Remote ischemic preconditioning (RIPC) with transient upper limb ischemia/reperfusion provides peri-operative myocardial protection, is safe and improves prognosis in patients undergoing elective CABG surgery. The signal transfer from limb to heart is unknown. Thus, the aim of this study is to identify the pathways which transfer the cardioprotective signal from the ischemic/reperfused extremity to the heart in humans undergoing surgical coronary revascularization.
The investigators will obtain arterial blood samples before skin incision and 1-72 h after the remote ischemic preconditioning protocol and analyze them biochemically. The investigators focus on those ligands that have been previously implicated in conditioning protocols at any organ. In addition, the investigators will use a bioassay system, consisting of a Langendorff-perfused isolated heart with coronary occlusion/reperfusion and infarct size by TTC staining as endpoint, and then expose this bioassay system to arterial plasma obtained after the remote ischemic preconditioning stimulus or placebo. This approach will allow us to further characterize any potential transfer signal candidate with a pharmacological antagonist approach. The investigators will also obtain human atrial appendages after the remote ischemic preconditioning protocol or placebo and before patients were connected to the extracorporeal circulation. Contractile function of isolated trabeculae and vasomotor function of isolated arterial vessels will be analyzed in a bioassay system.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
TRIPLE
Enrollment
392
3 cycles of 5 min left upper arm ischemia by inflation of a blood pressure cuff to 200 mmHg and 5 min reperfusion
Herzzentrum Essen - Huttrop gGmbH, Einrichtung des Universitätsklinikums Essen
Essen, Germany
Myocardial protection
Cumulative postoperative troponin T release
Time frame: 72 h, postoperatively
All-cause mortality
follow up done by studynurses
Time frame: 30 days and 1 year after CABG surgery and after complete follow-up
MACCE
Major adverse cardiac and cerebrovascular events
Time frame: 30 days and 1 year after CABG surgery after complete follow-up
renal function
Creatinine and eGFR
Time frame: 72 h, postoperatively
Cardioprotective factors released into circulating blood
Analysis of blood plasma
Time frame: before skin incision versus 1-72 h after RIPC
Myocardial function in vitro
left ventricular pressure (lvp) and maximum left ventricular pressure (lvdp) in an isolated perfused rodent heart after blood plasma infusion
Time frame: after RIPC
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