Remote ischemic preconditioning in on-pump coronary artery bypass graft surgery

In this placebo-controlled randomized controlled trial, we tested whether remote ischemic preconditioning (RIPC) elicited by four 5-minute cycles of 300 mmHg of cuff inflation/deflation of the lower limb would reduce myocardial necrosis in isoflurane-anesthetized patients undergoing on-pump coronary artery bypass graft surgery. Secondary outcomes were the perioperative release of the biomarkers NTproBNP, hsCRP, S100, atrial transcriptional profiles, and short- and long-term clinical outcomes. RIPC with concomitantly applied isoflurane did not affect the release of biomarkers or clinical outcome. NTproBNP release correlated with isoflurane- but not RIPC-induced transcriptional changes. For eleven randomly selected patients from each group (RIPC/CTL=no RIPC) two atrial samples were collected, one at the time of cannulation (T1) and one fifteen min after releasing the cross clamp (T2). The samples were immediately frozen in liquid nitrogen and later used for RNA isolation and subsequent microarray hybridization. Gene-level analysis was performed. the results of exon-level analysis will be published separately (only preliminary results available so far).