Abstract:

Objective To investigate the correlation between small and dense low-density lipoprotein cholesterol（sd-LDL-C） and acute coronary syndrome（ACS） with long-term adverse cardiovascular events in ACS patients. Methods Totally，149 ACS patients who received coronary artery stent implantation treatment were enrolled，which included 32 cases of acute myocardial infarction（AMI）（AMI group） and 117 cases of unstable angina pectoris（UAP）（UAP group）. Totally，50 healthy subjects were enrolled as control group. Total cholesterol（TC），triglyceride（TG），low-density lipoprotein cholesterol（LDL-C），high-density lipoprotein cholesterol（HDL-C），apolipoprotein（apo） A1，apo B and lipoprotein（a）[Lp（a）] were determined，and non-high-density lipoprotein cholesterol（non-HDL-C） was calculated. Logistic regression analysis was used to evaluate the risk factors for the occurrence of ACS. All the patients were followed up for 36 months. Kaplan-Meier survival curve was used to evaluate the incidence of long-term adverse cardiovascular events in ACS patients with different levels of sd-LDL-C. Cox regression analysis was used to evaluate the risk of major adverse cardiovascular events（MACE） and recurrent ACS in ACS patients with different levels of sd-LDL-C. Results The levels of serum TC，TG，LDL-C，non-HDL-C，apo B and sd-LDL-C in AMI and UAP groups were higher than those in control group（P<0.05），while the levels of serum HDL-C were lower than those in control group（P<0.05）. There was no statistical significance in apo A and Lp（a） among the 3 groups（P>0.05）. The results of Logistic regression analysis showed that sd-LDL-C was a risk factor for the occurrence of ACS [odds ratio（OR）=67.184，95% confidence interval（CI）5.284-854.213]. Based on the occurrence of adverse prognosis in ACS patients，receiver operating characteristic（ROC） curve was drawn，and all the ACS patients were classified into 2 groups，low sd-LDL-C group and high sd-LDL-C group，with the optimal cut-off value of 1.145 mmol/L. Kaplan-Meier survival curve showed that patients with high sd-LDL-C levels had a higher incidence of long-term adverse cardiovascular events compared to patients with low sd-LDL-C levels（P<0.05）. Cox regression analysis indicated that an increasing in sd-LDL-C had independent prognostic value for adverse cardiovascular events（total long-term adverse cardiovascular events：HR=4.376，95%CI 2.178-8.791；MACE：HR=3.848，95%CI 2.419-6.120；recurrent ACS：HR=4.067，95%CI 2.002-8.262）. Conclusions The sd-LDL-C has clinical value in early prevention and long-term prognosis evaluation of ACS.

Key words: Small and dense low-density lipoprotein cholesterol, Acute coronary syndrome, Risk factor, Major adverse cardiovascular event