Troponin I and echocardiography in patients with systemic sclerosis and matched population controls

Cardiac manifestations in systemic sclerosis (SSc) are associated with poor prognosis. Few studies have investigated cardiac troponins in SSc. We studied the relationships between echocardiographic abnormalities, cardiac biomarkers, and disease manifestations in a population-based cohort of patients with SSc and controls.

The study comprised 110 patients with SSc and 105 age- and sex-matched population-based controls. We examined ventricular function, heart valves, and estimated pulmonary arterial pressure (ePAP) by echocardiography in all participants. Disease characteristics, manifest ischaemic heart disease (IHD), and measurements of N-terminal prohormone brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin I (hs-cTnI) were tabulated.

NT-proBNP and hs-cTnI levels were higher in SSc patients than controls. Both NT-proBNP and hs-cTnI were associated with the presence of echocardiographic abnormalities. Forty-four SSc patients and 23 control subjects had abnormal echocardiograms (p = 0.002). As a group, SSc patients had lower (but normal) left ventricular ejection fraction (LVEF, p = 0.02), more regional hypokinesia (p = 0.02), and more valve regurgitations (p = 0.01) than controls. Thirteen patients and four controls had manifest IHD. Decreased right ventricular (RV) function (n = 7) and elevated ePAP (n = 15) were exclusively detected among SSc patients.

Both NTproBNP and hs-cTnI were associated with echocardiographic abnormalities, which were more prevalent in SSc patients than in controls. Our results thus suggest that hs-cTnI could be a potential cardiac biomarker in SSc. Low RV function and signs of pulmonary hypertension (PH) were uniquely found in the SSc group. SSc patients had more valve regurgitation than controls, an observation that warrants more clinical attention.