 2017
- Vascular surgical patients often receive red blood cell (RBC) transfusions in the peri-operative period
- RBC transfusion may lead to improved outcome but on the other hand the intervention may be harmful
- Danish Health and Medicines Authority recommends transfusion of RBC at hemoglobin below 5 mmol/L while local clinical guidelines recommend transfusion of RBC to maintain hemoglobin levels above 6 mmol/L
- A large randomized clinical trial is needed to evaluate the efficacy and safety of RBC transfusion in patients undergoing vascular surgery.
- A trial examining the effect of RBC transfusion on tissue oxygenation is used to test the trial-design and feasibility for a trial evaluating post-operative mortality and morbidity.
|Condition or disease||Intervention/treatment||Phase|
|Atherosclerosis Anemia Aortic Aneurysm, Abdominal Arterial Occlusive Diseases||Biological: red blood cell transfusion||Phase 2|
DESIGN Single-center, randomized, open-label trial including vascular surgical patients for peri-operative red blood cell (RBC) transfusion.
If the patient drops out of the trial, either at his/her own request or due to withdrawal from active therapy, the patient will be followed up in the intention-to-treat analyses.
The patient can temporarily be suspended from the protocol in the following circumstances, if the clinician in charge finds indication for blood transfusions not adhering to the planned transfusion threshold:
- Uncontrollable bleeding, defined as loss of surgical hemostasis resulting in overt or imminent hemodynamic instability with insufficient tissue oxygenation and increasing lactate production OR
- Hypotension unresponsive to fluid replacement OR
- Decompensated heart failure OR
- Stroke, extremity- and intestinal ischaemia
SAMPLE SIZE With a total of 50 randomised patients, the trial is powered to
- Show difference in mean postoperative hemoglobin of 1.0 mmol/L. With a power of 95%, 5% significance and a standard deviation of 0.9 mmol/L.
- Show a difference in 2 units (600 mL) of RBC transfused based on a standard deviation of RBC transfusion volume of 717 mL, with a power of 80 % and 5% significance
- Produce a 97.5% confidence interval (CI) equal to the sample adherence prevalence plus or minus 8% when the true prevalence of adherence is hypothesized to be 90%
- Detect a difference in near infrared spectroscopy-determined tissue oxygenation (ScO2) of 6 % during surgery. With a power of 80%, 5% significance and a ScO2-standard deviation of 7%
TIME-LINE The first patient is expected to be randomized June 8th 2015, the last will be randomized March 31st 2016 and the trial database is expected to be closed ultimo June 2016. The main manuscript will be submitted shortly thereafter.
- The Ethical Committee of Region Zealand has approved a protocol amendment of March 29th 2016 for permission of extending the trial period to the end of 2016.
- On September 20th 2016 The Ethical Committee of Region Zealand approved a protocol amendment of September 16th 2016 for permission of extending the sample size to 58 patients and extending the trial period to June 31st 2017.
The 2nd amendment was submitted to compensate for an unexpected high rate of patients randomised postoperatively and thus to secure a sufficient sample size (n=44) for the primary outcome measure, postoperative Hb, and the secondary outcome measures NIRS and ROTEM.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||58 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Supportive Care|
|Official Title:||The Transfusion Triggers in Vascular Surgery Trial: Two Different Transfusion Triggers for Postoperative Haemoglobin Separation and Adherence to Transfusion Strategies in Vascular Surgery: a Randomised Clinical Feasibility Trial|
|Actual Study Start Date :||July 15, 2015|
|Actual Primary Completion Date :||December 8, 2016|
|Actual Study Completion Date :||January 9, 2017|
Active Comparator: Low transfusion trigger
Intervention group. Low or restrictive transfusion trigger: hemoglobin < 5 mmol/L (approx. 8 g/dl or a hematocrit of 25%) This trigger is what is recommended by the Danish Health and Medicines Authority for stable patients with chronic heart disease.
Biological: red blood cell transfusion
Other Name: erythrocyte transfusion
Active Comparator: High transfusion trigger
Control group. High or liberal transfusion trigger: hemoglobin < 6 mmol/L (approx. 10 g/dl or a hematocrit of 30%) This trigger reflects the practice among Danish vascular anesthesiologists and correspond to the transfusion trigger recommended by the European society for vascular surgery
Biological: red blood cell transfusion
Other Name: erythrocyte transfusion
- Mean Post-operative hemoglobin (longitudinal outcome) [ Time Frame: Day 0 - 15 ]Day 0 is the hemoglobin measured upon arrival at the recovery room or at the intensive care unit depending on what level of care the patient needs after surgery.
- Units of red blood cells transfused (count data) [ Time Frame: 30 days after operation ]During 30 day trial period
- Recruitment rate with 95% confidence interval [ Time Frame: Day -1 (day before operation) ]Defined as the ratio of: number of patients included divided by the number of patients eligible (fulfilling the inclusion criteria)
- Protocol suspension [ Time Frame: 30 days after operation ]Number of patients having their protocol suspended after primary inclusion due to hemodynamic instability
- Protocol adherence [ Time Frame: 30 days after operation ]Adherence to hemoglobin concentrations used for transfusion triggers
- Intraoperative tissue oxygenation [ Time Frame: Participants will be monitored during their stay at the operation theatre, an expected average of 3 hours ]The outcome measure is defined as lowest values and area-under-baseline calculations. Baseline is defined as the average saturation value over a 1-min period after the patient has been fluid optimized after induction of anesthesia, before start of surgery.
- Changes in coagulation competence measured by rotational thromboelastometry (ROTEM) [ Time Frame: An expected average time frame of 3 hours ]Changes in coagulation competence will be the baseline ROTEM level (before induction of anesthesia) compared to the end of surgery ROTEM level.
- Severe adverse events [ Time Frame: 30 days after operation ]myocardial injury, acute kidney injury, 30-days mortality, ischemic stroke, severe adverse transfusion reactions
- Explorative Outcomes [ Time Frame: 90 days after operation ]
- Major cardiovascular events (acute myocardial infarction, stroke, renal replacement therapy, vascular reoperation and amputation) (dichotomous outcome) AND
- Days alive outside hospital within 90 days (count data)
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02465125
|Slagelse, Region Zealand, Denmark, 4200|
|Principal Investigator:||Anders Møller, Resident||Slagelse Hospital|