The usefulness of sST2 and galectin-3 as novel biomarkers for better risk stratification in hypertrophic cardiomyopathy.

Background: Estimation of sudden cardiac death (SCD) risk is an integral part of clinical management of patients with hypertrophic cardiomyopathy (HCM). Identification of novel biomarkers of this disease can provide additional criteria for SCD risk stratification. Soluble suppression of tumourigenicity (sST2) and galectin-3 (Gal-3) are useful biomarkers for prognosis of heart failure (HF). Both of them appear to mediate cardiac fibrosis - an important pathogenetic process in HCM. Data about sST2 and Gal-3 usefulness in patients with HCM are limited.

Aim: The aim of this study was to evaluate sST2 and Gal-3 as potential novel biomarkers for better risk stratification in hypertrophic cardiomyopathy.

Methods: Serum sST2 and serum Gal-3 levels were measured in 57 patients with HCM and in 18 healthy controls. The patients with HCM underwent routine evaluation including medical history, physical examination, blood tests (including N-terminal pro-B-type natriuretic peptide [NT-proBNP] and high-sensitivity cardiac troponin T [hs-cTnT] measurements), 12-lead electrocardiography (ECG), 48-h Holter monitoring and two-dimensional (2D) echocardiography with the assessment of the maximal left ventricular wall thickness, left atrial diameter, maximal left ventricular outflow tract gradient, and left ventricular ejection fraction. Risk of SCD at five years according to HCM SCD-risk calculator was evaluated. The control group underwent ECG, 2D echocardiography, and NT-proBNP measurements to exclude asymptomatic heart disease.

Results: Concentrations of sST2 and Gal-3 were significantly higher in patients with HCM than in controls (14.9 ± 5.8 ng/mL vs. 11.7 ± 3.3 ng/mL, p = 0.03 and 8.4 ng/mL [6.8-10.0] vs. 6.2 ng/mL [5.8-7.7], p = 0.005, respectively). Levels of sST2 and Gal-3 were considerably different in the New York Heart Association (NYHA) groups (p = 0.008, p = 0.009, respectively). Patients who presented non-sustained ventricular tachycardia (nsVT) on 48-h Holter monitoring had higher levels of sST2 (19.1 ng/mL [12.2-24.2] vs. 13.2 ng/mL [10.0-17.1], p = 0.02). There were no significant relationships between sST2 and Gal-3 levels and HCM SCD-risk, history of syncope presence, family history of SCD, and echocardio-graphic parameters.

Conclusions: Gal-3 levels and sST2 levels were higher in patients with HCM than in the control group. There were significant differences in Gal-3 levels between NYHA classes, but no correlations between Gal-3 levels and other parameters were found. Apart from differences in sST2 levels between NYHA classes, we demonstrated higher levels of sST2 in patients with nsVT. These findings suggest that sST2 may be useful as an additional biomarker for better risk stratification in hypertrophic cardiomyopathy.