The management of serum potassium in maintenance hemodialysis（MHD ）patients is one of the hot topics at present. In order to control hyperkalemia in dialysis patients, the use of hypokalemic dialysate is the most important measure to reduce potassium. This measure effectively reduces serum potassium, but increases the risk of hypokalemia after dialysis, which increases the risk of all-cause death in patients. Hyperkalemia and hypokalemia during and at the end of dialysis are important factors for arrhythmia and death in MHD patients. Due to the intermittent nature of hemodialysis treatment, MHD patients often experience frequent fluctuations in serum potassium, which is a potential risk factor for poor prognosis of MHD patients. Serum potassium variability can better reflect the potassium homeostasis in MHD patients. In addition to hyperkalemia and hypokalemia, serum potassium variability is a potential risk factor affecting the prognosis of MHD patients. At present, there are few studies on the effect of improving serum potassium variability on cardiovascular complications, especially multi-center randomized controlled trials. In this study, sodium zirconium cyclosilicate was used to control hyperkalemia before dialysis and increase potassium concentration in dialysate, so as to reduce the risk of hypokalemia after dialysis, and to verify whether improving serum potassium variability can reduce myocardial injury in hemodialysis patients.

Inclusion Criteria:

1. Age 18-75 years old;
2. Maintenance hemodialysis ≥3 months;
3. Serum potassium ≥5.0mmol/L and ≤8mmol/L before dialysis;
4. Have independent ability;
5. Complete clinical baseline data.

Exclusion Criteria:

1. Complicated with congenital heart disease, myocardial infarction and other heart diseases that may lead to cardiac dysfunction;
2. Combined with other serious diseases, such as immune diseases, severe liver and kidney dysfunction;
3. Unable to cooperate with the researcher due to mental reasons;
4. If the duration of dialysis is less than 4 hours, severe infection;
5. Patients with malignant tumors or major mental disorders;

6, except primary cardiomyopathy;

7. Severe constipation, intestinal obstruction, etc.

8. other investigators considered that enrollment was not recommended.