Supplementary Material for: Risk Factors Associated with Left-Sided Cardiac Valve Calcification: A Case Control Study

<b><i>Objectives:</i></b> To identify risk factors associated with cardiac valve calcification that is easily detectable through routine blood tests in patients who received valve replacement therapy. <b><i>Methods:</i></b> Four hundred patients with valvular heart disease who underwent valve replacement surgery between December 2009 and January 2013 were enrolled in this study. Of these, 77 had valve calcification; the other 323 did not. Multivariate logistic regression analysis was used to assess for risk factors associated with valve calcification. <b><i>Results:</i></b> In our study population, rheumatic valve lesions were the most common reason for valve replacement. Degenerative nonstenotic valve lesion was a protective factor and degenerative stenotic valve lesion was a strong risk factor for valve calcification. Serum levels of gamma-glutamyl transferase (GGT) of between 30 and 46 IU/l and >90 IU/l and total bilirubin (TBIL) of between 15 and 20 μmol/l were positively correlated with valve calcification. Meanwhile, serum calcium (Ca<sup>2+</sup>) levels of between 2.3 and 2.4 mmol/l were negatively correlated with rheumatic valve calcification. <b><i>Conclusions:</i></b> Degenerative stenotic lesion is a risk factor and degenerative nonstenotic lesion a protective factor for cardiac valve calcification. Serum GGT and TBIL levels are positively correlated and serum Ca<sup>2+</sup> levels negatively correlated with rheumatic cardiac valve calcification.