Clin Res Cardiol (2022).

Super sensitivity cardiac Troponin I compared to high sensitivity cardiac Troponin I to predict risk in patients with suspected chronic coronary syndrome
K. Imelmann1, B. von Jeinsen2, D. Grün3, J. S. Wolter2, S. Kriechbaum2, O. Dörr4, H. Nef4, C. W. Hamm4, C. Liebetrau5, T. Keller6
1Kardiologie und Angiologie, Justus-Liebig-Universität Giessen, Gießen; 2Abteilung für Kardiologie, Kerckhoff Klinik GmbH, Bad Nauheim; 3Medizinische Klinik I, Innere Medizin / Kardiologie, Justus-Liebig-Universität Giessen, Gießen; 4Medizinische Klinik I - Kardiologie und Angiologie, Universitätsklinikum Gießen und Marburg GmbH, Gießen; 5CCB am AGAPLESION BETHANIEN KRANKENHAUS, Frankfurt am Main; 6Franz-Groedel-Institut (FGI), Justus-Liebig-Universität Giessen, Bad Nauheim;

Background and Aim:
High sensitivity cardiac Troponin I (hs-cTnI) is a well known risk predictor in patients with coronary artery disease as well as in the general population. Lately, super sensitivity cardiac Troponin I (ss-cTnI) assays have been established. The aim of the present investigation was to compare the predictive value of ss-cTnI with a hs-cTnI assay in patients with suspected chronic coronary syndrome. 

We investigated 1367 patients (mean age 68.9 years, n=430 (31.5%) females) with suspected chronic coronary syndrome, who were enrolled in a multi-center, prospective biomarker registry. Patients were enrolled at the Kerckhoff Heart and Thorax Center in Bad Nauheim and the University Hospital of the Justus-Liebig-University in Gießen. Follow-up data was available in 1322 patients (96.7%). The primary endpoint overall mortality was reached in n=377 patients. Ss-cTnI and hs-cTnI were measured at baseline. To compare the predictive value of hs-cTnI and ss-cTnI regarding the primary endpoint of death, we performed a receiver operating characteristics (ROC) analyses in the overall cohort and additionally in patients with normal troponin values according to the hs-cTnI assay (below the sex-specific 99th percentile; female: 15.6 ng/L, male: 34.2 ng/L).

In the overall cohort, patients with higher ss-cTnI were older (p<0.001), had more renal failure (p <0.001), had a higher rate of coronary artery disease (p<0.001), higher HbA1c-values (p=0.001), a higher rate of arterial hypertension (p<0.001) and diabetes (p=0.006) and mortality was documented more frequently (p<0.001). The ROC analysis in the overall cohort showed an area under the curve (AUC) of 0.725 (0.695-0.754) for hs-cTnI with respect to the primary endpoint of death and a slightly higher AUC of 0.743 (0.716-0.770) for ss-cTnI (pAUCdiff=0.238). In the subcohort of individuals with hs-cTnI in the normal range, ss-cTnI predicted mortality with an AUC of 0.731 (0.699-0.763) also slightly higher than hs-cTnI with an AUC of 0.720 (0.689-0.752) also without reaching a statistical significance (pAUCdiff =0.239).  

Higher troponin I levels measured with a high or a super sensitive assay are associated with a higher rate of cardiac risk factors and are associated with an unfavorable outcome. However, ss-cTnI was not superior compared to hs-cTnI predicting overall mortality.