Background:

Troponin measurements are routinely used in patients presenting with an acute coronary syndrome (ACS). However, information about the association of high-sensitivity Troponin T and I (hsTnT/I) with angiographical severity of coronary artery disease (CAD) remains sparse and studies comparing different hsTnT/I assays are lacking. We therefore aimed to investigate the association of hsTnT/I with CAD severity in patients presenting with chronic coronary syndromes undergoing invasive coronary angiography.

Methods:

Overall, 2,881 patients undergoing coronary angiography were included in the observational Hamburg INTERCATH study between 2015 and 2020. hsTnT/I blood levels were available for both, hsTnT and hsTnI, in the first 2,209 participants. After exclusion of patients with ACS, chronic kidney disease (eGFR <60 ml/min) and heart transplant recipients, 1,246 participants remained for current analyses. Disease severity was graded according to the CAD classification (no CAD, coronary sclerosis, 1-, 2-, 3-vessel disease), Gensini, and SYNTAX scores. Troponin was quantified in baseline samples using Elecsys hsTnT (Roche), STAT hsTnI (Abbott) and Sgx Clarity hsTnI (Singulex). Ordinal logistic regression for the severity of CAD adjusted by age, gender, arterial hypertension, hyperlipoproteinemia, smoking, diabetes mellitus, body mass index, and eGFR was performed with each troponin assay as an independent variable.

Results:

Mean age was 66.5±10.8 years (25.3% female), 78.4% participants were diagnosed with CAD (mean number of diseased vessels 1.9±1.3, SYNTAX score 7.7±9.9, Gensini score 20.7±30.2). Median hsTnT/I blood levels were 13.0 (IQR 8.0, 23.0) ng/L, 6.6 (IQR 3.1, 16.9) ng/L and 3.6 (IQR 1.9, 9.3) ng/L for Roche-hsTnT, Abbott-hsTnI and Singulex-hsTnI, respectively. hsTnT/I blood levels revealed a stepwise increase across the applied categories of CAD severity and were highest in patients with most severe CAD. Roche-hsTnT was 26.0 (IQR 12.0, 56.7) ng/L in patients with a SYNTAX Score ≥33 compared to 11.0 (IQR 7.0, 19.0) ng/L in patients without CAD (Abbott-hsTnI: 11.3, IQR 4.5, 97.7 vs. 4.6, IQR 2.4, 11.4; Singulex-hsTnI: 8.1, IQR 2.4, 39.9 vs. 2.8, IQR 1.5, 6.4). For the association of Roche-hsTnT, Abbott-hsTnI, and Singulex-hsTnI with the CAD classification, odds ratios per standard deviation (OR) were 1.22 (95% confidence interval [CI] 1.08-1.37), 1.31 (CI 1.16-1.47), and 1.27 (CI 1.12-1.44), respectively. The associations for the investigated assays with SYNTAX and Gensini scores, respectively, were OR 1.25, CI 1.09-1.43 and OR 1.23, CI 1.09-1.38 (Roche-hsTnT), OR 1.33, CI 1.15-1.52 and OR 1.30, CI 1.15-1.47 (Abbott-hsTnI), OR 1.31, CI 1.14-1.51 and OR 1.31, CI 1.16-1.48 (Singulex-hsTnI) (Figure 1).

Conclusion:

Baseline hsTnT and hsTnI blood levels were independently associated with the severity of CAD in patients presenting with chronic coronary syndrome.