Evaluation Of Prognostic Factors And Proteomic Analysis Of Biomarkers In Patients With Acute Coronary Syndromes

Objective:The prognosis of patients with acute coronary syndromes (ACS) varieswidely, and a number of biochemical markers have been shown to predict short-term andlong-term outcomes, but most have limitations in clinical sensitivity and/or specificity. Thestudy was to investigate and evaluate the prognostic factors of ACS, identify potentialpredictors through proteomic analysis, detect circulating fragments of N-terminalpro-B-type natriuretic peptide (NT-proBNP), and finally analyze the associations of themolecular forms of NT-proBNP with adverse outcomes in ACS.Methods: The study consists of three parts.(1) Two independent patient cohorts whowere admitted to the Chinese PLA General Hospital with chest pain and suspected ACSwere recruited. Medical data were collected. The first cohort was followed-up in30daysand3years after discharge, and the second cohort in2months and1year after discharge.Major adverse cardiovascular events (MACE) included the primary endpoint (cardiacdeath and non-fatal myocardial infarction) and the secondary endpoint (rehospitalizationwith unstable angina and ischemic stroke).A series single and multiple factor analysis wereperformed to evaluate associations between MACE and several risk factors.(2) Atotal of409patients with ACS were randomly selected from the first cohort. Serum proteomicanalysis was performed by surface-enhanced laser desorption/ionization time-of-flight(SELDI-TOF) mass spectrometry (MS). Associations of protein spectra with MACE wereevaluated by cluster analyses and COX proportional hazards regression models.(3) Anewly developed method of MS-based detection combined with immunocapture usingcommercial anti-NT-proBNP antibodies was performed to detect the different circulatingforms of NT-proBNP in200patients with ACS from the second cohort.Associations ofcirculating forms of NT-proBNP and total NT-proBNP with cardiovascular events werecompared bysingle andmultiple factor analysis. Results:(1) A total of1023and1039patients were included in the first and secondcohorts, and770and777of them were diagnosed as ACS, respectively. The incidenceof30days and3years MACE were8.3%and35.6%in the first cohort, and the incidence of2months and1year MACE were16.2%and35.6%in the second cohort.The factorsassociated with short-term outcomes and with long-term outcomes were different in bothcohorts. After multivariableadjustment, the short-term outcomes were positively associatedwith the proportion of patients with cardiac function≥3or left ventricularejectionfraction≤40%, the levels of NT-proBNP, creatine kinase MB fraction, and troponin T(P<0.05); while the long-term outcomes were only associated with cardiac function(P<0.05).(2) A m/z4714.39peak was associated with an increased incidence of3yearsoutcomes. In multivariable analysis, the m/z4171.39peak showed an independentcorrelation with3years (over30days) outcomes (HR=2.33,95%CI=1.23-4.39, P=0.009for the fourth versus first quartile).(3) The glycosylation of NT-proBNP combined withproteolysis were the main form in serum of ACS patients. The ratio of processed peptideNT-proBNP(3-76) and four sites glycosylation with N-terminal1-3and76proteolysis wasnegatively associated with the short-and long-term outcomes (P<0.05). The associations ofthe ratio with adverse outcomes remained significant in multivariate analyses(P<0.05).Conclusions:The factors associated with the short-term outcomes and with thelong-term outcomes were different. The m/z4174.39peak may be a member of the CXCchemokine family and provided additional prognostic value in ACS. Furthermore, theglycosylated NT-proBNP was better than total NT-proBNP levels as a biomarker forpredicting outcomes. The study provided methods for the research of biomarkers and itscirculating forms. The findings also provided additional information about the pathogenicmechanism and the possible diagnostic and therapeutic targets in ACS.