关键词: 心肌梗死, 中性粒细胞, 淋巴细胞, 血细胞比容, 预后, 影响因素分析

Abstract: Background　Neutrophil-to-lymphocyte ratio （NLR） and mean platelet volume （MPV） are novel inflammatory response markers that can be used to predict the prognosis of patients with acute ST-segment elevation myocardial infarction （STEMI）.However，there are few studies exploring the clinical value of NLR combined with MPV in predicting the prognosis of STEMI patients.Objective　To investigate the predictive value of NLR combined with MPV in the occurrence of nosocomial major adverse cardiovascular events （MACE） after emergency percutaneous coronary intervention （PCI） in patients with acute STEMI.Methods　A total of 516 consecutive patients diagnosed as STEMI with emergency PCI in the First Affiliated Hospital of the Medical College，Shihezi University from October 2015 to September 2018 were selected.According to the median peripheral blood NLR and MPV on emergency admission，our cohort was divided into low NLR combined with low MPV group（NLR≤2.51 and MPV≤10.70 fl，n=135），low NLR and high MPV group（NLR≤2.51 and MPV>10.70 fl，n=123），high NLR combined with low MPV group（NLR>2.51 and MPV≤10.70 fl，n=137），high NLR combined with high MPV group（NLR>2.51 and MPV>10.70 fl，n=121）.Our cohort was divided into high-risk group（GRACE score>140 points，n=212），medium-risk group （108 <GRACE score≤140 points，n=222），low-risk group （GRACE score ≤108 points，n=82） according to baseline GRACE score.According to the occurrence of MACE during hospitalization，our cohort was divided into MACE group （n=71） and non-MACE group （n=445）.Comparisons of pre-PCI clinical and laboratory data，post-PCI medication，laboratory and color Doppler echocardiography data within 24 hours after PCI were performed by NLR with MPV，and the incidence of MACE，respectively.Logistic regression analysis was used to investigate the influencing factors of post-PCI MACE.ROC curve analysis was used to evaluate the value of NLR，MPV and NLR combined with MPV in predicting the occurrence of post-PCI MACE.The correlation between NLR and MPV before PCI was analyzed.The pre-PCI NLR and MPV were compared by GRACE score.Compared the incidence of no reflow and in-hospital MACE in hospital after PCI by NLR with MPV，and GRACE score，respectively.Results　Low NLR combined with high MPV group showed lower rate of pre-infarction angina and higher mean GRACE score than low NLR combined with low MPV group （P<0.05）.High NLR combined with low MPV group showed higher prevalence of hypertension and higher mean GRACE score，and lower rate of pre-infarction angina than than other three groups stratified by NLR and MPV（P<0.05）.Low NLR combined with high MPV group had higher mean HCT，and higher mean peak values of HCT and TnT，and lower mean HDL-C and CRP than low NLR combined with low MPV group（P<0.05）.High NLR combined with low MPV group showed higher mean neutrophil count，NLR and MPV，and higher mean peak values of CK-MB and TnT，as well as lower mean lymphocyte count and LVEF than low NLR combined with high MPV group（P<0.05）.In comparison with high NLR combined with high MPV group，low NLR combined with low MPV group had lower mean neutrophil count，NLR，MPV，peak CK-MB and peak TnT，and CRP，and higher mean lymphocyte count and LVEF（P<0.05），low NLR combined with high MPV group showed lower mean neutrophil count，NLR，MPV，peak CK-MB and peak TnT，Scr，HDL-C and CRP，as well as higher mean lymphocyte count and LVEF（P<0.05），and high NLR combined with low MPV group demonstrated lower mean NLR，MPV，peak TnT，and CRP，and higher mean lymphocyte count and LVEF（P<0.05）.Multivariate Logistic regression analysis showed that heart rate （OR=1.025），Killip classⅡ-Ⅳ（OR=4.231），GRACE score （OR=1.031），NLR （OR=2.716），MPV （OR=2.106），TnT peak （OR=1.215），CRP （OR=1.011），LVEF （OR=0.923） were independent influencing factors for the occurrence of in-hospital MACE in STEMI patients （P<0.05）.The AUC of NLR，MPV and NLR combined with MPV for predicting MACE in STEMI patients after PCI was 0.670〔95%CI（0.609，0.730）〕，0.678〔95%CI （0.616，0.741）〕，and 0.732〔95%CI （0.671，0.791）〕，respectively.There was significant difference between NLR with MPV and NLR or MPV alone in predicting AUC of post-PCI MACE （P=0.012，0.023，respectively）.NLR was positively correlated with MPV （rs=0.168，P=0.008）.Mean NLR and MPV increased successively in low-risk，medium-risk，and high-risk groups（P<0.05）.Low NLR combined with low MPV group showed lower incidence of no-reflow and in-hospital MACE after PCI compared with other three groups stratified by NLR and MPV （P<0.05）.The incidence of no-reflow and in-hospital MACE in both high NLR combined with low MPV and high NLR combined with high MPV groups was higher than that of low NLR combined with high MPV group（P<0.05）.High NLR combined with high MPV group showed higher incidence of no-reflow and in-hospital MACE than high NLR combined with low MPV group （P<0.05）.The incidence of no-reflow and in-hospital MACE in both low-risk and medium-risk groups was lower than that in the high-risk group （P<0.05）.Conclusion　High NLR and high MPV at the early stage of admission are independent risk factors for nosocomial MACE in patients with STEMI after PCI.And NLR combined with MPV can more effectively predict the occurrence of in-hospital MACE，which can be used as a good indicator for prognosis evaluation of early STEMI patients.

Key words: Myocardial infarction, Neutrophils, Lymphocytes, Hematocrit, Prognosis, Root cause analysis