Highly sensitive serum cardiac troponin T and cardiovascular events in patients with systemic lupus erythematosus (TROPOPLUS study)

OBJECTIVE: Identification of biological markers able to better stratify cardiovascular risks in SLE patients is needed. We aimed to determine whether serum cardiac troponin T (cTnT) levels measured with a highly sensitive assay [high sensitivity cTnT (HS-cTnT)] may predict cardiovascular events (CVEs) in SLE. METHOD: All SLE patients included between 2007 and 2010 in the randomized, double-blind, placebo-controlled, multicentre PLUS trial were screened. Patients with no past history of CVE at inclusion and a follow-up period of >20 months were analysed. HS-cTnT concentration was measured using the electrochemiluminescence method on serum collected at PLUS inclusion. The primary outcome was the incident CVE. Factors associated with the primary outcome were identified and multivariate analysis was performed. RESULTS: Overall, 442 SLE patients (of the 573 included in the PLUS study) were analysed for the primary outcome with a median follow up of 110 (interquartile range: 99-120) months. Among them, 29 (6.6%) experienced at least one CVE that occurred at a median of 67 (interquartile range: 31-91) months after inclusion. Six out of 29 patients had more than one CVE. In the multivariate analysis, dyslipidaemia, age and HS-cTnT were associated with the occurrence of CVE. Kaplan-Meier analysis showed that a concentration of HS-cTnT > 4.27 ng/l at inclusion increased by 2.7 [hazard ratio 2.7 (95% CI: 1.3, 5.6), P =0.0083] the risk of CVE in SLE. CONCLUSION: HS-cTnT measured in serum is the first identified biomarker independently associated with incident CVE in SLE patients.