Prognostic role of high-sensitivity cardiac troponin T in patients with cardiac sarcoidosis: insights from ILLUMINATE-CS

Aims: The prognostic role of high-sensitivity cardiac troponin T (hs-cTnT) as a biomarker in patients with cardiac sarcoidosis (CS) has yet to be fully determined, especially when compared with B-type natriuretic peptide (BNP).

Methods and results: In this post-hoc analysis of the ILLUMINATE-CS (ILLUstration of the Management and prognosIs of JapaNese pATiEnts with Cardiac Sarcoidosis), which is a multicentre retrospective observational study, we analysed 103 patients (62.2 ± 10.9 years old, 31.1% male) diagnosed as CS and with available data for hs-cTnT measured at the time of diagnosis. The primary outcome was the combined outcomes of all-cause death, fatal ventricular arrhythmia events and heart failure hospitalization. During a median follow-up period of 2.6 (inter-quartile range, 1.6-5.7) years, 24 primary outcomes were observed. Patients with a high hs-cTnT level, defined as a level above the median value (>0.016 ng/mL), were associated with a higher incidence of adverse events than those with a low hs-cTnT level (log-rank, P = 0.017). In Cox regression analysis, a high log-transformed hs-cTnT level and a high log-transformed BNP level were significant risk factors for primary outcome [hazard ratio (HR), 4.368 (95% confidence interval, CI, 1.032-18.480), P = 0.045. and HR, 3.127 (95% CI, 1.029-9.499), P = 0.044, respectively]. Patients with both high hs-cTnT and high BNP (>140 pg/mL: above the median value) levels had a 3.49 (95% CI, 1.23-9.88)-fold increased risk of the primary outcome compared with patients with both low hs-cTnT and low BNP levels.

Conclusions: In patients with CS, a high hs-cTnT level is a useful predictor of adverse events, and combined measurement of hs-cTnT and BNP further improves the prognostic value.