Lp(a) and Aortic Valve Calcification (FHLPA)

February 20, 2020 updated by: Patrick Couture, Laval University

Relationships Between Lipoprotein(a) Levels and Aortic Valve Calcification in Patients With Heterozygous Familial Hypercholesterolemia

Aortic valve stenosis (AVS), the most common form of valve disease in the western world, afflicts more than 1 million individuals in North America [1] and the burden of AVS is high and is expected to double within the next 50 years [2]. Medical therapy to prevent development or reduce progression of AVS is currently not available and the only effective treatment for AVS is aortic valve replacement, for which costs have been estimated up to 120,000$ [3,4]. Recently, we and others have identified rs10455872 at the LPA locus as a susceptibility single nucleotide polymorphism (SNP) for aortic valve calcification (AVC) and AVS [5,6] and rs10455872 is associated with elevated plasma lipoprotein (Lp)(a) levels [7]. Lp(a) is a LDL-like particle consisting of hepatically synthesized apolipoprotein B-100 that is noncovalently bound to the plasminogen-like glycoprotein apolipoprotein(a) [8]. Lp(a) promotes atherosclerotic stenosis, and possibly thrombosis, and has been hypothesized to contribute to wound healing, each of which could explain an association with AVS [9,10]. Lp(a) is relatively refractory to both lifestyle and drug intervention, with only nicotinic acid and monoclonal antibody inhibition of the proprotein convertase subtilisin/kexin type 9 that have showed reductions in Lp(a) levels [11,12]. However, the evidence that patients with AVS could be characterized by high Lp(a) levels is scarce. Glader et al. [13] showed that plasma levels of Lp(a) were almost 1.5-fold higher in 101 patients with AVS compared to matched controls, although this relationship did not reach statistical significance. Subsequent studies have also reported an association between elevated plasma Lp(a) levels and higher prevalence of AVS. More specifically, Kamstrup and colleagues [14] reported that elevated Lp(a) levels and corresponding genotypes were associated with increased risk of AVS in the general population with levels >90 mg/dL predicting a threefold increased risk. We have measured Lp(a) and oxidized phospholipids plasma levels in 220 patients with mild-to-moderate calcific AVS enrolled in the Aortic Stenosis Progression Observation: Measuring Effects of Rosuvastatin (ASTRONOMER) trial [15]. Results of this study suggest that high Lp(a) and oxidized phospholipids both predict calcific AVS progression, especially in younger patients with calcific AVS. We also found that statin therapy considerably increased both Lp(a) and oxidized phospholipids levels. Whether the fact that statins increase these risk factors for calcific AVS might explain at least to a certain extent why statins failed to promote calcific AVS regression or stabilization in at least four trials, including ASTRONOMER.

Familial hypercholesterolemia (FH) is an autosomal codominant single-gene disorder caused by mutations in the LDL receptor gene that disrupt normal clearance of LDL. Phenotypic features characteristic of the disease's heterozygous form are 2- to 3-fold raise in plasma LDL-cholesterol concentrations, tendinous xanthomatosis and premature atherosclerotic coronary artery disease. High Lp(a) levels have been shown to explain residual cardiovascular disease risk in FH [16,17]. Recent studies have demonstrated that FH heterozygotes have elevated AVC compared with non-FH subjects [18] and that Lp(a) levels were positively correlated with AVC in asymptomatic FH heterozygotes [19]. Vongpromek et al. [19] demonstrated that plasma Lp(a) concentration is a independent risk factor for AVC in a cohort of 129 asymptomatic heterozygous FH patients aged between 40 and 69 years. In this study, AVC was significantly associated with plasma Lp(a) level, age, body mass index, blood pressure, duration of statin use, cholesterol-year score and coronary artery calcification (CAC) score.

Study Overview

Status

Completed

Conditions

Heterozygous Familial Hypercholesterolemia

Study Type

Observational

Enrollment (Actual)

173

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Canada
- - Quebec, Canada, G1V 0A6
    - Institute of Nutrition and Functional Foods (INAF)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

primary care clinic

Description

Inclusion Criteria:

Men or women with heterozygous FH aged between 18 and 80 years
FH patient carrying a documented mutation in the LDL receptor gene
Subjects must be willing to give written informed consent and able to adhere to visit schedule

Exclusion Criteria:

Men or women < 18 or > 80 years
Non-FH subjects
History of alcohol or drug abuse within the past 2 years
Subjects who are in a situation or have any condition that, in the opinion of the investigator, may interfere with optimal participation in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Association between Lp(a) concentrations and aortic valve calcification Time Frame: Week 1	Week 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Laval University

Collaborators

Amgen

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 30, 2017

Primary Completion (Actual)

October 31, 2019

Study Completion (Actual)

February 19, 2020

Study Registration Dates

First Submitted

November 25, 2016

First Submitted That Met QC Criteria