The Association Of Platelet-to-lymphocyte Ratio With In-hospital Major Adverse Cardiovascular Events And The Coronary Artery Stenosis Degree In Patients With Acute Myocardial Infarction

Background and Objective: The platelet-to-lymphocyte ratio(PLR)has recently emerged as a novel potential inflammatory biomarker and has been shown to be significantly associated with coronary atherosclerotic heart disease.This study aimed to explore the association of PLR with in-hospital major adverse cardiovascular events(MACEs)and the coronary artery stenosis degree assessed by the Gensini score(GS)in patients with acute myocardial infarction(AMI)undergoing coronary angiography(CAG),and evaluate the predictive value of PLR for in-hospital MACEs and the coronary artery stenosis degree.Methods: Data of 502 AMI patients consecutively treated at the Affiliated Hospital of Qingdao University(Qingdao,China)and underwent coronary angiography from August 2017 to December 2018 were enrolled in this study,including 372 males and 130 females.The baseline clinical data,angiographic characteristics and laboratory parameters were collected.According to the presence of in-hospital MACEs,the enrolled patients were divided into the MACE group(n = 81)and the non-MACE group(n = 421).Further,according to tertiles of the GS,the patients were classified into three groups: the low GS group(GS ≤ 32 points,n =173),medium GS group(32 points < GS ≤ 60 points,n =169),and high GS group(60 points < GS ≤ 180 points,n =160).The main statistical methods included chi-square test,non-parametric Mann-Whitney U-test,Kruskal-Wallis H-test,logistic regression and receiver operating characteristic curve(ROC curve).The association of PLR with in-hospital MACEs and the coronary artery stenosis degree was explored,and the predictive value for in-hospital MACEs and severe coronary artery stenosis of PLR was also evaluated.Results:1.The PLR in the MACE group was significantly higher than that in the non-MACE group(179.43 [132.84,239.74] vs.116.11 [87.98,145.45],P < 0.001).In addition,compared with the non-MACE group,the length of hospital stay,GS,neutrophil count,platelet count,and neutrophil-to-lymphocyte ratio(NLR)were significantly higher in the MACE group,while the left ventricular ejection fraction(LVEF)and lymphocyte count were significantly lower.The differences were statistically significant(P < 0.05).2.Among the three groups based on the GS,there were significant differences in PLR among the tertiles of GS(110.05 [84.57,139.06] vs.119.78 [98,44,157.98] vs.140.00 [102.27,191.83],P < 0.001).The LVEF,lymphocyte count and high-density lipoprotein cholesterol(HDL-C)level in the high GS group were significantly lower than those in the low GS group and the medium GS group.The prevalence of diabetes mellitus,platelet count,NLR,low-density lipoprotein cholesterol(LDL-C),LDL-C/HDL-C in the low GS group were significantly lower than those in the medium GS group and high GS group.The differences were all statistically significant(P < 0.05).3.PLR was demonstrated to be an independent risk factor of in-hospital MACEs(OR: 1.012,95% CI: 1.006–1.018,P < 0.001)and severe coronary artery stenosis(GS > 60)(OR: 1.004,95% CI: 1.002–1.009,P = 0.042)according to the univariate and multivariate logistic regression analyses.4.The results of ROC curves indicate that PLR has good predictive value for in-hospital MACE and severe coronary artery stenosis in patients with AMI.The cutoff value of PLR for predicting the occurrence of in-hospital MACEs was 151.28 with a sensitivity of 66.7% and a specificity of 78.1%(AUC: 0.786,95% CI: 0.730–0.842,P < 0.001),and a PLR of 139.31 was also identified to be an effective cutoff point for detecting severe coronary artery stenosis(GS > 60 points)with a sensitivity of 49.4% and a specificity of 69.6%(AUC: 0.611,95% CI: 0.556–0.666,P < 0.001).Conclusion: PLR as a novel inflammatory marker was significantly and independently associated with the occurrence of in-hospital MACEs and the coronary artery stenosis degree assessed by the GS in AMI patients.Moreover,it has good predictive value for the occurrence of in-hospital MACEs and severe coronary artery stenosis.As an easily available and inexpensive inflammatory indicator,PLR could be widely used as an efficient inflammatory biomarker for identifying high-risk patients and for guiding individualized therapy to improve the prognosis of AMI.