Abstract: Ｏｂｊｅｃｔｉｖｅ：To analyze the clinical characteristics of maintenance hemodialysis （MHD） patients with high-flow arteriovenous fistulas，alongside the alterations in cardiac structure and function，to evaluate the influence of high-flow arteriovenous fistulas on mortality and cardiovascular events in MHD patients.
Ｍｅｔｈｏｄｏｌｏｇｙ：This study included patients undergoing hemodialysis at department of nephrology，the second affiliated hospital of Nanjing Medical University between March and May 2022. High-flow arteriovenous fistula was defined as fistula blood flow≥1 500 mL／min. Patients were divided into two groups，high-flow arteriovenous fistula，and non-high-flow arteriovenous fistula. The study analyzed baseline clinical characteristics and echocardiographic parameters of both groups，comparing the risk of cardiovascular events and mortality between the two groups.
Ｒｅｓｕｌｔｓ：The study included 341 MHD patients of which 210 （61.6%） were male. The mean age was 57.3 ± 12.3 years，and the median duration of dialysis was 78.7 （33.0～151.1） months. Among the patients，138 （40.5%） had an internal fistula blood flow of≥1 500 mL／min. In the high-flow arteriovenous fistula group，patients had a larger right atrial diameter （P=0.005），a larger main pulmonary artery diameter （P=0.007），a faster main pulmonary artery flow velocity （P=0.042），a higher proportion of heart valve calcification （P=0.028），and a higher ratio of arteriovenous fistula flow to cardiac output （P<0.001）. Other echocardiographic parameters did not differ between the two groups. The location of the fistula in the upper arm （OR=3.503，95%CI 1.702～7.209，P<0.001） and higher diastolic blood pressure at fistula creation （OR=1.045，95%CI 1.018～1.072，P<0.001） were independent factors influencing high-flow arteriovenous fistulas. The risk of cardiovascular events did not differ between the two groups （P=0.369），but the high-flow arteriovenous fistula group had a higher risk of mortality （P=0.013）.
Ｃｏｎｃｌｕｓｉｏｎ：MHD patients with high-flow arteriovenous fistulas did experience an increased risk of all-cause mortality. The independent factors associated with high-flow arteriovenous fistulas included the location of the fistula in the upper arm and higher diastolic blood pressure at fistula creation.

Key words: aintenance hemodialysis, arteriovenous fistula, high-flow arteriovenous fistula, echocardiography