Neurocognitive Outcome After Coronary Artery Bypass Surgery Using Minimal Versus Conventional Extracorporeal Circulation

Study Overview
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Brief Summary
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The aim of this study is to assess the effect of minimal (MECC) versus conventional (CECC) extracorporeal circulation on neurocognitive function after elective coronary bypass grafting (CABG) as well as whether this can be attributed to improved cerebral perfusion intraoperatively.

Detailed Description
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Despite improvements in the biocompatibility of cardiopulmonary bypass (CPB) circuits, the activation of inflammatory systemic response can result in clinically relevant organ dysfunction. Regarding the central nervous system, prolonged hypoperfusion and microembolization during conventional CPB have been related to postoperative neurologic impairment with an incidence varying from 30% to 60%. This clinical scenario covers a spectrum from a transient subtle cognitive dysfunction to a permanent stroke. Postoperative cognitive decline (POCD) is characterized as impairment in attention, cognition, recognition, orientation, memory, and learning. It may result in prolonged hospitalization, increased morbidity and mortality, while it has an adverse impact on quality of life after surgery. Near-infrared spectroscopy (NIRS) provides a continuous and noninvasive monitoring of regional cerebral oxygen saturation (rSO2). Recent studies have shown a significant relationship between intraoperative cerebral oxygen desaturation, indicative of cerebral ischemia, and early POCD in patients undergoing elective coronary bypass grafting (CABG) with conventional extracorporeal circulation (CECC). In an attempt to reduce CPB-inherent side effects, a minimal extracorporeal circulation (MECC) system was developed and it is evaluated in clinical practice. The aim of this pilot study was to define whether there is a difference in early postoperative neurocognitive functioning between patients being operated for CABG on MECC versus CECC systems as well as whether this can be attributed to improved cerebral perfusion intraoperatively.

Official Title
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Neurocognitive Outcome After Coronary Artery Bypass Surgery Using Minimal Versus Conventional Extracorporeal Circulation

Conditions
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Coronary Artery Bypass

Intervention / Treatment
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* Procedure: Coronary artery bypass grafting with the use of minimal extracorporeal circulation
* Procedure: Coronary artery bypass grafting under conventional extracorporeal circulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients scheduled for elective coronary artery bypass grafting Exclusion Criteria: history of psychiatric disorder inability to undergo neuropsychological assessment history of transient ischemic attack or stroke carotid artery stenosis > 60% assessed by duplex ultrasonography
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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: MECC Group<br>Patients operated for elective coronary artery bypass grafting with the use of minimal extracorporeal circulation. | Procedure: Coronary artery bypass grafting with the use of minimal extracorporeal circulation<br>* The MECC system (Maquet Cardiopulmonary, Hirlingen, Germany) consists of a pre-connected closed CPB circuit containing a RotaFlow centrifugal pump and a Quadrox D diffusion membrane oxygenator. A flow meter and a bubble sensor are integrated in the drive unit of the centrifugal pump. The system features a tip-to-tip heparin coating (Bioline Coating, Maquet Cardiopulmonary, Hirlingen, Germany). No arterial or venous line filters are included. Initial priming volume of the system is 500 mL, while using retrograde autologous priming (RAP) the circuit could be filled in with autologous blood, thus reducing hemodilution. Since no cardiotomy suction is used, shed blood is collected with a cell-saving device (Haemonetics Corp, Braintree, MA).<br>|
| Active Comparator: CECC Group<br>Group of patients undergoing elective coronary bypass grafting with the use of conventional extracorporeal circulation. | Procedure: Coronary artery bypass grafting under conventional extracorporeal circulation<br>* A standard open CPB circuit is used, consisting of uncoated PVC tubing, a hard-shell venous reservoir, a microporous membrane oxygenator (Dideco, Mirandola, Italy) and a roller pump (Stöckert S3, Munich, Germany). The circuit contains a 40 μm arterial line blood filter (Dideco, Mirandola, Italy) and it is primed with 1500 mL of a balanced crystalloid/colloid solution (1000 mL of Ringer's solution, 200 mL of mannitol 20%, and 300 mL of hydroxyethyl starch 6%). Cardiotomy as well as sump sucker are integrated to the circuit.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neurocognitive outcome at 3-month follow-up | Neurocognitive outcome at 3-month follow-up after elective coronary artery bypass grafting with the use of minimal (MECC) versus conventional (CECC) extracorporeal circulation. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neurocognitive outcome at discharge | Neurocognitive score assessed at the time of discharge after elective coronary surgery with the use of minimal (MECC) versus conventional (CECC) extracorporeal circulation. | 7-30 days | 
| Episodes of intraoperative cerebral desaturation | Number of episodes and duration of cerebral desaturation assessed with the use of near-infrared spectroscopy after elective coronary artery bypass grafting with minimal (MECC) versus conventional (CECC) extracorporeal circulation. | During the operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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coronary artery disease; coronary artery bypass grafting; cardiopulmonary bypass; minimal extracorporeal circulation