On-pump Beating Coronary Artery Bypass Grafting by Ventricular Assist

Study Overview
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Brief Summary
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The investigators designed the randomized prospective study to evaluate the differences of inflammatory response and clinical outcome after on-pump beating coronary artery bypass grafting undergoing left ventricular assist versus biventricular assist in patients with severe left ventricle dysfunction.

Detailed Description
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Off-pump coronary artery bypass grafting (CABG) tends to have a lower incidence of postoperative complications and remarkable advantages in terms of hospital stay. However, some drawbacks include higher rates of incomplete revascularization and the hemodynamic deterioration during manipulation of the heart, more occurring in the cases of posterolateral anatomical constraints and cardiac dysfunction. It leads to urgent conversion to extracorporeal circulation (ECC) and increases the mortality. Although conventional ECC with cardioplegia arrest provides bloodless immovable field, intense systemic inflammatory response may contribute to hemodynamic unstability especially in patients already with severe cardiac dysfunction. On-pump beating CABG, as a more comprehensive approach, not only facilitates stable hemodynamics and complete revascularization, but also supports myocardial lymphatic flow balance and decreases interstitial myocardial edema in the beating state. Especially in the high-risk patients,some findings suggested that off-pump CABG should be converted to on-pump beating CABG without hesitation, avoiding hemodynamic collapse and even catastrophic outcomes. Some investigators intentionally planned on-pump beating CABG aiming to some patients with severe left ventricle dysfunction. Furthermore, on-pump beating CABG with ECC assistance in a high-risk subgroup is also an acceptable trade-off between conventional cardioplegia and off-pump operations. The above-mentioned ECC results about on-pump, beating-heart CABG pay much attention to the biventricular assist (BiVA). Nonetheless, much evidence also reveals that BiVA triggers an intense inflammatory response due to extracorporeal membrane lung and circuit line. Comparatively speaking, single left ventricular assist (LVA), with shorter circuit line, less priming volume and free of extracorporeal membrane lung, theoretically should reduce the inflammatory response and relative complications. As a result, aiming to the high-risk patients with severe left ventricle dysfunction, who need ECC assistance (BiVA or LVA), the investigators designed the randomized prospective study to evaluate: 1) the differences in myocardial injury as expressed by cardiac Troponin I(cTnI) and in inflammatory response by C-reactive protein (CRP), 2) the differences in the early postoperative outcomes including graft number, incidence of atrial fibrillation, in-hospital mortality and ICU stay.

Official Title
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Inflammatory Response and Clinical Outcome After On-pump Beating Coronary Artery Bypass Grafting Using Left Ventricular Assist Versus Biventricular Assist in Patients With Severe Left Ventricle Dysfunction

Conditions
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Coronary Artery Bypass

Intervention / Treatment
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* Device: left ventricular assist
* Procedure: Biventricular assist


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with severe left ventricle dysfunction with an ejection fraction (EF)≤40%, being scheduled for revascularization. Exclusion Criteria: myocardial infarction within the preceding 4 weeks severe valve disease requiring valve replacement cardiac reoperations

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
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: LVA group<br>LVA group: left ventricular assist group. | Device: left ventricular assist<br>* In left ventricular assist group, 100 IU/kg heparin was given to activated clotting time (ACT) greater than 180 seconds. A 22 French arterial cannula (Maquet, Irrlingen, Germany) was introduced into the ascending aorta, and a 26 French cannula (Eurosets, Medolla, Italy) into the left atrium and advanced into the left ventricle. The two cannulas are directly connected through a short, heparin-coated circuit to a centrifuge pump (Maquet, Getinge Group, Germany). A flow of 1.0 to 4.0 L/min/m2 is obtained and mean blood pressure was maintained 55-75 mm Hg. Note: Both LVA group and BiVA group have the operative protocols itself,includes different prime fluid and cannula pathway. The investigators think it is inapplicable to assign the different operative protocols to the Treatment Arm.<br>|
| Active Comparator: BiVA group<br>BiVA group: Biventricular assist group. | Procedure: Biventricular assist<br>* In biventricular assist group, the patients were routinely heparinized with a dose of 300 IU/kg heparin to ACT greater than 480 seconds. Cardiopulmonary bypass with a centrifuge pump (Maquet, Getinge Group, Germany) was established by 22 French aortic cannulation and 34 French two-stage venous cannula through the right atrial appendage. The extracorporeal circuit was primed with 2000 mL of lactated Ringer's solution, albumin, 25% mannitol and 5% NaHCO3. The flow was 1.0 to 4.0 L/min/m2 and mean blood pressure was maintained 55-75 mm Hg.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of C-reactive protein (CRP) | Serial blood samples for inflammatory response of CRP were collected at the following time points: 1: induction of anesthesia, 2: upon termination of cardiopulmonary bypass (CPB), 3: 6 hours postoperatively, 4: 24 hours postoperatively, 5: 48 hours postoperatively, 6: 72 hours postoperatively. | up tp 72 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of atrial fibrillation | from ICU admission to discharge | 10 days | 
| Durations of mechanical ventilation |  | 10 days | 
| The number for transfused packed red cells | measured by milliliter from ICU admission to discharge | up to 10 days | 
| Partial oxygen pressure/inspired oxygen fraction (P/F) |  | up tp 10 days | 
| Cardiac Troponin I (cTnI) | Serial blood samples for cTnI were collected at the following time points: 1: induction of anesthesia, 2: upon termination of CPB, 3: 6 hours postoperatively, 4: 24 hours postoperatively, 5: 48 hours postoperatively, 6: 72 hours postoperatively. | up to72 hours | 
| In-hospital mortality | from ICU admission to discharge | up to 10 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cardiopulmonary bypass, coronary artery bypass grafting, inflammatory response, cardiac dysfunction