Abstract 15151: Impact of Plasma Lipoprotein(a) Level on the Progression of Aortic Stenosis - The PROGRESSA Study
BACKGROUND: A recent genome-wide association study reported that genetic variation at the LPA gene locus is associated with aortic valve calcification and incident clinical aortic stenosis (AS) by acting through lipoprotein(a) [Lp(a)] plasma levels. This novel finding suggests that plasma Lp(a) level could be directly implicated in the pathophysiological process leading to development and/or progression of AS. The aim of this study was to examine the potential association between plasma Lp(a) levels and: i) baseline severity and ii) progression rate of AS in a prospective cohort.
METHODS: 138 patients with AS were prospectively recruited in the PROGRESSA study and underwent a Doppler-echocardiography annually. AS severity was assessed by peak aortic jet velocity (Vpeak) and indexed aortic valve area (AVAi). Hemodynamic progression rate of AS was assessed by measuring the annualized increase in Vpeak and AVAi. Plasma Lp(a) level was log transformed to normalized distribution.
RESULTS: For the 138 patients, 27% were women and the mean age was 66 ±13 yrs. 73% of patients had hypertension, 67% dyslipidemia and 22% diabetes. At baseline, average Vpeak was 2.8±0.6 m/s and AVAi was 0.69±0.19 cm2/m2. The mean follow-up time was: 2.2 ±1.3 years. Lp(a) plasma level was correlated with baseline AS severity (Vpeak: r=0.17, p=0.04; AVAi: r=-0.20, p=0.02). After adjustment for age, gender, body mass index, hypertension, diabetes, LDL chol, and creatinine, plasma Lp(a) level remained independently associated with Vpeak (p=0.03) or AVAi (p=0.04). Further adjustment for statin therapy provided similar results (Vpeak: p=0.03; AVAi: p=0.03). In contrast, plasma Lp(a) plasma level was not significantly associated with the progression rate of AS severity (Vpeak: p=0.33; AVAi: p=0.31). Results were similar in men versus women as well as in different age groups and AS severity subsets.
CONCLUSION: This study shows that Lp(a) plasma level is significantly associated with baseline AS severity but not with the stenosis progression rate. These findings suggest that Lp(a) could be implicated in the initiation of calcific aortic valve disease but not in its progression. Hence, this study suggest that Lp(a) lowering therapy may not be efficient to delay AS progression.
- © 2013 by American Heart Association, Inc.