Influencing factors of cardiac valve calcification (CVC) in patients with chronic kidney disease and the impact of CVC on long-term prognosis: a single-center retrospective study

OBJECTIVE: To investigate the effect of cardiac valve calcification (CVC) on the prognosis of patients with chronic kidney disease (CKD). METHODS: A total of 343 CKD patients were retrospectively analyzed, and divided into two groups according to the presence or absence of cardiac valve calcification. All patients were followed until death, loss to follow-up, or the end point of the study (December 2021). RESULTS: The incidence of CVC among the 343 CKD patients was 29.7%, including 21 cases of mitral valve calcification, 63 cases of aortic valve calcification, and 18 cases of mitral valve combined with aortic valve calcification. The incidence of CVC in CKD stages 1–2 was 0.3%, 5.2% in CKD stages 3–4, and 24.2% in CKD stage 5 (P < 0.05). Advanced age, higher serum albumin, higher cystatin C and lower uric acid levels were all associated with a higher risk of CVC. After six years of follow-up, 77 patients (22.4%) died. The causes of death were cardiovascular and cerebrovascular diseases in 36 cases (46.7%), infection in 29 cases (37.7%), gastrointestinal bleeding in nine cases (11.7%), and “other” in the remaining three cases (3.9%). A Kaplan Meier survival analysis showed that the overall survival rate of patients with CVC was lower than that of patients without CVC. CONCLUSION: The incidence of CVC, mainly aortic calcification, is high in patients with CKD. Advanced age, higher serum albumin and higher cystatin C levels were associated with a higher risk of CVC. Hyperuricemia was associated with a lower risk of CVC. The overall survival rate of patients with CVC was lower than that of patients without CVC.