Cardiac biomarkers in systemic sclerosis: contribution of high-sensitivity cardiac troponin in addition to N-terminal pro-brain natriuretic peptide.

Abstract

To measure plasma concentrations of high-sensitivity cardiac troponin T (HS-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with systemic sclerosis (SSc; scleroderma) and age- and sex-matched healthy control subjects, and to examine the contribution of traditional cardiovascular risk factors and SSc features to the concentrations of these 2 cardiac biomarkers. Plasma HS-cTnT and NT-proBNP concentrations were measured using the electrochemiluminescence method and sandwich immunoassay, respectively. The study group comprised 161 unrelated patients with SSc and 213 matched control subjects. HS-cTnT and NT-proBNP plasma levels were significantly increased in SSc patients compared with controls (both P < 0.001). Similar results were observed in the subgroup of patients with SSc who had no cardiovascular risk factors (n = 72). Multivariate logistic regression analysis confirmed diabetes mellitus (P = 0.006), high blood pressure (P = 0.021), precapillary pulmonary hypertension (P = 0.039), and the diffuse cutaneous SSc (P = 0.004) as factors independently associated with an HS-cTnT level of >14 ng/liter. Increased NT-proBNP concentrations were associated only with the presence of precapillary pulmonary hypertension (P < 0.001). Normal concentrations of both HS-cTnT and NT-proBNP had a high negative predictive value for precapillary pulmonary hypertension (92%), and the combination of increased values of these 2 markers had the highest strength of association with precapillary pulmonary hypertension in logistic regression analysis. HS-cTnT and NT-proBNP concentrations are increased in patients with SSc, even in those who are free of cardiovascular risk factors. These easily obtained biomarkers may be useful for systematic evaluation and stratification of SSc patients, especially to identify those at risk of pulmonary hypertension.