Study On White Blood Cell Count And Cardiovascular Mortality In Elderly Patients With Acute Myocardial Infarction

Background:Inflammation is involved in the occurrence and development of cardiovascular atherosclerosis.As one of the important markers of inflammation,leukocytes play an important role in the pathogenesis of coronary heart disease(CAD).Previous studies have shown that leukocytes can predict the prognosis of patients with CAD.However,there are few studies on its predictive value in the risk of death in elderly patients with acute myocardial infarction(AMI).Therefore,the main aim of the study is to find the relationship between leukocyte parameters and cardiovascular mortality in elderly people with AMI.Methods:in this single-center,prospective study,we selected 1299 patients with AMI in Fuwai hospital from January 2012 to December 2018,whose age is over 65 years old.The levels of white blood cell count(WBC),neutrophil(NEU),monocyte(MON)and lymphocyte(LYM)were measured in all selected patients at baseline.The NEU/LYM ratio(NLR),MON/LYM ratio(MLR)and(MON+NEU)/LYM ratio(NMLR),were calculated.WBC,NEU,LYM,NLR,MLR and NMLR were divided into three subgroups according to the ternary level,namely group 1(low level group),group 2(middle level group)and Group 3(high level group).Then,all patients were followed up by professionally trained medical staff.The content of follow-up is mainly cardiovascular events.During the follow-up,307 cases(29%)of CVE due to cardiovascular death were taken as event group,and 992 cases survived as non-event group.The relationship between white blood cell count and death from cardiovascular disease was analyzed by Kaplan-Meier and Cox proportional hazard model.Results:During the average follow-up period of 2.2 years,315 cases(29%)of death from cardiovascular disease were recorded.Compared with the non-event group,the levels of WBC,NEU,NLR,MLR and NMLR in the event group were significantly higher than those in the non-event group.Multivariate Cox proportional hazard regression analysis for correcting traditional cardiovascular risk factors showed that NEU,LYM,NMLR and NLR had independent predictive value for risk of cardiovascular death in elderly patients with AMI(HR=1.65,95%CI:1.17%CI:0.42%CI:0.42%CI:1.37%CI:2.83).HR=2.05,95%CI:1.40±2.99,P<0.01),and NMLR and NLR were the two most significant predictors of cardiovascular death in elderly AMI patients.Adding NMLR and NLR,statistics to the original COX prediction model is[0.038(0.020-0.0.069),p=0.002)and[0.037(0.021-0.068),p=0.002],respectively).In addition,adding NMLR and NLR,statistics to the C-ACS risk score model is[0.079(0.041-0.114),p<0.001)and[0.077(0.040-0.111)]respectively.P<0.001],therefore,C statistical analysis shows that both NMLR and NLR can significantly improve the predictive value of the model.Conclusions:This study found that most leukocyte parameters(NEU,LYM,NMLR and NLR)can predict risk of cardiovascular death in elderly people with AMI,and the predictive value of NMLR and NLR may be greater,suggesting that more attention should be paid to the changes of these indexes in elderly patients with AMI.