Abstract 3744: Cystatin C Is Associated With Mitral Annular Calcification In Elderly Adults: Results From The Cardiovascular Health Study
Background: A high prevalence of cardiac calcification has been observed in patients with end-stage kidney disease. The association between cardiac calcification and milder kidney disease has been less thoroughly characterized. We hypothesize that renal function is associated with mitral annular calcification (MAC), aortic annular calcification (AAC), and aortic valve sclerosis (AVS) in elderly.
Methods and results: From the Cardiovascular Health Study (CHS), we analyzed 3,929 subjects (74 ± 5 years, 60% women), who underwent a 2-dimensional echocardiogram between 1994 –1995. Measures of kidney function were creatinine-based estimated glomerular filtration rate (eGFR) as calculated by the MDRD equation and cystatin C levels. MAC was present in 42 %, AAC in 44%, and AVS in 54% of the subjects. Subjects with MAC, AAC, and AVS were significantly older and significantly more subjects used anti-hypertensive medication and had prevalent cardiovascular disease (p<0.05). Participants with MAC had higher blood pressure levels, LDL-cholesterol levels, waist to hip ratio, fibrinogen levels and a higher prevalence of diabetes (p<0.05). Participants with AVS were more likely to be male, had higher systolic blood pressure, lower HDL-cholesterol, and higher waist to hip ratio (p<0.05). Levels of cystatin C were significantly higher in subjects with MAC in comparison to subjects without MAC (mean ± standard deviation 1.12 ± 0.33 versus 1.07 ± 0.25 mg/L, p<0.001). We found similar differences in those with and without AAC (1.11 ± 0.33 versus 1.07 ± 0.25 mg/L, p<0.001). Using logistic regression analysis, there was a significant and graded association between quartiles of Cystatin C levels and MAC (adjusted odds ratios and 95% confidence intervals) 1.0, 1.09 (0.91 to 1.32), 1.16 (0.96 to 1.40), and 1.27 (1.04 to 1.55) for quartiles 1 through 4 respectively (p for trend 0.017). In addition, Cystatin C levels were significantly associated with AAC (p<0.001), but this association became non-significant after adjustment for co-variates (p<0.174). No associations were present between Cystatin C and aortic sclerosis, and eGFR and cardiac calcifications.
Conclusion: Cystatin C was significantly associated with the presence of MAC in a population-based cohort of elderly.