The Utility Of High-sensitivity Troponin T In Cardiovascular Diseases

Objective:We sought to determine the diagnostic performance of the new high-sensitivity cardiac troponin T (hs-cTnT) assay for early detection of non-ST-segment myocardial infartion (NSTEMI) in patients with acute coronary syndrome and compare it with the fourth generation cTnl assay and CK-MB, explore the sensitivity of serum troponin T(hs-cTnT)in unstable angina pectoris (UAP) in patients with clinical diagnosis,and coronary artery disease severity and the relationship between short-term prognostic value.Methods:1. Eighty-eight patients with diagnosis of suspected ACS without ST-segment elevation admitted to the study. All the patients from the onset of symptoms to admission are within6hours. Blood was tested with hs-TnT, cTnI and CK-MB at the same time. The diagnostic performance of them was assessed using ROC analysis. Based on the positive rate of the three cardiac markers, we inferred the sensitivity, specificity.2.152patients with TnI negative unstable angina pectoris(UAP)patients were selected,and serum hs-TnT was measured before coronary angiography,followed-up to90days.The main cardiovascular events(MACE)was recorded. Results:1.(1) The levels of the three markers in NSTEMI patients was obviously higher than UA patients(p<0.001),(2) The AUCs of hs-cTnT, cTnI and CK-MB were0.908^0.851、0.789, and the95%CI of the three markers were0.832～0.985,0.763～0.939,0.695～0.883,(3) Using the99th percentile cut point for14pg/ml, hs-cTnT had77.8%sensitivity,96.7%specificity,91.3%positive predictive value,96.8%negative predictive value for NSTEMI. Using the cut point for0.08ng/ml, cTnI had37.0%sensitivity,96.7%specificity,83.3%positive predictive value,77.6%negative predictive value for NSTEMI. Using the cut point for4ng/ml, CK-MB had25.9%sensitivity,93.4%specificity,63.6%positive predictive value,79.2%negative predictive value for NSTEMI.2. Serum hs-cTnT increased with the degree of coronary artery disease, the higher levels of serum hs-cTnT, more serious of coronary stenosis and vascular lesions. The levels of hs-cTnT were(12.0±11.2)pg/ml,(35.2±9.9)pg/ml in total occlusion groups respectively(P<0.05).The levels of hs-cTnT were (19.8±24.2)pg/ml and hs-cTnT(8.9±4.1)pg/ml in three lesions and normal risk group (P＜0.05); short-term cardiovascular events(heart sudden cardiac death, acute myocardial infarction, angina, readmission)in elevated serum hs-cTnT patients was higher than normal risk group(P＜0.001).Conclusion:1. A baseline sample of hs-cTnT allows an earlier prediction of NSTEMI than the less sensitive and precise fourth generation cTnl assay and CK-MB, which benefits the ruling in and early treatment of NSTEMI.2. In TnI negative UAP patients,serum hs-cTnT can detect more micro myocardial necrosis, while its serum levels may predict the severity of coronary stenosis;its rise may indicate short-term poor prognosis and the major cardiovascular increase, and may be used as an early risk stratification in UAP patients.