No Cardioprotective Benefit of Ischemic Postconditioning in Patients With ST‐Segment Elevation Myocardial Infarction

BACKGROUND: Postconditioning is a potential cardioprotective strategy that has demonstrated conflicting and variable reductions in infarct size in human trials. OBJECTIVES: To determine whether postconditioning could increase the extent of myocardial salvage in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (PPCI). METHODS: One hundred two patients (aged 57 ± 11 years; 88% male) were randomly assigned to a postconditioning or standard protocol. Cardiovascular magnetic resonance imaging was performed 3 days after PPCI to measure the volumetric extent of myocardial necrosis and the area at risk. RESULTS: With similar time-to-reperfusion (170 ± 84 minutes in the postconditioning group vs. 150 ± 70 minutes in the standard group, P = 0.22), the myocardial salvage index was not significantly different between the postconditioned group and the control group, averaging 42 ± 22% vs. 33 ± 21%, respectively (P = 0.08). Furthermore, postconditioning was not associated with a smaller infarct size compared to controls (13 ± 7 g/m(2) vs. 15 ± 8 g/m(2), respectively, P = 0.18). CONCLUSIONS: Postconditioning does not significantly increase myocardial salvage or reduce infarct size in patients with STEMI undergoing PPCI. However, the possibility of a more modest impact of postconditioning cannot be excluded with our sample size.