Thrombin Generation During Cardiopulmonary Bypass With Titrated Versus Conventional Anticoagulation Management.
- Conditions
- Cardiac Surgery
- Interventions
- Device: HMS Plus
- Registration Number
- NCT03347201
- Lead Sponsor
- University Health Network, Toronto
- Brief Summary
In this study, the investigators will be comparing anticoagulation for Cardiopulmonary Bypass (CPB) guided by the Hemostasis Management System (HMS Plus) with the current dosing based on weight and ACT measurements.
The primary objective of this study is to determine whether relative to patients with conventional management, those managed with the HMS Plus have improved thrombin generation after CPB.
The secondary objective is to determine if patients in the HMS Plus group have reduced blood loss in the first 24 hours following surgery compared with patients in the conventional group.
- Detailed Description
Cardiopulmonary bypass (CPB) allows cardiac surgery to be performed on a motionless, bloodless heart while maintaining circulation to the rest of the body. Anticoagulation with heparin prevents the body's clotting system from being activated when blood comes into contact with the walls of the bypass circuit. The amount of heparin given to achieve this effect is determined on a weight-based dosing and monitored with a point-of-care monitor called ACT (activated clotting time). However, there remains a high level of variability in the concentration of heparin in the blood and the ACT is affected by hypothermia and dilution of the blood, both of which commonly occur during CPB for cardiac surgery.
The Hemostasis Management System (HMS Plus) offers an alternative way of dosing and monitoring heparin by aiming to achieve a pre-determined heparin concentration throughout CPB, rather than being determined by the ACT. It also aims to determine the dose of protamine, the drug used to reverse heparin at the end CPB, required based on residual heparin concentration rather than on a 1:1 ratio of the total dose of heparin given which is the common current practice. The benefits of using this system are proposed to be more effective anticoagulation during CPB meaning less of the body's reserves of clotting factors are consumed. This could mean potentially less bleeding and decrease requirement of blood products following surgery.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 100
- Scheduled to undergo non-emergent coronary artery bypass grafting, valve repair or replacement (with or without ascending aortic replacement) or a combination of these procedures requiring the use of CPB
- Less than 18 years old
- Planned use of deep hypothermic circulatory arrest
- Cases where use of brief circulatory arrest anticipated
- Highly complex cases (LVAD, Heart Transplant, Complex congenital)
- Significant liver dysfunction (liver enzymes > 2-fold higher than upper limit of normal
- Pre-existing coagulopathy (INR >1.5, PTT >45 seconds, fibrinogen < 1.0g/L, platelet count <100x109/L)
- Use of long acting oral anticoagulants
- Patients on heparin infusions pre-operatively
- Major hemoglobinopathies, thalassemia or iron storage diseases
- Previous diagnosis of HIT
- Lack of informed consent
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Intervention Group HMS Plus 1. Initial heparin bolus before CPB to be calculated using HMS Plus. 2. Following commencement of CPB further heparin requirements will be determined using the HMS Plus. ACT's will also be checked whilst on CPB and if falls below 480 seconds, additional heparin will also be given. 3. Following cessation of CPB the dose of protamine required to reverse residual heparin will be calculated using the HMS Plus.
- Primary Outcome Measures
Name Time Method Thrombin Generation Intra-operative The primary outcomes will be thrombin generation potential assessed via peak thrombin and endogenous thrombin potential on CAT thrombograms of plasma samples taken before, during and after cardiopulmonary bypass.
- Secondary Outcome Measures
Name Time Method Platelet Function Analysis (PFA) Intra-operative PFA will be performed
Blood loss Intraoperative day to the 7th postoperative day inclusive Amount of blood loss
Activated Clotting Time (ACT) Intra-operative ACTs are performed during surgery
Blood product transfusion Intraoperative day to the 7th postoperative day inclusive Collection of blood products transfused
Rotational thromboelastometry (ROTEM) Intra-operative Rotational thromboelastometry will be performed on the ROTEM delta instrument using citrated whole blood.
Trial Locations
- Locations (1)
Toronto General Hospital, University Health Network
🇨🇦Toronto, Ontario, Canada