Cardiovascular Disease (CVD) is the main complication and the most important cause of death in CKD patients. As the disease progresses, the incidence of cardiovascular disease in CKD patients gradually increases, especially in End-Stage Renal Disease (ESRD) patients receiving dialysis treatment, where the prevalence of cardiovascular disease reaches its highest level. Currently, there is a lack of a simple and reliable tool to assess the cardiac function status and predict the risk of cardiovascular events in patients on maintenance dialysis. The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a widely used patient-reported outcomes measurement tool for assessing health-related quality of life in heart failure patients. It has been shown that KCCQ scores not only reflect the underlying undiagnosed symptoms of heart failure in CKD patients, but also have a strong correlation with prognosis. However, there is currently insufficient clinical evidence to confirm the value of the KCCQ in patients on maintenance dialysis. Investigators will perform a prospective, single-center, observational study to collect the changing trend of KCCQ scores at baseline and during the observation periods in maintenance dialysis patients, to analyze the association between the scores and the occurrence of long-term cardiovascular events and all-cause mortality. The aim is to construct a predictive model of KCCQ scores to provide a reference basis for clinical management of this high-risk group, so as to optimize the diagnosis and treatment of heart failure in dialysis patients and improve their cardiovascular outcomes.