Abstract 16680: Lipoprotein(a) and Progression Rate of Aortic Valve Stenosis - A Pooled-Analysis of Two Prospective Studies

Abstract

Listen

Translate article

BACKGROUND: Recent studies have reported a single nucleotide polymorphism (i.e. rs10455872) at the LPA gene locus, encoding the lipoprotein(a) [Lp(a)], is associated with the presence of aortic valve calcification and clinical aortic stenosis (AS). The objectives of this study were to examine the association of Lp(a) plasma levels and rs 10455872 with the progression rate of AS. METHODS: Lp(a) plasma levels were measured in 203 patients with AS included in the ASTRONOMER (NCT00800800) trial and 246 patients in the PROGRESSA study (NCT01679431). The polymorphism rs10455872 was genotyped in the PROGRESSA cohort. Hemodynamic progression rate of AS severity was assessed by measuring the annualized increase in peak aortic jet velocity (Vpeak) by Doppler-echocardiography. RESULTS: Twenty-seven (13%) patients of the ASTRONOMER trial and 47 (19%) of the PROGRESSA study had high Lp(a) plasma levels (i.e. >50mg/dL). Baseline AS severity was similar in patients with high vs. low Lp(a) levels (p>0.10). In the pooled-analysis of both cohorts (a total of 449 patients with mean follow-up: 3.0 ±1.4 yrs), AS progression rate was similar in patients with Lp(a)>50 mg/dL compared to those with Lp(a)≤50 mg/dL (annualized change in Vpeak: +0.17±0.21 vs. +0.17±0.21 m/s/yr; p=0.97). Stratified analyses by cohort provided consistent results (ASTRONOMER: +0.20±0.21 vs. +0.25±0.19 m/s/yr; p=0.20; and PROGRESSA: +0.12±0.21 vs. +0.14±0.20 m/s/yr; p=0.46). In the PROGRESSA study, 38 (16%) patients carried at least one rs10455872 risk allele. Carriers of the risk allele had higher Lp(a) levels (58±24 vs. 20±38 mg/dL; p<0.0001). Baseline AS severity was similar in carriers and non-carriers whereas there was a borderline significant association for lower AS progression rate in carriers compared to non-carriers (+0.07±0.17 vs. +0.15±0.21 m/s/yr; p=0.05). Similar results were obtained for baseline and annualized progression rate assessed by aortic valve area. CONCLUSION: This prospective study shows that neither LPA gene variant nor Lp(a) plasma levels are associated with faster AS progression rate. Our findings do not support the notion that Lp(a) levels are related to AS progression rate in patients with AS.