Postconditioning the Human Heart in Percutaneous Coronary Intervention

Background: It has been proved in animal models that postconditioning (PC) could attenuate reperfusion injury. But there are not many clinical studies on the application of PC. Hypothesis: Four cycles of 1-minute balloon inflation and deflation, following initial balloon reperfusion in ST-segment elevation myocardial infarction (MI) but before stenting, might improve clinical outcomes compared with primary percutaneous coronary intervention (PCI) alone. Methods: Forty-three patients diagnosed with acute MI were randomly assigned to 2 groups: the control group (n = 20) and the PC group (n = 23). Blood samples were obtained and assayed for creatine kinase MB (CK-MB) and high-sensitive C-reactive protein. Electrocardiogram, echocardiography, and rest technetium Tc 99m-sestamibi (99mTc-MIBI) myocardial perfusion single-photon emission computed tomography (SPECT) were performed. Results: The control group presented with higher peak CK-MB as compared with the PC group (351.9 +/- 153.6 vs 247.7 +/- 118.3 U/L, P = 0.028) as well as the area under the curve (AUC) of CK-MB (8040 3358 VS 5955 2509, P = 0.04). After PCI, PC was associated with a lower level of hs-CRP in comparison with the control group (5.5 +/- 4.5 vs 9.5 +/- 5.2 mg/L, P = 0.019). More patients in the PC group had complete ST-segment resolution than did patients in the control group (82.6% vs 45.0%, P = 0.049). Left ventricle ejection fraction was better in the PC group than in the control group (0.57 +/- 0.09 vs 0.47 +/- 0.11, P = 0.002). Compared with the control group, PC greatly reduced infarct size, by 46% as measured by SPECT (13 +/- 11.2% VS 24.2 +/- 10.6%, P = 0.002). Conclusions: This study indicated that PC in emergent PCI was a valuable modification of primary PCI.