Objective To evaluate the short-time effects, angiographic characteristics, and the clinical outcome of preinfarction angina in patients with first acute myocardial infarction (AMI) after emergency primary percutaneous coronary intervention (PCI). And evaluate the influence of diabetes mellitus to preinfarction angina.
Methods The clinical data of 130 patients with AMI hospitalised from January 2006 to December 2008, who underwent emergency PCI within 12 h after the onset of AMI, including 54 cases complicated with diabetes mellitus (Group DM) and 76 cases without diabetes (non-diabetes mellitus group, Group ND). 76 Patients in group ND (without diabetes) were divided into group A (with preinfarction angina, n=40) and group B (without preinfarction angina, n=36). Another 54 patients in group DM (with diabetes) were divided into group C (with preinfarction angina, n=28) and group D (without preinfarction angina, n=26). The basic clinical characteristics, baseline demographic, angiographic and procedural details in these four groups were similar. Myocardial enzyme was continuously measured. Clinical and angiographic features, the extent of coronary artery lesions were analysed. The incidence of malignant arrhythmia, heart failure, cardiogenic shock, and the rate of MACE (major adverse cardiac event, including cardiac death, reinfarction, reconstruction of ischaemic target vessel) in hospitalisation were observed. The coronary collateral circulation and spontaneous coronary recanalisation (SR) of infarct related artery (IRA) in coronary artery disease were also analysed.
Results 1. There were no significantly difference between baseline clinical document and the time of revasculatisatioin of IRA in each group (p>0.05). 2. The peak value of creatine kinase MB (CK-MB) was significantly lower in group A than that in group B (p<0.05). And there was no significantly difference between each group (p>0.05). 3. The character being analysed during CAG 3.1. The characteristic of coronary artery disease 3.1.1 The incidence of multi-branch lesions were significantly lower in group A than that in group D (p<0.05), while, there was no significiant difference in other groups (p>0.05). 3.1.2. The score of Gensini to evaluate coronary artery angusty in group A was significantly lower than that in group B (p<0.05), C (p<0.05) and D (p<0.01), but there weren't significant differences among group B, C and D (p>0.05). 3.1.3. There were no significantly difference of spontaneous coronary recanalisation (SR) of infarct related artery (IRA), coronary collateral circulation (CCC) in coronary artery disease, diffuse affection and the number of occlusion vascular among four groups (p>0.05 for these comparisons). 3.2. The evaluation during PCI 3.2.1. There was no significant differences in PCI immediate success rate during hospitalisation, the number of stents implented into IRA, the blood flow after the plenting of stents and the phenomenon of no-reflow among four groups (p>0.05). 3.2.2. The blood flow of the IRA before the plenting of stents was significantly higher in group A than that in group B (p<0.05). 4. The clinical outcomes of patients in the near future after PCI during hospitalisation. 4.1. There were no significantly difference of malignant arrhythmia, total cardiac mortality rates, acute heart failure and cardiogenic shock (KillipII∼IV), reconstruction of ischaemic target vessel among four groups (p>0.05). 4.2. The accidence of reinfarction and stent thrombosis was significantly lower in group. A than those in group B (p<0.05).
Conclusion Preinfarction angina can reduce myocardial infarct size and the extention of AMI, and have beneficial effects on blood flow of IRA before PCI. It can reduce not only the happening frequence of reinfarction but also the stent thrombosis. So preinfarction angina can improve short-time prognosis in AMI. But such beneficial effects of preinfarction angina were not observed in diabetic patients, suggesting that diabetes might prevent the protection effects of ischaemic preconditioning.