Prognostic significance of NT-proBNP and sST2 in patients with heart failure with preserved and mildly reduced ejection fraction

Aim. To study the prognostic significance of NT-proBNP and.rowth stimulation expressed gene 2 (ST2) in patients with heart failure with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF). Material and methods. The study included 207 patients with NYHA class II-IV (111 men and 96 women) with mean age of 72,6 +/- 11,4 years. Depending on echocardiographic data, patients were divided into 3 groups: 1 - HFpEF (n=85), 2 - HFmrEF (n=50); 3 (comparison group) - HF with reduced EF (HFrEF) (n=72). All patients who signed the informed consent, along with the standard examination, underwent a quantitative determination of the serum biomarker levels (NT - proBNP and sST2) by enzyme immunoassay. Survival was assessed 12 months after the enrollment. Results. The initial values of NT-proBNP level in patients with HFmrEF were 691,9 [248; 1915,5] pg/ml and were significantly higher than in HFpEF - 445,8 [214,6; 945,7] pg/ml, but significantly lower than in HFrEF - 1131,4 [411,5; 3039,5] pg/ml, p<0,05. The sST2 values in group 1 (23,21 [12,17;48,7] ng/ml) and group 2 (27,11 [16,98;53,76] ng/ml) did not differ, but were significantly lower, than in patients with HFrEF (44,6 [21,1; 93,5] ng/ml). Within 12 months, 51 patients reached the primary endpoint. All-cause mortality in patients with HFpEF was 11,8%, in HFmrEF - 31,9% (p <0,05), and HFrEF - 36%. In patients who survived for 12 months, regardless of the initial EF, NT-proBNP and sST2 levels were significantly lower than those who died. In survivors with HFpEF, NT-proBNP (443 [154; 862.8] pg/ml) and sST2 (22,8 [12,3; 33,8] ng/ml) values were lower than in those who died (1143,2 [223,9;2021,9] pg/mL, p<0,05) and 26,8 [9,6;74,8] ng/mL, p>0,05). In patients with HFmrEF, NT-proBNP and sST2 values among survivors and deceased patients were 397,4 [128,9;1088,5] vs 1939,7 [441,9;2536] pg/ml (p=0,009) and 18,6 [ 14,9;30,27,1] vs 59,9 [53,76;84,4] ng/mL (p=0,002), respectively. There were no significant differences in NT-proBNP and sST2 values in patients with cardiac and non-cardiac death. sST2 in deceased patients with HFpEF (26,8 [9,6; 74,8] ng/mL) and HFmrEF (59,9 [53,76; 84,4] ng/mL) also had no significant differences (p >0,05). According to ROC analysis in patients with HF and EF >40%, NT-proBNP >746 pg/ml (AUG, 0,709; p=0,005) with sensitivity 62% and specificity 69% and sST2 >27,1 ng/ml (AUG, 0,742; p=0,03) with a sensitivity of 80% and a specificity of 75,8% are predictors of poor prognosis. Conclusion. NT-proBNP >746 pg/ml and sST2 >27,1 ng/ml should be considered as predictors of poor prognosis in HF patients with EF >40%.