Study on CRP Apheresis After Coronary Bypass Surgery

CABY1 is a clinical trial to study the reduction of C-reactive protein (CRP) by therapeutic apheresis (CRP apheresis) in patients undergoing elective primary coronary bypass surgery.

The term therapeutic apheresis describes therapeutical procedures whose effect is based on the elimination of blood components with a pathogenic function within the disease process. Elimination takes place in adsorbers outside the body in an extracorporeal circuit. To remove the pathogenic substances, blood plasma is separated from the circuit and passed through an adsorber. The purified blood plasma is then reunited with the solid blood components and returned to the patient.

The "PentraSorb® CRP" adsorber used for CRP apheresis is CE-certified. It serves for the selective depletion of the C-reactive protein from human plasma.

As a cause of the damaging effect of the C-reactive protein it is assumed that the CRP as an inflammatory mediator favours the destruction of cardiac muscle tissue (in conjunction with complement) and has a negative influence on the regeneration of the traumatized tissue.

The aim of the CABY1 study is to investigate if the tissue damage of the heart can be reduced by depletion of the C-reactive protein after elective coronary bypass surgery. A possible protective effect of CRP apheresis will be determined from laboratory biomarkers (e.g., troponin I, CM-MB, IL-6) and cardiac events.

20 randomly selected patients receive apheresis treatments with a duration of 4-6 h each the following 2-3 days after bypass surgery, the 20 patients of the controls do not receive apheresis. The biomarkers required for the evaluation of the treatment success are determined over a period of 4 days after surgery on the basis of the routine blood tests. Cardiac events are documented until the patient is discharged.

Inclusion criteria

• elective, isolated, primary coronary bypass surgery
• 2 or 3-fold CHD with or without main stem stenosis
• Obtained LVEF (> 30%, trans-oesophageal echocardiography (TEE) or angiography)
• Heart-lung machine (HLM; 'two-stage' cannulation)
• Antegrade Bretschneider cardioplegia
• Mild hypothermia (32 °C)
• Standard anesthesia (isoflurane)
• Intraoperative standard protocol (500 mg ASA after 2 h, low dose heparinization after 4 h)
• written informed consent
• legal capacity

Exclusion criteria

Preoperatively

• PCI (within last 2 weeks)
• Renal insufficiency (creatinine > 1.3 mmol/L or requiring dialysis)
• Combination interventions
• Re-surgery
• Emergency of urgent surgery indication
• Acute coronary syndrome (IAP, NSTEMI, STEMI)
• Preoperatively positive hs-troponin I > 40 ng/ml
• Chronic arterial fibrillation
• Acute infectious disease (body temperature > 38.0°C)
• Systolic blood pressure < 100 mmHg
• Known hypersensitivity to therapeutic apheresis
• Cardiac shock
• Pregnancy or lactation
• Participation in other interventional trial

During surgery

• Radialis removal
• Coronary TEA (if blood flow within bypass < 20 ml/min)
• Off-pump
• Hemofiltration
• Combination intervention (e.g. mitral valve reconstruction, LAA)
• Maze procedure
• Bypass low-flow closure, ECG changes
• Antithrombotic therapy (intraoperative clopidogrel and/or aspirin)
• Second HLM
• Second cardioplegic cardiac arrest
• Intraaortal balloon pumping / balloon pulsation (IABP)
• Extracorporeal membrane oxygenation (ECMO)