Cardiac troponin T and NT-proBNP as diagnostic and prognostic biomarkers of primary cardiac involvement and disease severity in systemic sclerosis: A prospective study

Objectives: The aim of our study was to define the role of high-sensitive cardiac troponin T (hs-cTnT) and NT-proBNP in identifying Systemic Sclerosis (SSc) patients with cardiac involvement and at higher risk of cardiac death. Methods: Plasma hs-cTnT and NT-proBNP concentrations were measured in 245 SSc-patients. Results: hs-cTnT and NT-proBNP levels were higher in SSc-patients than in healthy controls. Hs-cTnT levels were higher than 0.014 ng/ml in 32.3% SSc-patients, while NT-proBNP was above 125 pg/ml in 31.8% of them, irrespective of classical cardiovascular risk factor and of pulmonary arterial hypertension. Elevated hs-cTnT and NT-proBNP were associated with diffuse skin involvement and directly correlated with the skin score. Patients with increased cardiac markers presented a lower left-ventricular ejection fraction (LVEF) and a higher rate of right bundle branch block (RBBB) on electrocardiogram (ECG) compared to patients with normal cardiac enzymes. During the follow-up, 12 SSc-patients experience a disease-related death; 9 of these were directly related to cardiac involvement (sudden cardiac death or heart failure) and the majority of them occurred among patients with increase of at least one cardiac biomarker. Long-term survival was worse in patients with increase of both cardiac biomarkers. Conclusions: Evaluation of hs-cTnT and NT-proBNP levels may provide a tool to screen non-invasively SSc-patients for heart involvement. A higher incidence of impaired systolic function, ECG abnormalities and a poor outcome in SSc-patients with elevated cardiac enzymes suggests that they may be valuable screening biomarkers to detect a cardiac damage at early stages and to improve risk stratification.