Prognostic Value of Circulating sST2 for the Prediction of Mortality in Patients With Cardiac Light-Chain Amyloidosis

Aims: Systemic light-chain (AL) amyloidosis is a multisystemic disorder leading to multiple organ dysfunction and mortality that is often caused by cardiac involvement. Soluble suppression of tumorigenicity 2 (sST2) is a novel biomarker identified for risk stratification of heart disease. The aim of this study was to investigate the value of circulating sST2 levels in prognosis and mortality risk assessments for the AL amyloidosis population. Methods and Results: A total of 56 patients diagnosed with AL amyloidosis were enrolled in Peking Union Medical College Hospital (PUMCH) from January 2015 to May 2018. The relationships between the clinical parameters and overall survival (OS) and risk factors for disease progression were assessed. Additionally, receiver operating characteristic (ROC) curves, Kaplan–Meier analysis, and Cox hazard models were performed to explore the predictive value of sST2 in mortality rates. We found that the median OS of all patients was 7.3 [interquartile range (IQR) 4.4, 15.9] months. The median baseline sST2 level was 12.2 (IQR 5.1, 31.1) ng/ml, and the sST2 high group had more severe patients with a higher Mayo stage. In the ROC analysis, the area under the curve (AUC) was 0.728 [95% confidence interval (CI) 0.603–0.853] for sST2 to predict the outcomes of AL amyloidosis patients, and the optimal cutoff value was 12.34 ng/ml (sensitivity 80.2%, specificity 61.1%). Moreover, in multivariate Cox proportional hazards regression analysis, sST2 acted as an independent predictor of poor functional outcome in patients with AL amyloidosis. Conclusion: In AL amyloidosis patients, sST2 was a strong and independent prognostic biomarker for all-cause mortality, providing complementary prognostic information of a novel scoring system for risk stratification.