PURPOSE: Heart failure with preserved ejection fraction (HFpEF) affects half of all heart failure patients with an increasing prevalence. The accurate diagnostic of HFpEF is based on a complex echocardiographic algorithm. Novel biomarkers, such as ST2, might improve diagnostic capacity in heart failure patients. Therefore, this study aims to evaluate the association between ST2 levels and left ventricular diastolic dysfunction assessed by echocardiography.

METHODS: Patients undergoing routine echocardiography were prospectively enrolled in the present monocentric study. Patients with left ventricular dysfunction (LVEF <50 %), right ventricular dysfunction (TAPSE < 17 mm) or moderate to severe valvular heart diseases were excluded. Blood samples for measurements of ST2 and NT-proBNP were collected at the day of echocardiographic examination. Subgroups based on HFpEF grades were defined (0: no diastolic dysfunction (n=14); I: mild diastolic dysfunction (n=14); II: moderate diastolic dysfunction (n=29); III: severe diastolic dysfunction (n=11)).

RESULTS: A total of 68 patients were included. Regarding the distribution of biomarkers only levels of NT-proBNP increased significantly alongside decreasing grades of HFpEF. In contrast, ST2 did not (NT-proBNP: p=0.009; ST2: p=0.18). Furthermore ST2 did not correlate significantly with E/A (p=0.827) or E/E’ (p=0.23). In multivariable linear regression models adjusted for age, sex, creatinine, NT-proBNP, arterial hypertension, coronary artery disease and HFpEF, HFpEF was not significantly associated with ST2 (HFpEF: Beta 0.193, T 1.499, p=0.139). Furthermore, only ST2 was not able to discriminate patients with severe diastolic dysfunction, while NT-proBNP was (ST2: AUC=0.65, p=0.117; NT-proBNP: AUC=0.798, p=0.002). In multivariable logistic regression models ST2 and not NT-proBNP were not associated significantly with severe HFpEF grade III (ST2: OR=1,028; p=0.102; NT-proBNP: OR=1.000, p=0.416) after adjusting with age, sex and creatinine.

CONCLUSIONS: Compared to the known and valid heart failure biomarker NT-proBNP, this study demonstrates that ST2 is not able to reflect diastolic dysfunction assessed by echocardiography. In contrast, regarding previous studies, ST2 showed valuable results in detecting heart failure with reduced ejection fraction.