THE CORRELATION BETWEEN HIGH-SENSITIVE CARDIAC TROPONIN T AND RISK STRATIFICATION BY GRACE SCORE IN PATIENTS WITH ACUTE CORONARY SYNDROME

Fazal Razi MD., Dr. Anoosha, Dr. Subhash and Wang Hai Rong* PhD

ABSTRACT

Background: Among all subtypes of coronary artery disease, the acute coronary syndrome (ACS) is one with high incidence, advanced severity and requires urgent medical intervention. Certain tools have been developed and used for the severity assessment and risk stratification of patients with ACS, such as the GRACE and SYNTAX and KILLIP etc. The hs-cTnT has been widely used in clinical practice for the diagnosis and prognosis prediction in ACS. The association between hs-cTnT and risk classification by GRACE has not been thoroughly investigated. Objective: To identify the association between hs-cTnT and risk classification by GRACE score and potential clinical utilization of serum hs-TnT in risk characterization for patients with acute coronary syndrome. Subjects and Methods: Medical records of 248 cases admitted to the Department of Cardiology, Zhongnan Hospital of Wuhan University were enrolled for the investigation of association between hs-cTnT and GRACE score. The baseline characteristics, medical history, laboratory tests, coronary angiography and all other required information for the analysis were extracted from the medical records. The subjects were divided as low vs. moderate/high risk group based on the GRACE score. Independent sample t test was used for the between group comparisons in terms of a continuous variable, and chi-square test was used for the between group comparisons in terms of a categorical variable. The association between hs-cTnT level and risk scores was analyzed using Spearman’s correlation analysis. The multivariable logistic regression analysis was used as multivariate analysis for addressing multiple correlations simultaneously and for adjustment. A P < 0.05 indicated statistical significance. The SPSS 20.0 was used for statistical analyses. Results: Significant difference was detected between the low score and moderate / high GRACE score groups in terms of hs-cTnT (6.57 ± 7.13 pg/mL vs. 78.10 ± 101.22 pg/mL, respectively in the low score and moderate / high score groups; P < 0.01), total bilirubin (15.69 ± 9.38 umol/L vs. 12.95 ± 7.99 umol/L, respectively in the low score and moderate / high score groups; P < 0.01), BNP (52.61 ± 64.11 pg/mL vs. 78.62 ± 110.77 pg/mL, respectively in the low score and moderate / high score groups; P < 0.05), and left ventricular ejection fraction (64.12 ± 5.13 % vs. 62.18 ± 6.64 %, respectively in the low score and moderate / high score groups; P < 0.05). A strong and significant positive correlation was found between serum hs-cTnT value and GRACE score (rho = 0.63, P < 0.01). The result of univariate linear regression was consistent with that of Spearman correlation analysis, indicating a significantly positive association between these two variables (beta = 0.17, P < 0.01). Moreover, the hs-cTnT was identified as the only independent significant predicting variable for GRACE score group (beta = 0.173, P < 0.05) Conclusions: In patients with acute coronary syndrome, a higher serum hs-cTnT level is significantly and positively correlated with a higher GRACE score, and patient subgroups with increased risk as well. It is suggested the potential clinical utilization of the hs-cTnT for the risk classification in patients with acute coronary syndrome. Further clinical investigation with larger sample size, prospective design and long-term follow-up is warranted to determine its effectiveness in classification and best categorizing strategy.

Keywords: Acute coronary syndrome, High-sensitive cardiac troponin T, GRACE scoring system.