Lipoprotein(a) Testing Patterns in a Large Health System

doi:10.1016/j.amjcard.2021.05.018

The American Journal of Cardiology

Volume 153, 15 August 2021, Pages 43-50

https://doi.org/10.1016/j.amjcard.2021.05.018 Get rights and content

Lipoprotein (a) [Lp(a)] is associated with increased risk of atherosclerotic cardiovascular disease (ASCVD). As directed therapy for Lp(a) emerges, it is important to understand patterns of Lp(a) testing in routine clinical practice. We set out to characterize Lp(a) testing across a large academic health system. Using electronic health record (EHR) data from 2014 to 2019, we compared patients who underwent Lp(a) testing to date-matched peers who had low density lipoprotein (LDL-C) assessment alone. We analyzed ordering provider characteristics and rates of initiation of new lipid lowering therapy (LLT) within 12 months after testing. Of 1,296 adults with Lp(a) test results, 629 (48.5%) had prior history of ASCVD and 667 (51.4%) did not. Compared with those with LDL-C testing alone, individuals who underwent Lp(a) testing were more like to have a myocardial infarction or ischemic stroke at a young age and multiple prior cardiovascular events. Though the majority of Lp(a) tests were ordered in outpatient encounters, a higher proportion of Lp(a) tests compared with LDL-C tests were performed in the inpatient setting. Neurology and psychiatry were the most common specialty to order Lp(a) tests in our cohort. There was a significantly increased initiation of LLT after Lp(a) testing compared with LDL-C testing across all medication types. Consistent with guidelines, Lp(a) testing is used in those with early onset ASCVD, and among those with multiple cardiovascular events. Lp(a) testing is associated with more aggressive LLT in following year. Further research is needed to characterize Lp(a) testing across larger populations.

Section snippets

Methods

We extracted data from Duke University Healthcare System (DUHS) electronic health record (EHR). DUHS includes three hospitals and a network of outpatient clinics that have been integrated on an EHR system since 2014. This study received approval from the Duke Institutional Review Board.

Patients included in this study had at least one Lp(a) test between January 1, 2014 and October 10, 2019 (hereto referred to as Lp(a) cohort). A 4:1 date-matched control group included patients who had a

Results

Between January 1, 2014 and October 10, 2019, there were 2,088 Lp(a) lab tests results within DUHS on 1,926 individual patients. Among these, 1,296 patients had 2 prior encounters in the previous year to be included in the final analysis (Figure 1A). The LDL-C cohort was formed of 5,185 date-matched individuals (Figure 1B). The median Lp(a) value within the LP(a) cohort was 31mg/dL (Q1, Q3: 11, 78 mg/dL) (Figure 2).

Compared with date-matched controls with LDL-C but not Lp(a) testing,

Discussion

To our knowledge, this is the first study to characterize Lp(a) testing patterns in a real-world setting. We found that within a large academic health system, patients who underwent Lp(a) testing more frequently had a history of ASCVD, especially at younger ages, compared to those with LDL-C testing alone. Lp(a) was ordered by a variety of provider types, but the type with the highest proportion was neurology and psychiatry (a combined provider category within DUHS EHR). Those with Lp(a)

Disclosures

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Neha Pagidipati reports financial support was provided by Amgen, INC.

References (30)

P Willeit et al.
Baseline and on-statin treatment lipoprotein(a) levels for prediction of cardiovascular events: individual patient-data meta-analysis of statin outcome trials
Lancet
(2018)
S Erqou et al.
Apolipoprotein(a) isoforms and the risk of vascular disease: systematic review of 40 studies involving 58,000 participants
J Am Coll Cardiol
(2010)
V Schachinger et al.
Lipoprotein(a) selectively impairs receptor-mediated endothelial vasodilator function of the human coronary circulation
J Am Coll Cardiol
(1997)
JJ Albers et al.
Relationship of apolipoproteins A-1 and B, and lipoprotein (a) to cardiovascular outcomes: the AIM-HIGH trial (Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglyceride and Impact on Global Health Outcomes)
J Am Coll Cardiol
(2013)
DP Wilson et al.
Use of Lipoprotein(a) in clinical practice: A biomarker whose time has come. A scientific statement from the National Lipid Association
J Clin Lipidol
(2019)
WV Brown et al.
Management of Lp(a)†
J Clin Lipidol
(2010)
J Cegla et al.
HEART UK consensus statement on Lipoprotein(a): A call to action
Atherosclerosis
(2019)
S Tsimikas
A test in context: Lipoprotein(a): diagnosis, prognosis, controversies, and emerging therapies
J Am Coll Cardiol
(2017)
A Langsted et al.
Elevated Lipoprotein(a) and risk of ischemic stroke
J Am Coll Cardiol
(2019)
V Bittner et al.
Lp (a) and cardiovascular outcomes: an analysis from the ODYSSEY OUTCOMES trial
Atheroscler Suppl
(2018)

VA Bittner et al.

Effect of alirocumab on Lipoprotein(a) and cardiovascular risk after acute coronary syndrome

J Am Coll Cardiol

(2020)

A Sahebkar et al.

Effect of extended-release niacin on plasma lipoprotein (a) levels: a systematic review and meta-analysis of randomized placebo-controlled trials

Metabolism

(2016)

E Steyrer et al.

The role of lecithin: cholesterol acyltransferase for lipoprotein (a) assembly. Structural integrity of low density lipoproteins is a prerequisite for Lp(a) formation in human plasma

J Clin Invest

(1994)

R Clarke et al.

Genetic variants associated with Lp(a) lipoprotein level and coronary disease

N Engl J Med

(2009)

J Loscalzo et al.

Lipoprotein(a), fibrin binding, and plasminogen activation

Arteriosclerosis

(1990)

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Lipoprotein(a): An important piece of the ASCVD risk factor puzzle across diverse populations
2024, American Heart Journal Plus: Cardiology Research and Practice
Elevated lipoprotein(a) (Lp[a]) is an independent, genetic risk factor for atherosclerotic cardiovascular disease (ASCVD) that impacts ~1.4 billion people globally. Generally, Lp(a) levels remain stable over time; thus, most individuals need only undergo Lp(a) testing through a non-fasting blood draw once in their lifetime, unless elevated Lp(a) is identified. Despite the convenience of the test for clinicians and patients, routine Lp(a) testing has not been widely adopted. This review provides a guide to the benefits of Lp(a) testing and solutions for overcoming common barriers in practice, including access to testing and lack of awareness. Lp(a) testing provides the opportunity to reclassify ASCVD risk and drive intensive cardiovascular risk factor management in individuals with elevated Lp(a), and to identify patients potentially less likely to respond to statins. Moreover, cascade screening can help to identify elevated Lp(a) in relatives of individuals with a personal or family history of premature ASCVD. Overall, given the profound impact of elevated Lp(a) on cardiovascular risk, Lp(a) testing should be an essential component of risk assessment by primary and specialty care providers.
Prevalence of lipoprotein(a) measurement in patients with or at risk of cardiovascular disease
2023, Journal of Clinical Lipidology
Lipoprotein(a) [Lp(a)] is a genetically determined independent risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease. Despite recommendations from professional societies in the cardiovascular field, the awareness of elevated Lp(a) as a risk factor and screening for Lp(a) are suspected to be low.
We conducted a retrospective, observational case control study of patient charts from January 1, 2017 to June 19, 2022. The primary aims were 1) to describe the proportion of patients at the healthcare network's primary care and cardiology clinics that met Lp(a) screening criteria and were tested; and 2) to describe the proportion of patients throughout the entire healthcare network that had Lp(a) measured.
Of the 2,412,020 patient charts in the health network, only 5,942 (0.25 %) had Lp(a) measured. Of the 84,581 patients in primary care or cardiology clinics who met screening criteria, only 1,311 (1.55 %) had Lp(a) measured. Patients with Lp(a) measured were more likely to be younger, non-Hispanic/Latinx, had a lipid panel measured, a cardiac computed tomography (CT) imaging study, and higher low-density lipoprotein-cholesterol. Patients with ASCVD, heart failure, ischemic heart disease, aortic stenosis, peripheral vascular disease, or a stroke did not feature highly among patients who received Lp(a) testing. Having an abnormal or risk-enhancing Lp(a) level was associated with being female and/or being Black/African American.
Despite increased awareness of Lp(a) and its contribution to cardiovascular disease there exists a paucity of testing. Increased Lp(a) testing can identify patients who have an increased cardiovascular risk underestimated by other metrics.
Frequency of lipoprotein(a) measurements in patients with or at risk of cardiovascular disease
2023, Journal of Clinical Lipidology
Knowledge of lipoprotein(a) measurement in community practice is limited. The objective of this study is to evaluate the frequency of Lp(a) screening across the University of Rochester Medical Center (URMC). Descriptive data were collected for all URMC patients >= 18 years old who have had at least one Lp(a) measurement from January 2011 to August 2022 from the URMC electronic health record (EHR). Cardiovascular diagnoses were queried to define yearly frequency and demographic information. We identified 2,698 patients with at least one Lp(a) result. An increasing number of patients were tested per year. There were more women than men, and about 11% having more than one Lp(a) measured with the majority having a level <30 mg/dL (the normal-range in the UMRC lab). The majority do not have a listed diagnosis of cerebral infarction, peripheral vascular disease, myocardial infarction, coronary artery disease, or aortic stenosis. Across URMC, there has been a steady increase of Lp(a) measurements in the past several years.
Trends and consequences of lipoprotein(a) testing: Cross-sectional and longitudinal health insurance claims database analyses
2023, Atherosclerosis
Lipoprotein(a) (Lp(a)) is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Our goal was to characterize patients undergoing Lp(a) testing and to assess the impact of Lp(a) testing on treatment changes and subsequent ASCVD events.
A cross-sectional and a longitudinal claims data analysis were performed on 4 million patient records in Germany. Patients were followed up for a maximum of 4 years.
In 2015 and 2018, 0.25% and 0.34% of patients were tested, respectively. Testing was more frequent in younger women in the overall population, and in men in the ASCVD population. Patients tested for Lp(a) had more comorbidities and higher ASCVD risk compared to matched control patients. ASCVD hospitalizations were more frequent prior to the first Lp(a) test (5.55 vs 1.42 per 100/person-years). The mortality rate of the Lp(a)-tested cohort and the control group was similar. Mortality was lower in patients with prior ASCVD and Lp(a) testing compared to matched controls with prior ASCVD and no Lp(a) test (2.30 vs 3.64 per 100/person-years, p <0.001). Patients with Lp(a) test received more laboratory examinations and cardiovascular medications and had more visits with specialized physicians.
Lp(a) testing is rarely performed even in patients with very high cardiovascular risk. Patients tested for Lp(a) have more comorbidities and a higher ASCVD risk. Lp(a) testing is associated with more intensive preventive treatment and with positive effects on clinical outcomes and survival. The data support the value of Lp(a) measurements to characterize ASCVD risk and to improve ASCVD prevention.
Lipoprotein(a) and Cardiovascular Disease: A Missing Link for Premature Atherosclerotic Heart Disease and/or Residual Risk
2022, Journal of Cardiovascular Pharmacology

: Disclosures/Acknowledgements: This study was supported by a grant from Amgen, Inc. MDK is supported by a National Institute of Health (NIH) training grant (NIH 5T32HL069749-17).

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Lipoprotein(a) Testing Patterns in a Large Health System

Section snippets

Methods

Results

Discussion

Disclosures

Lancet

J Am Coll Cardiol

J Am Coll Cardiol

J Am Coll Cardiol

J Clin Lipidol

J Clin Lipidol

Atherosclerosis

J Am Coll Cardiol

J Am Coll Cardiol

Atheroscler Suppl

J Am Coll Cardiol

Metabolism

The role of lecithin: cholesterol acyltransferase for lipoprotein (a) assembly. Structural integrity of low density lipoproteins is a prerequisite for Lp(a) formation in human plasma

J Clin Invest

Genetic variants associated with Lp(a) lipoprotein level and coronary disease

N Engl J Med

Lipoprotein(a), fibrin binding, and plasminogen activation

Arteriosclerosis