Valvular calcification and its relationship to atherosclerosis in chronic kidney disease

Abstract

Background and aim of the study: Cardiovascular calcification is a common complication in patients with chronic kidney disease (CKD). The study aim was to identify the characteristics and risk factors of valvular calcification, and its relationship to atherosclerosis, in CKD.

Methods: In this cross-sectional study, a total of 135 patients with CKD (mean age 52 +/- 11 years) included 58 pre-dialysis patients, 36 dialysis patients, and 41 renal transplant recipients. A control group of 58 subjects was also examined. The characteristics of valvular calcification were assessed using transthoracic echocardiography.

Results: The combined prevalences of mitral or aortic valve calcification were 31% in pre-dialysis patients, 50% in dialysis patients, 29% in renal transplant recipients, and 12% in controls (p = 0.001). The prevalences of mitral annular calcification were 17%, 31%, 27% and 2%, respectively (p = 0.001). In multivariate analysis, the risk factors for valvular calcification in CKD were age, duration of dialysis treatment and interleukin-6 level. Mitral annular calcification proved to be five-fold more common in diabetic patients than among non-diabetics. A close association between valvular calcification and patients with or without increased carotid intima-media thickness (44% versus 15%, p < 0.001), carotid plaque (77% versus 49%, p = 0.002), calcified carotid plaque (65% versus 26%, p = 0.001), coronary artery disease (40% versus 15%, p = 0.003) and peripheral arterial disease (46% versus 9%, p < 0.001) was found.

Conclusion: Valvular calcification is common in CKD, and is closely associated with findings of intimal arterial disease. The presence of inflammation and the duration of dialysis treatment contribute to this complication. Diabetes is also a prominent risk factor for mitral annular calcification in CKD.