Association of renal function with cardiac calcifications in older adults: the cardiovascular health study

Abstract

Background: Aortic valve sclerosis (AVS) and mitral annulus calcification (MAC) are highly prevalent in patients with end-stage renal disease. It is less well established whether milder kidney disease is associated with cardiac calcifications. We evaluated the relationships between renal function and MAC, aortic annular calcification (AAC) and AVS in the elderly.

Methods: From the Cardiovascular Health Study, a community-based cohort of ambulatory adults >or= age 65, a total of 3929 individuals (mean +/- SD age 74 +/- 5 years, 60% women) were evaluated with two-dimensional echocardiography. Renal function was assessed by means of creatinine-based estimated glomerular filtration rate (eGFR) and cystatin C.

Results: The prevalences of MAC and AAC were significantly higher in individuals with an eGFR < 45 mL/ min/1.73 m(2) (P < 0.01 for each), and cystatin C levels were significantly higher in individuals with MAC or AAC compared to individuals without these cardiac calcifications (P < 0.001 for each). After multivariate-adjustment, an eGFR <45 mL/min/1.73 m(2) was significantly associated with MAC [odds ratio 1.54 (95% CI 1.16-2.06), P = 0.003] and not associated with AAC [1.30 (0.97-1.74), P = 0.085] and AVS [1.15 (0.86-1.53), P = 0.355]. In addition, cystatin C levels were independently associated with MAC [odds ratio per SD 1.12 (1.05-1.21), P = 0.001] and not associated with AAC [1.07 (1.00-1.15), P = 0.054] and AVS [0.99 (0.93-1.06), P = 0.82]. Furthermore, the prevalence of multiple cardiac calcifications was higher in subjects with an eGFR < 45 mL/ min/1.73 m(2) and increased per quartile of cystatin C (P-values < 0.001). In addition, a significant trend was observed between an eGFR < 45 mL/min/1.73 m(2), increasing levels of cystatin C and the number of cardiac calcifications (P < 0.05).

Conclusions: In a community-based cohort of the elderly, moderate kidney disease as defined by an eGFR <45 mL/min/1.73m(2) and elevated levels of cystatin C was associated with prevalent MAC. In addition, a significant trend was observed between an eGFR <45 mL/min/1.73m(2), increasing levels of cystatin C and the number of cardiac calcifications. No associations were found between renal function and AAC or AVS.

Fig. 1

Percentage of subjects with none, one, two or three calcifications divided by categories of estimated glomerular filtration rate (eGFR) and quartiles of cystatin C. The prevalence of multiple cardiac calcifications was significant higher in subjects with an eGFR < 45 mL/min/1.73 m² and increased per quartile of cystatin C (both P-values < 0.001).