This study investigates the protective effect of postconditioning on the human heart during coronary angioplasty for acute myocardial infarction (AMI). Postconditioning involves brief episodes of ischemia-reperfusion performed within 1 minute of reflow after direct stenting. Thirty patients undergoing coronary angioplasty for ongoing AMI were randomly assigned to either a control or a postconditioning group. The postconditioning group received four episodes of 1-minute inflation and 1-minute deflation of the angioplasty balloon. The results showed a significant reduction in infarct size, with a 36% decrease in the area under the curve of creatine kinase release, and an increased blush grade, indicating better myocardial reperfusion. No adverse events were observed in the postconditioning group. The study suggests that postconditioning during coronary angioplasty can protect the human heart and reduce infarct size, offering a potential new therapeutic approach for AMI.This study investigates the protective effect of postconditioning on the human heart during coronary angioplasty for acute myocardial infarction (AMI). Postconditioning involves brief episodes of ischemia-reperfusion performed within 1 minute of reflow after direct stenting. Thirty patients undergoing coronary angioplasty for ongoing AMI were randomly assigned to either a control or a postconditioning group. The postconditioning group received four episodes of 1-minute inflation and 1-minute deflation of the angioplasty balloon. The results showed a significant reduction in infarct size, with a 36% decrease in the area under the curve of creatine kinase release, and an increased blush grade, indicating better myocardial reperfusion. No adverse events were observed in the postconditioning group. The study suggests that postconditioning during coronary angioplasty can protect the human heart and reduce infarct size, offering a potential new therapeutic approach for AMI.