Effects of Remote Ischemic PreConditioning in Off-pump Versus On-pump Coronary Artery Bypass Grafting(RIPCON)

Effects of Remote Ischemic PreConditioning in Off-pump Versus On-pump Coronary

Purpose Remote ischemic preconditioning (RIPC) with transient upper limb ischemia reduces myocardial injury in patients undergoing On-pump coronary artery bypass (CABG) surgery with cross-clamp fibrillation or blood cardioplegia for myocardial protection. The molecular mechanisms leading to these effects are yet not fully understood. The purpose of the present study is to validate previous studies and gather further evidence for RIPC during CABG with blood cardioplegia, furthermore to determine, whether or not RIPC is still operative during Off-pump coronary artery bypass surgery (OPCAB), finally to elucidate intra-cellular mechanisms involved in myocardial protection by RIPC and their possible systemic mediators.

Remote ischemic preconditioning (RIPC) protocol before CABG (study arm A) or OPCAB (study arm B) consists of 3 cycles of 5 minutes left upper arm ischemia by inflation of a blood pressure cuff to 200 mmHg and 5 minutes of reperfusion after induction of anesthesia before coronary artery bypass surgery. For myocardial molecular analyses, left ventricular biopsies are taken before induction of cardioplegic cardiac arrest (A) or first coronary incision (B), and 5 to 10 minutes after aortic unclamping during reperfusion of the myocardium (A) or 5 to 10 minutes after the completion of the last anastomosis (B). Blood samples are taken prior to RIPC and during the first three postoperative days.

Inclusion Criteria:

• Confirmed triple vessel coronary artery disease
• Indication for surgical coronary revascularisation
• Written informed consent
• Age ≥ 18 years

Exclusion Criteria:

• Age > 80 years
• Instable angina/acute coronary syndrome
• Emergency surgery
• Recent myocardial infarction within 7 days prior to surgery
• Recent major infection/sepsis within 7 days prior to surgery
• Significant hepatic, renal oder pulmonary disease
• Other concomitant surgical procedures