Diagnostic utility of biomarkers of left ventricular stress in patients with aortic stenosis and preserved left ventricular ejection fraction

Introduction: Aortic stenosis (AS) is the most common acquired valvular heart disease. The early identification of patients with severe AS is crucial. NT-proBNP is a well-known biomarker of pressure overload, and its role in patients with AS has been demonstrated in previous studies. Another, less well-known biomarker of pressure overload is sST2 protein, and its role in AS is unclear. Aim: To evaluate the utility of sST2 protein, NT-proBNP and selected clinical parameters in the assessment of degenerative AS severity in a population with preserved left ventricular ejection fraction (LVEF). Material and methods: Sixty-nine consecutive patients (mean age: 68.42 12.58 years, 55.07% male) with symptomatic degenerative AS and preserved LVEF 45% were prospectively included. At enrollment complete transthoracic echocardiographic examination, ECG analysis, and standard laboratory tests including NT-proBNP were performed and blood samples for sST2 were obtained. Results: There were 43 (62.32%) patients with severe AS. The multivariate stepwise linear regression models revealed that only systolic blood pressure (SBP), Sokolow-Lyon index and left ventricular end-diastolic diameter (LVEDD) were independently associated with severe AS. Spearman correlation coefficients analysis showed no correlations between sST2 levels and a mild to moderate correlation between NT-proBNP concentration and parameters of AS severity. However, levels of NT-proBNP (p = 0.1857) and sST2 (p = 0.7851) did not differentiate patients according to severity of AS. Conclusions: In the study population with degenerative AS and preserved LVEF neither the NT-proBNP nor sST2 concentrations can be used to differentiate patients according to the severity of AS.