Heart valve calcification and calcium x phosphorus product in hemodialysis patients: analysis of optimum values for its prevention

BACKGROUND: Prevalence of valve calcification (VC) in end-stage renal disease (ESRD) patients is high and information regarding modifiable predictors is scarce. Our aim was to determine the prevalence of VC in our maintenance hemodialysis (HD) population, and the optimal Ca x P value that most accurately predicted the presence of VC after controlling for comorbidities. METHODS: This was a cross-sectional observational study of a cohort of 52 stable patients on maintenance HD for more than 12 months. Mean 12 months serum biochemical data (calcium, phosphorus, PTH, lipids) and M-mode 2D echocardiogram were used to evaluate the presence or absence of mitral and aortic VC and ventricular geometry. RESULTS: Twenty patients (38.4%) presented with VC. Patients with VC were more commonly diabetic and showed higher levels of serum phosphorus, Ca x P product, total and LDL cholesterol, and poor ventricular geometry, as compared to patients without VC. Moreover, they required higher doses of both CaCO3 and Al(OH)3. Logistic regression analysis showed that VC was independently influenced by age, Ca x P, and diabetes. ROC curves illustrated that a Ca x P>43 mg2/dL2 was the optimal value in terms of sensitivity and specificity for predicting the presence of VC in our patient population. CONCLUSION: These findings highlight the importance of applying more vigorous measures for Ca x P control.