Objective:To explore the prognostic value of the serum concentration of human soluble stromelysin-2(sST2)combined with ultrasonic left ventricular diastolic function parameters for elderly patients with septic shock.Methods:This prospective study involved 150 elderly patients with septic shock admitted to the intensive care unit(ICU)of the First Hospital of Jiaxing between May 2019 and May 2022.Data on the following parameters were recorded on days 1, 3, 5, and 7 in the ICU: sST2 concentration, mitral early-diastolic inflow peak velocity(E), mitral late-diastolic inflow peak velocity(A), E/A ratio, early diastolic mitral annular velocity(e'), and E/e' ratio.According to the 28-day prognostic outcome obtained during follow-up, patients were divided into a survival group and a death group to compare differences in values of the above parameters between the two groups and at different time points.Logistic regression was used to analyze independent risk factors for 28-day mortality.The receiver operating characteristic(ROC)curve was used to analyze the predictive value for 28-day mortality, and further risk stratification was performed according to optimal cut-off values to compare differences in 28-day mortality under different risk stratification methods.The Kaplan-Meier survival curve was used to compare 28-day cumulative survival under different risk stratification methods and analyze the predictive value of the combination of the parameters for 28-day mortality.Results:On day 5 following ICU admission, e' was lower and E/e' and sST2 were higher in the death group than in the survival group.Univariate and multivariate Logistic regression analysis suggested that sST2(odds ratio: 1.010, P<0.001)was an independent risk factor for 28-day mortality in elderly patients with septic shock.sST2 had a sensitivity of 50.2%, a specificity of 79.1%, and an area under the curve of 0.660 for predicting 28-day mortality in patients with septic shock.The sST2 concentration was 89.3 μg/L on day 5 after ICU admission, which was the clinical cutoff point for predicting 28-day mortality.Based on the risk stratification of sST2 levels, the 28-day mortality rate was higher in the sST2>89.3 μg/L group than in the sST2≤89.3 μg/L group.Kaplan-Meier survival analysis showed that the 28-day cumulative survival rate was significantly lower in the sST2>89.3 μg/L group than in the sST2≤89.3 μg/L group(44.0% vs.66.7%, log-rank test: χ2=9.101, P=0.003).The receiver operating characteristic curve showed that the combination of sST2, e', and E/e' significantly improved the prediction efficiency of 28-day mortality in elderly patients with septic shock, with an area under the curve of 0.844, a sensitivity of 89.7%, and a specificity of 66.5%. Conclusions:sST2 is an independent risk factor for 28-day mortality in elderly patients with septic shock.When combined with e' and E/e', sST2 can more accurately evaluate the survival prognosis of these patients.