Relationship Between Red Blood Cell Distribution Width And The Severity As Well As Prognosis Of Acute Coronary Syndrome

Background:Red blood cell distribution width(RDW) is a measurement of the variability in the size of circulating red blood cells,which is typically used to differentiate between types of anemia.In2007,higher RDW values as an independent prognostic markers in patients with chronic heart failure was first reported by Felker.At present,a large number of clinical studies have shown that RDW will help evaluate the prognosis of patients with heart failure and coronary heart disease.Also recently,a new hypothesis has been proposed that erythrocytes may play an active role in atherosclerotic plaque growth and rupture leading to acute coronary syndromes.Histopathology studies showed that the necrotic lipid core of advanced atherosclerotic plaques contains erythrocyte membranes.The membrane of circulating erythrocytes (CEM) level determines plaque progression.Further studies have shown that CEM levels were positive associated with RDW values independently.Therefore,we propose that RDW may be associated with atherosclerosis plaque progression.In this study we analyzed the association of RDW with the Gensini score,which reflect the severity of coronary artery lesions,to verify whether the hypothesis is established.Objective:The association of RDW with Gensini score in patients with ACS was analyzed to assessing the predictive value of RDW for the severity of coronary artery lesions. To assess the prognostic contribution of RDW for ACS.Methods:From January2011to March2013,330ACS patients in the Department of Cardiology in the Second Hospital of Tianjin Medical University were collected. According to exclusion and inclusion criteria,104cases including patients with stable angina pectoris and patients without coronary lesion by coronary angiography were chosen as control group.ACS patients were followed-up to March2013,the major clinical outcomes including refractory angina,recurrent myocardial infarction,new onset heart failure and all-cause of death.Finally309cases of ACS were enrolled in this study,including94patients with unstable angina pectoris,55 with Non-ST-segment elevation myocardial infarction and160with ST-segment elevation myocardial infarction.RDW,hemoglobin,red blood cell count,white blood cell count, mean corpuscular volume,hematocrit values,platelet count,mean platelet volume, blood urea nitrogen,serum creatinine,uric acid,troponin I,alanine aminotransferase enzyme,aspartate aminotransferase,albumin and blood lipids were obtained.Detailed informations were recorded including age,gender,history of smoking,hypertension,diabetes mellitus,stroke and the situation of heart function. Gensini score was calculated based on coronary angiography,the correlation of Gensini score with RDW was analyzed.Multivariate logistic regression analysis was used to evaluate the independent risk factors of severe coronary lesions.We using the receiver-operating characteristic curve to assess the prognostic contribution of RDW for ACS.The results were analyzed comparatively between the higher RDW group and the lower.Results:1.ACS group in age,the proportion of male,smoking history,history of diabetes and stroke,white blood cell count,RDW,blood urea nitrogen,serum creatinine,uric acid, ALT,AST and troponin I were significantly higher than those in the control group(P <0.01),while albumin,left ventricular ejection fraction were significantly lower than those in the control group(P<0.01).2.The ACS subgroups had significantly higher RDW and Gensini score compared with control group (P<0.05).NSTEMI and STEMI group were significantly higher in Gensini score than those in UAP group(P<0.01).3.With the patients’age increased,the Killip’s heart function classification level increased accordingly(P<0.01).LVEF obviously reduced in the Killip’s Ⅱ and Ⅲ group than that in the Killip’s I group,however,the RDW value increased significantly with the deterioration of cardiac function(P<0.05).4.Spearman correlation analysis showed that RDW levels were positively associated with age,serum creatinine,blood urea nitrogen and Gensini score while negatively correlated with albumin,hemoglobin and LVEF.There also had correlation between RDW and Gensini score among the subgroups of ACS,in the UAP group(r=0.272, P <0.01),and in the AMI group(r=0.307,P<0.01). Multivariable linear regression analysis showed that age and Gensini score were associated with RDW values independently from possible confounders (hemoglobin, albumin,serum creatinine, blood urea nitrogen,LVEF)(P<0.01).5.In Multivariate Logistic regression analysis,history of diabetes,RDW,UA and AST were observed to be independent predictors for severe coronary lesions (Gensini score>20).6.Until March2013,among21of the330patients with ACS were lost to follow-up,the rate of following-up was93.6%.There were26(8.41%) all-cause of death,17(5.50%)recurrent myocardial infarction,38(12.30%) new onset heart failure and39(12.62%)intractable angina.In the receiver operating characteristic curve analysis,an RDW value of12.65%was identified as an effective cut-off point in ACS of the new onset heart failure (area under curve=0.757,95%CI:0.671-0.842),an RDW value of more than12.65%yielded a sensitivity of65.8%and a specificity of73.1%.While an RDW value of12.75%was identified as an effective cut-off point in ACS of all-cause of death(area under curve=0.800,95%CI:0.686-0.914),an RDW value of more than12.75%yielded a sensitivity of73.1%and a specificity of78.4%.7.The RDW≥12.7%group had significantly higher age,BUN,SCr and UA than those in the RDW<12.7%group (P<0.01),while LVEF was significantly lower than the latter(.P<0.05).New onset heart failure and all-cause of death were significantly higher in the higher RDW group than those in the low(P<0.01).Conclusion:1. Age and Gensini score were independent predictors for RDW value.2.RDW levels were negatively correlated with cardiac function and renal function. Patients with higher RDW values had worse heart function and renal function.3.The independent risk factors for predicting severe coronary lesions including RDW, diabetes,UA and AST.4.There is some predictive value of RDW for all-cause of death and new onset heart failure.