Abstract:

Objective To investigate the predictive value of small and dense low-density lipoprotein cholesterol（sd-LDL-C）/low-density lipoprotein cholesterol（LDL-C） ratio for in-stent restenosis in patients with acute myocardial infarction（AMI） after interventional therapy. Methods A total of 145 patients with AMI who underwent percutaneous coronary intervention（PCI） in Inner Mongolia Autonomous Region People's Hospital from August 2020 to August 2021 were enrolled. The clinical data of all the patients were collected，and the levels of serum total cholesterol（TC），triglyceride（TG），LDL-C，high-density lipoprotein cholesterol（HDL-C），sd-LDL-C and C-reactive protein（CRP） were determined at admission，and the ratio of sd-LDL-C/LDL-C was calculated. The patients were followed up for 1 year after PCI，and the occurrence of in-stent restenosis in AMI patients was evaluated according to the results of coronary angiography. The correlation between sd-LDL-C/LDL-C ratio and in-stent restenosis in AMI patients was evaluated by point two-column correlation analysis. Logistic regression analysis was used to evaluate the risk factors of in-stent restenosis in AMI patients. Receiver operating characteristic（ROC） curve was used to evaluate the efficacy of sd-LDL-C/LDL-C ratio in judging in-stent restenosis in AMI patients. Results During the 1-year follow-up after PCI，4 patients were lost to follow-up. Among the remaining 141 patients，20 patients（14.18%） had in-stent restenosis（stenosis group），and the other 121 patients without stenosis were enrolled into non-stenosis group. The LDL-C，sd-LDL-C and LDL-C/sd-LDL-C ratio in stenosis group were higher than those in non-stenosis group（P<0.05）. There was no statistical significance in HDL-C and CRP between the 2 groups（P>0.05）. The occurrence of in-stent restenosis in AMI patients was positively correlated with sd-LDL-C，LDL-C and sd-LDL-C/LDL-C ratio（r=0.441，0.351 and 0.347，P<0.001）. The increased sd-LDL-C，LDL-C and sd-LDL-C/LDL-C ratio were risk factors for in-stent restenosis in AMI patients（P<0.05）. The area under curve（AUC） of serum sd-LDL-C，LDL-C and sd-LDL-C/LDL-C ratio in judging in-stent restenosis in AMI patients were 0.709，0.706 and 0.750，respectively. Conclusions The levels of sd-LDL-C and LDL-C are related to the occurrence of in-stent restenosis after PCI in AMI patients. The ratio of sd-LDL-C/LDL-C may be used as an index to judge in-stent restenosis.

Key words: Small and dense low-density lipoprotein cholesterol, Low-density lipoprotein cholesterol, Percutaneous coronary intervention, In-stent restenosis, Acute myocardial infarction