Troponin elevation independently associates with mortality in systemic sclerosis.

Abstract

Cardiac involvement is common in systemic sclerosis (SSc), and elevated troponin may be the only sign of ongoing myocardial disease. The objective was to determine whether the presence of elevated troponin associates with unique SSc characteristics and poor outcomes. This retrospective, cross-sectional study included patients in the Johns Hopkins Scleroderma Center Research Registry with any troponin measurement in the past 10 years. Clinical data were compared between those with elevated versus normal troponin. Survival analyses including Cox proportional hazards and regression analyses were performed. 272 patients with a troponin measurement were identified. 83 (31%) had elevated troponin. Compared to those with a normal troponin level, those with elevated troponin level were more likely to have the diffuse SSc subtype (p=0.005), lower left ventricular ejection fraction (57.7 ± 20% vs. 64.4 ± 17.4%, p=0.007), lower forced vital capacity percent predicted (61.1 ± 18.8% vs. 66.8 ± 20.4%, p=0.03), higher right ventricular systolic pressure (51.4 ± 20.9 vs. 43.4 ± 15.9 mmHg, p=0.001), higher Medsger muscle and heart severity scores (p≤0.001), and higher frequency of mortality (28% vs. 9.5%, p≤0.0001). Patients with elevated troponin also have a 2.16-fold (95% CI 1.01-4.63, p=0.046) increased risk of death compared to those without elevated troponin even after adjusting for age, sex, disease duration, and cardiopulmonary risk factors. Troponin may be a useful prognostic biomarker that may identify a subset of patients with heart disease that may warrant closer clinical investigation.