Aortic and mitral valvular calcification in patients undergoing hemodialysis for 10 years or more and their prognosis

Valvular disease in hemodialysis (HD) patients occurs at a younger age and progresses faster compared with valvular changes due to aging in the general population [1]. The following can be involved in the mechanism of valvular calcification: parathyroid abnormality, aging, long-term HD, and calcium deposits in valves due to calciumbased drug or phosphate binder [2]. Valvular calcification can develop due to hypertension, diabetes mellitus (DM), dyslipidemia, renal anemia, blood access, and infective endocarditis [3]. In this study, we examined aortic valvular calcification (AVC) and mitral valvular calcification (MVC) in patients undergoing HD for 10 years or more. Computed tomography (CT) and echocardiography were used to detect calcification. Comparison was made between valvular calcification and risk factors for arteriosclerosis. In addition, prognosis of valvular disease was examined. The subjectswere 41patients undergoingoutpatientHD for 10 years ormore. Theywere 29men and 12women (mean age: 60±8 years and meandurationofHD: 20±7 years). Theunderlyingdiseasewas chronic glomerulonephritis (CGN) in 28 patients (mean duration of hemodialysis: 23±7 years), DM in 10 patients (12±1 years), and polycystic kidney disease in 3 patients (22±1 years). Non-contrast enhanced cardiac CT was performed with a 0.5-second scan time and 1 cm scan width to examine the presence or absence of AVC and MVC. Visual assessmentwasperformed to evaluate the density of calcification. In the same period, the followingwasmeasured just before HD in the two-day break between HD sessions: total cholesterol, high density lipoprotein cholesterol (HDLC), triglyceride, postprandial glucose, hemoglobin A1c, calcium (Ca), phosphorus (P), Ca-P product, and parathyroid hormone. Echocardiography was also performed. All numerical data were expressed as means±standard deviation. Comparison of measurements between groups was performed using Student's unpaired t test. A p-value of less than 0.05 was defined to be statistically significant. Table 1 shows patient characteristics by underlying disease. AVCwas difficult to differentiate from aortic calcification and MVC from left circumflex artery calcification. In both AVC and MVC, the motion of the heart caused plus and minus density artifacts. Thus, the apparent density of calcification differed from the actual density, and determination of severity of valvular calcificationwas difficult using CT. Therefore, accurate comparison could not be performed between the results of blood tests and the degree of calcification. CTexamination revealed AVC in 38 of 41 patients, andMVCwas seen in all patients.When the density was examined in each patient, the visually assessed density tended to International Journal of Cardiology 164 (2013) 123–128