Optimal Cardiopulmonary Bypass and Anticoagulation Management Strategies in Obese Patients Undergoing Cardiac Surgery

Study Overview
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Brief Summary
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Standard Heparin management, based on total body weight, is not well established for obese patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). The purpose of this study is to assess the safety and efficacy of using lean body mass (LBM) to determine pump flow rate and/or Heparin dosage in obese patients undergoing CPB.

Official Title
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Optimal Cardiopulmonary Bypass and Anticoagulation Management Strategies in Obese Patients Undergoing Cardiac Surgery

Conditions
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Cardiopulmonary Bypass, Obesity

Intervention / Treatment
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* Drug: Heparin
* Procedure: cardiopulmonary bypass pump flow rate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Obese patients (BMI ≥ 30kg/m2) Planned cardiac surgery Age ≥ 18 years Exclusion Criteria: Permanent pacemaker Known intolerance to protamine Known or suspected allergy to the used antifibrinolytic agent Refusal to receive blood products Planned off pump coronary artery bypass Planned peri-operative use of desmopressin Known Heparin-induced thrombocytopenia Known deficiency in protein C, protein S, antithrombin or homozygous factor V Leiden Known congenital bleeding disorders Current endocarditis Planned hypothermic circulatory arrest (<28C) Two or more cardiac surgery procedures Emergency cardiac surgery procedures (medically required within 24hours of presenting with acute symptoms) Planned CPB priming with red blood cells Any known autoimmune disease Any history of stroke or non-coronary thrombotic disorders including deep venous thrombosis and pulmonary embolism Significant (≥50%) carotid artery stenosis Patient dosed with low molecular weight Heparin less than 24h before surgery Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using adequate contraceptive methods Confirmed ST elevation myocardial infarction (STEMI) within 7 days Pre-operative platelet count <100,000/microliter Anaemia (Hematocrit <32% for females, <35%for males) Dosed with clopidogrel or ticagrelor within the last 5 days prior to surgery, or prasugrel within 7 days Dosed with GPIIb/IIIa receptor blockers (Abciximab, Tirofiban, Eptifibatide) ≤ 24 hours prior to surgery International ratio (INR) >1.5 on the day of surgery in patients treated with vitamin K antagonist Liver dysfunction (aspartate aminotransferase (AST) or alanine aminotransferase (ALT) increased ≥ 2-fold above the upper limit of local laboratory normal ranges) Renal failure (creatinine ≥ 175 micromol/L or dialysis) Current thromboembolic disease other than myocardial infarct Patients who have pre-donated autologous blood Patient presenting with a resistance to Heparin

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized control prospective trial
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control group<br>Heparin dose and cardiopulmonary bypass pump flow rate are calculated using total body weight. An initial 400 IU/Kg Heparin dose will be administered, with an additional dose of 75 IU/kg if the activated clotting time remains below the 425 seconds target value. The cardiopulmonary bypass pump flow rate of 2.4 L/min/m2 of body surface area will be calculated. | Drug: Heparin<br>* Based on patient body weight (UI/kg)<br>Procedure: cardiopulmonary bypass pump flow rate<br>* Based on patient body weight (L/min/m2)<br>|
| Experimental: Intervention group A<br>Heparin dose is adjusted for lean body weight and cardiopulmonary bypass pump flow rate is calculated using total body weight. An initial 400 IU/Kg Heparin dose will be administered, with an additional dose of 75 IU/kg if the activated clotting time remains below the 425 seconds target value. The cardiopulmonary bypass pump flow rate of 2.4 L/min/m2 of body surface area will be calculated. | Drug: Heparin<br>* Based on patient body weight (UI/kg)<br>Procedure: cardiopulmonary bypass pump flow rate<br>* Based on patient body weight (L/min/m2)<br>|
| Experimental: Intervention group B<br>Heparin dose is calculated using total body weight and cardiopulmonary bypass pump flow rate is adjusted for lean body weight. An initial 400 IU/Kg Heparin dose will be administered, with an additional dose of 75 IU/kg if the activated clotting time remains below the 425 seconds target value. The cardiopulmonary bypass pump flow rate of 2.4 L/min/m2 of body surface area will be calculated. | Drug: Heparin<br>* Based on patient body weight (UI/kg)<br>Procedure: cardiopulmonary bypass pump flow rate<br>* Based on patient body weight (L/min/m2)<br>|
| Experimental: Intervention group C<br>Heparin dose and cardiopulmonary bypass pump flow rate are adjusted for lean body weight. An initial 400 IU/Kg Heparin dose will be administered, with an additional dose of 75 IU/kg if the activated clotting time remains below the 425 seconds target value. The cardiopulmonary bypass pump flow rate of 2.4 L/min/m2 of body surface area will be calculated. | Drug: Heparin<br>* Based on patient body weight (UI/kg)<br>Procedure: cardiopulmonary bypass pump flow rate<br>* Based on patient body weight (L/min/m2)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Allogeneic transfusions of red blood cells | Percentage of subjects avoiding any allogeneic transfusions of red blood cells | Seven days post-operatively or until discharge, whichever comes first | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Allogeneic transfusions of blood products | Percentage of subjects avoiding any allogeneic transfusions | Seven days post-operatively or until discharge, whichever comes first | 
| Units of blood product transfusions | Number of units of transfused blood products | Seven days post-operatively or until discharge, whichever comes first | 
| Massive red blood cell transfusions | Percentage of subjects avoiding massive red blood cell transfusion (more than 5 units) | Seven days post-operatively or until discharge, whichever comes first | 
| Post-operative complications | Monitoring the safety of strategies by monitoring post-operative complications | Post-operatively from day 0 up to first hospital discharge | 
| Bleeding | Per- and post-operative bleeding | Peroperative, 4 and 24 hours post-operative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heparin, Allogeneic blood product transfusions, Bleeding, Cardiac surgery, Obesity