Abstract 4707: Remote Ischemic Preconditioning Reduces Myocardial Injury After Coronary Artery Bypass Surgery With Cristalloid Cardioplegic Arrest
Background: Remote ischemic preconditioning (RIPC) by transient upper limb ischemia decreases myocardial injury in patients undergoing coronary artery bypass (CABG) surgery when using cross-clamp fibrillation for myocardial protection. Whether or not such protection is still present when cardioplegic arrest is used for myocardial protection is uncertain.
Methods and Results: Forty-seven consecutive, non-diabetic patients with triple-vessel coronary artery disease (age: 64 years±12, mean±SD) undergoing elective CABG surgery with crystalloid (Bretschneider) cardioplegic arrest were analyzed. In a prospective, randomized, single blind protocol patients were allocated to receive either a RIPC protocol (consisting of three 5 min cycles of intermittent left upper arm ischemia induced by inflating a blood pressure cuff to >200 mmHg with 5 min of reperfusion in between) or no intervention. Cardiac troponin I (cTnI) concentration was measured preoperatively and over 72 hours (h) postoperatively. Mean postoperative cTnI release was significantly less at 6, 12, 24, and 48 h after surgery (ANCOVA; P<0.0001) in the RIPC group (N=25) than in controls (N=22). Peak postoperative cTnI concentration was also significantly less following RIPC (9.1 ng/mL ±4.4 vs. 13.3±7.6, P<<med>0.03).
Conclusions: Thus, RIPC by simple repetitive inflation of a cuff around the left upper arm before surgery enhances myocardial protection in patients undergoing CABG surgery with antegrade crystalloid (Bretschneider) cardioplegia.