CLINICAL USE OF THE NEW BIOMARKER ST2 IN PATIENTS WITH CHRONIC HEART FAILURE OF ISCHEMIC GENESIS: AN EXERCISE TEST
Aim. To study the role of soluble stimulating growth factor expressed by gene 2 (sST2), at rest and after exercise at the end of six-minute walk distance (6MWD) in predicting the development of adverse cardiovascular events (CVA) in patients with coronary artery disease with chronic heart failure (CHF) for 12 months of prospective observation. Material and methods. We included 35 patients with CHF of ischemic genesis (32 men) with 44 left ventricular ejection fraction [35; 52]% (average age 62 [57; 67] years). The concentration of sST2 in serum was determined by enzyme immunoassay prior to and immediately after completion of 6MWD. Results. After 12 months of prospective observation, patients were divided into 2 groups depending on the CHF genesis. Group 1 (n=15) included patients with an unfavorable CHF course, group 2 (n=20) included patients without adverse CVA. In patients of group 1, the level of sST2 reached 39,68 [32,28; 52,32] ng/ml, which is 26,2% higher than (p=0,007) the similar parameter in patients of group 2 - 29,29 [26,34; 33,78] ng/ml. According to the ROC-analysis, the level of sST2 ≥33,14 ng/ml can be considered as a marker of the development of adverse CVA for 12 months of observations (sensitivity - 73,3%, specificity - 75,0%, area under the ROC curve - 0,77, p=0,002). After 6MWD patients with unfavorable CHF had a tendency (p=0,211) for an increase in sST2 level by 9,3% from 39,68 [32,28; 33,78] ng/ml to 43,75 [36,85; 54,80] ng/ml. In patients with a favorable course of CHF, the level of sST2 did not change, reaching 29,29 [26,34; 33,78] ng/ml and 29,43 [23,79; 34,79] ng/ml after 6MWD. According to the ROC-analysis, it was found that in patients with coronary artery disease and CHF, determining of sST2 concentration in the blood after 6MWD allowed to achieve higher levels of specificity and sensitivity of stratification risk method of adverse CVA - 86,7% and 85,0%, respectively (the area under the ROC curve is 0,86, p<0,0001). Conclusion. Thus, the level of sST2 can be considered as a noninvasive marker for predicting of unfavorable cardiovascular diseases in patients with CHF and intermediate/reduced left ventricular ejection fraction. Concentrations of sST2, determined after exercise, have a higher prognostic value for the stratification of the risk of an adverse course of CHF in this cohort of patients.