TNNI3 and ischemia: In this trial, morphine-induced postconditioning reduced postoperative peak release of cTnI at the post-reperfusion time point of 4 hours by 31.6% compared to the control group and total cTnI release by 47.7% during the first postoperative 8 hours, suggesting that morphine-induced postconditioning may help to reduce myocardial injury induced by ischemia.