[Effects of preconditioning and postconditioning on emergency percutaneous coronary intervention in patients with acute myocardial infarction]

Abstract

Objective: Postconditioning is a novel approach to myocardial protection during ischemia reperfusion. To investigate the effects of preconditioning and postconditioning on coronary blood flow velocity and prognosis of the patients with acute myocardial infarction (AMI) undergoing emergency percutaneous coronary intervention (PCI).

Methods: Ninety-six patients with AMI underwent revascularization by primary PCI within 12 h after the onset. The 35 patients with preinfarction angina were treated with preconditioning (Precond group). The other 61 patients without preinfarction angina were randomized into two groups: 29 patients undergoing PCI without postconditioning [reinfusion (IR) group], and 32 patients undergoing PCI with postconditioning (3 cycles of reinfusion for 30 s/re-occlusion for 30 s beginning within 1 minute after reinfusion, Postcond group). Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) was used to evaluate the velocity of coronary blood after PCI. Creatine phosphokinase (CK), CK-MB, and malondialdehyde (MDA) were measured before and after PCI. Wall motion score index (WMSI) was assessed by two-dimensional echocardiography before and 8 weeks after angioplasty.

Results: There were no significant differences between the three groups with regard to age, sex, presence of angiographically visible collaterals, and elapsed time from the onset of symptoms until perfusion. The CTFC values of the patients of the Precond and Postcond groups were both 27 +/- 6, 27 +/- 6, both significantly faster than that of the patients of the IR group (31 +/- 7, both P < 0.05). The CK peak values of the Precond and Postcond groups were 1242 U/L +/- 801 U/L and 1237 U/L +/- 813 U/L respectively, both significantly lower than that of the IR group (1697 U/L +/- 966 U/L, P < 0.05). The CK-MB peak values of the Precond and Postcond groups were 122 U/L +/- 78 U/L and 117 U/L +/- 76 U/L respectively, both significantly lower than that of the IR group (172 U/L +/- 93 U/L, P < 0.05). The MDA of the Precond and Postcond groups at all time points were all significantly lower than that of the IR group (all P < 0.05). The WMSI values 8 weeks after PIC of the Precond and Postcond groups were 1.2 +/- 0.2, and 1.2 +/- 0.2 respectively, both significantly lower than that of the IR group (1.4 +/- 0.3, P < 0.05).

Conclusion: A simple and operative procedure to improve the coronary blood flow velocity and heart function and reduce the production of free oxygen radicals, postconditioning can be used clinically widely so as to better the prognosis of AMI.