15289-s-bos

76 | Chapter 5 The independent association of Lp(a) concentrations with AVC was further investigated using multivariate logistic regression analysis with increasing numbers of significant AVC predictors from the univariate analysis. All data were analyzed using IBM SPSS v 21.0 software. Results were considered statistically significant at p < 0.05. Results Characteristics of study population The general characteristics of the study population are presented in table 1. The population consisted of 81 men and 48 women. The median age was 51 years (IQR = 46- 59) (range from 40-69 years). The majority of patients (97.7%) was treated with statins. The median duration of statin-use was 7 years (IQR = 2-14) (range from 0-30 year). Data on calcification scores were available for all participants. A total of 50 patients (39.8%) had developed AVC, of which 3 (2.3%) patients had extensive calcification of more than 400 AU. Prevalence of CAC was 79.1%with 28 patients having developed extensive CAC. No bicuspid aortic valves were identified. Plasma Lp(a) concentration and apo(a) KIV isoforms The median plasma Lp(a) concentration was 26.7 mg/dL, ranging from 0.5 to 419.8 mg/ dL (IQR = 8.1-63.9 ). Plasma Lp(a) levels were significantly higher in patients with AVC than in those without (43.4(10.6-105.0) vs. 24.5(5.5-49.1) mg/dL, p = 0.02). Thirty six (27.9%) patients had one or two isoforms of LMW apo(a) and 90 (69.8%) patients had only HMW apo(a) isoforms. We were unable to measure the apo(a) KIV repeat number of the other 3 patients. Therefore, the frequency of the LMW apo(a) phenotypes in the population was 0.29. The frequency of LMW apo(a) phenotypes was not significantly different between patients with and without AVC (31% vs. 27%, p = 0.68). As expected, patients with LMW apo(a) phenotypes had higher plasma Lp(a) concentrations than those with HMWapo(a) (91.5(26.6-129.8) vs. 18.0(4.2-41.2) mg/dL, p < 0.001). In addition, the number of apo(a) KIV repeats was inversely correlated with Lp(a) concentrations (r = -0.57, p < 0.001). Lp(a) concentrations positively correlated with both the presence (r = 0.21, p = 0.02) and the severity (r = 0.19, p = 0.04) of AVC.