Objective To investigate the expression levels of heat shock protein 70(HSP70),osteopontin(OPN)and matrix metalloproteinase-9(MMP-9)in patients with valvular heart disease and their correlations with cardiac function.Methods A total of 168 patients with valvular heart dis-ease were selected as study group,while 100 healthy individuals who underwent physical examination during the same period served as healthy control group.Serum levels of HSP70,OPN and MMP-9 were measured and compared between the two groups.The 168 patients were further divided into grade Ⅱ group(n=68),grade Ⅲ group(n=57)and grade Ⅳ group(n=43)based on the classi-fication of cardiac function in patients with valvular heart disease.Serum levels of HSP70,OPN and MMP-9 were compared among different cardiac function grades.The correlations of serum levels of HSP70,OPN and MMP-9 with left ventricular ejection fraction(LVEF)were analyzed.Factors influ-encing cardiac function grading in patients with valvular heart disease were screened.Receiver operat-ing characteristic(ROC)curve analysis was used to evaluate the diagnostic efficacy of serum HSP70,OPN and MMP-9 for cardiac function grading in patients with valvular heart disease.Results Serum levels of HSP70,OPN and MMP-9 in the study group were significantly higher than those in the healthy control group(P＜0.05).Patients with multiple valve lesions had significantly higher serum levels of HSP70,OPN and MMP-9 compared to those with single valve lesions(P＜0.05).Serum levels of HSP70,OPN and MMP-9 in grade Ⅲ group and grade Ⅳ group were significantly higher than those in the grade Ⅱ group(P＜0.05);serum levels of HSP70,OPN and MMP-9 in the grade Ⅳgroup were significantly higher than those in the grade Ⅲ group(P＜0.05).Age,co-morbid dia-betes,disease classification,LVEF,HSP70,OPN and MMP-9 were identified as factors influencing cardiac function grading in patients with valvular heart disease(P＜0.05).Serum levels of HSP70,OPN and MMP-9 showed significant negative correlations with LVEF in patients with valvular heart disease(r=-0.611,-0.584,-0.624,P＜0.001).Combined diagnosis using serum HSP70,OPN and MMP-9 demonstrated superior diagnostic performance for cardiac function grading in pa-tients with valvular heart disease compared to individual markers(P＜0.05).Conclusion Serum levels of HSP70,OPN and MMP-9 are elevated in patients with valvular heart disease and increase with the progression of cardiac function grading.