Abstract 11155: Impact of Serum Calcium Levels on Mortality of Patients With Heart Failure and Chronic Kidney Disease

Abstract

Background: Chronic kidney disease-mineral and bone disorders (CKD-MBD) are associated with vascular calcification and abnormal electrolyte that lead to cardiovascular disease and mortality. CKD-MBD are identified by imbalances in serum calcium (Ca), phosphate, and parathyroid hormone (PTH). Although, the relation of phosphate and PTH to prognosis of HF patients has been reported, prognostic impact of Ca on patients with heart failure (HF) and CKD remains unclear. Methods and Results: Consecutive 191 patients admitted for HF and CKD (estimated GFR < 60 ml/min/1.73 m 2 ) were divided into 3 groups based on levels of corrected Ca: low Ca (Ca < 8.4 mg/dl, n = 32), normal Ca (8.4 ≤ Ca <10.0, n = 149), and high Ca (10.0 ≤ Ca, n = 10) groups. We compared echocardiographic findings and levels of hemoglobin, BNP, troponin T, CRP, estimated GFR, intact PTH, phosphate, zinc (Zn), and magnesium (Mg) among the three groups. Furthermore, we prospectively followed cardiac, non-cardiac, and all-cause mortality. The low Ca group, as compared to normal and high Ca groups, had lower levels of hemoglobin and Zn (hemoglobin: 11.2 vs. 12.4, 13.0 g/dl, P < 0.001; Zn: 58.1 vs. 70.1, 71.0 mg/dl, P = 0.003). Age, body mass index, BNP, troponin T, CRP, estimated GFR, intact PTH, phosphate, Mg, and left ventricular ejection fraction were similar among the three groups. Importantly, cardiac mortality (log-rank P = 0.003) and all-cause mortality (P < 0.001), but not non-cardiac mortality, were higher in low Ca group than in normal and high Ca groups in HF and CKD patients. In the multivariate Cox proportional hazard analyses, hypocalcemia was an independent predictor of cardiac (HR 2.34, P = 0.007) and all-cause mortality (HR 1.89, P = 0.027) in HF and CKD patients. Conclusions: Hypocalcemia was an independent predictor of cardiac and all-cause mortality in HF and CKD patients. Thus, taking appropriate management to control CKD-MBD balance may improve the prognosis of patients with HF and CKD.