Comparison of plasma microRNA-1 and cardiac troponin T in early diagnosis of patients with acute myocardial infarction

BACKGROUND:Early reperfusion can effectively treat acute myocardial infarction(AMI) and reduce the mortality signif icantly. This study aimed to compare the role of plasma microRNA-1(miR-1) and cardiac troponin T(cTnT) in early diagnosis of AMI patients.METHODS:From May 2011 to May 2012,plasma samples were collected from 56 AMI patients and 28 non-AMI controls. The expression of plasma miR-1 was measured by quantitative reverse transcription-polymerase chain reaction(qRT-PCR),and the level of plasma cTnT was measured using electrochemiluminescence-based methods on an Elecsys 2010 Immunoassay Analyzer. SPSS 16.0 was used for the statistical analysis of the results. Data were expressed as mean±standard deviation unless otherwise described. The differences about clinical characteristics between the AMI patients and controls were tested using Student's t test or Fisher's exact test. The Mann-Whitney U test was conducted to compare the expression of microRNAs between the AMI patients and controls. MicroRNAs expression between different intervals of the AMI patients was compared using Wilcoxon's signed-rank test. The receiver operating characteristic(ROC) curve was established to discriminate the AMI patients from the controls.RESULTS:In the present study,the expression of plasma miR-1 was signifi cantly increased in the AMI patients compared with the healthy controls(P<0.01). The plasma miR-1 in the AMI patients decreased to the normal level at 14 days(P>0.05). The expression of plasma miR-1 was not related to the clinical characteristics of the study population(P>0.05). ROC curve analyses demonstrated that miR-1 was specifi c and sensitive for the early diagnosis of AMI,but not superior to cTnT.CONCLUSION:Plasma miR-1 could be used in the early diagnosis of AMI,but it is similar to cTnT.

Myocardial Protection with Beta Blocker Treatment in Infants with Heart Failure Due to Congenital Heart Defects and Duchenne Muscular Dystrophy

Our first intention to treat infants’ heart failure with beta blockers was to improve the clinical condition as shown in our prospective randomized trial. We only use non-selective beta blockers in these infants, carvedilol in those with left ventricular dysfunction and propranolol in those with congenital heart disease without ventricular dysfunction. Despite a significant improvement of Ross’s heart failure score, we could not convince most colleagues within the last 25 years if the concept of neurohumoral activation in heart failure is not well-established pediatric cardiology. Recently, Honghai Liu et al. published that cardiomyocyte cytokinesis failure was increased in congenital heart disease. Inactivation of the beta adreno receptors genes and administration of the beta-blocker propranolol increased cardiomyocyte division in neonatal mice, which increased the number of cardiomyocytes (endowment) and conferred benefit after myocardial infarction in adults. We currently realize that propranolol in infants with congenital heart disease not only decrease highly elevated NT-Pro-BNP values but also decrease cardiac troponin T values that may indicate myocardial injury due to neurohumoral activation. We reproduce this observation, primarily seen in infants with congenital heart disease, in an infant with Duchenne muscular dystrophy. These observations were in good accordance with current data from H. Liu et al., who showed that treatment with non-selective beta blockers early after birth might rescue cytokinesis defects and prevent heart dysfunction in adulthood in a mouse model.

Association between high-sensitivity cardiac troponin T and N-terminal pro-brain natriuretic peptide in a community based population

Background N-terminal pro-B-type natriuretic peptide （NT-proBNP） and high-sensitivity cardiac troponin T （hs-cTnT） are excellent biomarkers for detecting heart failure and subclinical myocardial injury.However,it remains unclear whether subclinical myocardial injury is associated with NT-proBNP elevation in a community based population.Methods In a community based study,levels of hs-cTnT and of NT-proBNP were determined in 1 497 participants older than 45 years.The lower detection limit of the hs-cTnT assay used in the present study was 0.003 ng/ml.The association of hs-cTnT levels and NT-proBNP levels was analyzed.Results When the subjects with undetectable （〈0.003 ng/ml）,intermediate （0.003-0.014 ng/ml）,and elevated （≥0.014 ng/ml） levels of hs-cTnT were compared （r=0.175,P 〈0.001）,a strong association between the hs-cTnT levels and NT-proBNP levels was observed （β=-0.206,P 〈0.001; β=-0.118,P 〈0.001,respectively）.In multivariable analyses,older age and hs-cTnT were positively and independently associated with NT-proBNP levels （β=0.341,P 〈0.001; β=0.143,P 〈0.001,respectively）,and male gender and the levels of eGFR were inversely and independently associated with NT-proBNP levels.When the subjects with normal or elevated NT-proBNP were analyzed separately,the hs-cTnT level was not an independent predictor for the NT-proBNP level in the normal NT-proBNP group,whereas the hs-cTnT level was the only independent predictor for NT-proBNP level in the elevated NT-proBNP group （β=0.399,P 〈0.01）.Conclusions In this community based population,NT-proBNP elevation was common.In addition to female gender and older age,subclinical myocardial injury indicated by the hs-cTnT level was another important factor in NT-proBNP elevation.

Analyses of N‑Terminal Pro‑Brain Natriuretic Peptide,Cardiac Troponin T,and Creatine Kinase MB in Pericardial Fluid in Sudden Cardiac Death Caused by Ischemic Heart Disease

Background:Biochemical analyses of N‑terminal pro‑brain natriuretic peptide(NT‑proBNP),cardiac troponin T(cTnT),and creatine kinase MB(CK‑MB)have been reported to be valuable for the auxiliary diagnosis of sudden cardiac death(SCD)in previous forensic studies.Aims and Objectives:The present study aimed to evaluate the diagnostic efficiency of combined analyses of NT‑proBNP,cTnT and CK‑MB in the pericardial fluid for forensic diagnosis of SCD caused by ischemic heart disease.Materials and Methods:Levels of NT‑proBNP,cTnT,and CK‑MB in the pericardial fluid of 132 medicolegal autopsy cases were obtained through electrochemiluminescence method.Results:NT‑proBNP,cTnT,and CK‑MB levels were significantly elevated in SCD cases(P<0.05).Receiver‑operating characteristics(ROC)analysis showed that NT‑proBNP,cTnT,and CK‑MB have diagnostic value for the diagnosis of SCD:NT‑proBNP,cutoff value of 2236 pg/ml;cTnT,cutoff value of 199.51 ng/ml;CK‑MB:cutoff value of 2742.5 ng/ml,and the combined analyses of these three biomarkers have better diagnostic efficiency than each single biomarker alone.Moreover,the causes of SCD were sub‑divided into acute ischemic heart disease,acute myocardial infarction(AMI),and recurrent myocardial infarction subgroups for further analysis,which revealed that the ratio of cTnT/CK‑MB could be used to distinguish AMI with the cutoff value of 0.1085 estimated by ROC analysis.Conclusion:These observations suggested that the postmortem biochemical analyses of NT‑proBNP,cTnT,and CK‑MB in the pericardial fluid may assist to diagnose SCD in forensic practice,and the combined analyses of multiple biomarkers have better diagnostic efficiency than each single biomarker alone.On the basis of the postmortem biochemical analyses of NT‑proBNP,cTnT and CK‑MB,combining the ratio of cTnT/CK‑MB could be used to distinguish AMI.