Objective To investigate the expression of serum Sestrin2 and Toll-like receptor 7(TLR7)in patients with severe pneumonia and sepsis and their predictive value for heart failure.Methods A total of 86 patients with severe pneumonia and sepsis complicated with heart failure(complicated with heart failure group)and 86 patients with severe pneumonia and sepsis(uncomplicated with heart failure group)who were diagnosed and treated in Shanxi Provincial People's Hospital from February 2022 to May 2023 were studied.Another 86 patients who underwent health examinations were included as the control group.Enzyme linked immunosorbent assay(ELISA)method was applied to measure serum levels of Sestrin2 and TLR7.Color doppler echocardiography was applied to measure cardiac function related indicators:left ventricular ejection fraction(LVEF),left ventricular end diastolic diameter(LVEDD),and left ventricular end systolic diameter(LESD).The expression of Sestrin2 and TLR7 levels and cardiac function in three groups was analyzed.Pearson correlation was applied to analyze the relationship between serum levels of Sestrin2 and TLR7 and cardiac function related indicators in patients with heart failure.Receiver operating characteristic(ROC)curve was applied to analyze the predictive value of serum levels of Sestrin2 and TLR7 in patients with severe pneumonia and sepsis complicated with heart failure.Results The serum levels of Sestrin2(11.59±3.31 ng/ml,16.13±3.62 ng/ml),TLR7(48.93±9.52 ng/ml,61.74±10.11 ng/ml),and cardiac function related indicators[LVEDD(53.28±5.76 mm,62.54±6.11 mm)and LESD(38.16±4.38 mm,48.15±5.02 mm)]were higher in uncomplicated heart failure group and complicated heart failure group than those in control group(7.11±2.34 ng/ml,40.12±10.16 ng/ml,44.86±5.02 mm,29.02±4.07 mm),with significant differences(qSestrin2=13.241,26.659,qTLR7=8.224,20.182,qLVEDD=13.824,29.028,qLESD=18.805,39.359,all P＜0.05),and those values in complicated with heart failure group were higher than those in uncomplicated with heart failure group,with significant differences(q=13.418,11.985,15.203,20.554,all P＜0.05).The LVEF(55.43％±6.62％,41.67％±5.84％)index in uncomplicated heart failure group and complicated heart failure group was lower than that in control group(62.75％±7.16％),with significant differences(q=10.344,29.789,all P＜0.05),and the index in complicated with heart failure group was lower than that in uncomplicated with heart failure group,with significant difference(q=19.455,P＜0.05).Pearson correlation analysis showed that serum levels of Sestrin2 and TLR7 in patients with heart failure were negatively correlated with LVEF(r=-0.419,-0.467,all P＜0.05),and positively correlated with LVEDD and LESD(r=0.456,0.419;0.402,0.437,all P＜0.05).Sestrin2 was positively correlated with TLR7(r=0.641,P＜0.05).ROC curve results showed that the area under the curve(AUC)of serum Sestrin2 combined TLR7 for predicting heart failure in severe pneumonia sepsis patients was 0.940,with sensitivity of 74.9％and specificity of 73.3％.Conclusion The serum levels of Sestrin2 and TLR7 in patients with severe pneumonia and sepsis were elevated and may have good predictive value for patients with heart failure.