Ischemic postconditioning does not improve peripheral endothelial function in ST-segment elevation myocardial infarction patients

Abstract

The purpose of this study was to determine whether ischemic postconditioning (IPC) could improve peripheral endothelial function in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Of 102 patients randomly assigned to an IPC or standard protocol to study infarct size utilizing cardiovascular magnetic resonance imaging, 84 patients had peripheral endothelial function assessed with brachial ultrasound measures and peripheral arterial tonometry (PAT) during reactive hyperemia 3 days after PCI. Overall IPC was not associated with a smaller infarct size compared to controls, though there was a trend towards greater myocardial salvage with IPC. Patients randomized to IPC (n=43; age 56 ± 11 years; 85% male) and standard protocol (n=41; age 56 ± 10 years; 88% male) underwent endothelial function assessment. Flow mediated vasodilatation was not significantly greater in the IPC group than in the standard group (7.4 ± 4.9% versus 6.6 ± 4.0% respectively, p=0.40) nor was peak hyperemic velocity-time integral (78 ± 26 cm versus 71 ± 30 cm respectively, p=0.28). Similarly, the PAT hyperemic ratio was not significantly greater in the IPC group than in the standard group (2.0 ± 0.9 versus 1.8 ± 0.6 respectively, p=0.14). In conclusion, IPC did not improve early peripheral endothelial function in patients with STEMI undergoing primary PCI.

Keywords: endothelial function; flow mediated vasodilatation; peripheral arterial tonometry; postconditioning; reperfusion injury.