UC San Diego Study Finds Lipoprotein(a) Testing Rare Across US
Despite links to cardiovascular risk, only 0.2% of Americans received an Lp(a) test over the past decade, raising concerns about access, equity, and preparedness for new therapies.
A large-scale analysis led by the University of California San Diego School of Medicine has revealed that testing for lipoprotein(a) [Lp(a)]—a genetic marker strongly associated with cardiovascular risk—remains uncommon in the United States, despite recent increases.
For lab leaders, the findings highlight both the challenges of uneven adoption and the opportunities to drive greater awareness, access, and equity as new therapies approach the market.
The study was published September 26 in Journal of the American College of Cardiology: Advances, used Epic Cosmos, a nationwide database encompassing over 300 million patient records from health systems in all 50 states. It marks the first time Epic Cosmos has been used at this scale within the University of California system, and the first study to assess national patterns of Lp(a) testing at this volume.
Lp(a) is a cholesterol particle in the blood that is almost entirely determined by genetics. Elevated levels, which affect about 20% of the US population, are linked to significantly higher risk of heart attack, stroke, and aortic valve disease. Unlike LDL cholesterol, Lp(a) does not respond to diet or lifestyle changes, and currently there are no widely available therapies to lower it—though several are in late-stage clinical trials.
US Testing Rates Remain Low
An article on the study stated, “They found that between 2015 and 2024, just 728,550 patients, representing only 0.2% of the US population, underwent Lp(a) testing. Testing increased from about 14,000 patients in 2015 to more than 300,000 in 2024, but overall rates remain far below what experts recommend for identifying individuals at risk.”
European nations are moving toward universal Lp(a) screening as a key early predictor of heart disease, while the U.S. continues to lag behind.
“By analyzing national data from over 300 million patients, we’ve uncovered how much work remains to bring Lp(a) testing into routine care,” said Mattheus Ramsis, MD, lead author and assistant professor of medicine at UC San Diego School of Medicine.
Mattheus Ramsis, MD, lead author and assistant professor of medicine at UC San Diego School of Medicine noted, “These insights give us a roadmap for expanding access and addressing gaps. We’re seeing a growing recognition among clinicians of the importance of Lp(a) testing, but the low overall testing rates and regional imbalances highlight how much further we need to go. Broader awareness and access to testing could make the difference between catching disease early and missing an opportunity to prevent heart attacks and strokes, ensuring that all patients benefit from emerging therapies.” (Photo credit: UC San Diego Division of Cardiovascular Medicine)
Testing Patterns
The UC San Diego study found stark inequities in testing patterns. Adults aged 50 to 65 were most likely to be tested, and testing was nearly equal between men and women. But less than 10% of patients tested were Black and only 7% were Hispanic or Latino, despite both groups being disproportionately impacted by cardiovascular disease.
“We’re seeing a growing recognition among clinicians of the importance of Lp(a) testing, but the low overall testing rates and regional imbalances highlight how much further we need to go,” Ramsis said. “Broader awareness and access to testing could make the difference between catching disease early and missing an opportunity to prevent heart attacks and strokes, ensuring that all patients benefit from emerging therapies.”
Geographic disparities also stood out. California, Ohio, and Texas accounted for more than a quarter of all tests nationwide, while some states saw almost no uptake. Researchers say this uneven adoption underscores the need for clearer national guidelines and more consistent payer coverage to make Lp(a) testing accessible everywhere.
The study also noted that there was a shift in how tests are being conducted. The article said, “In 2015, most measurements used older ‘mass-based’ assays, which measure the total weight of Lipoprotein(a) in a blood sample. However, by 2024, two-thirds of tests were performed using the more accurate molar assays, in line with evolving clinical guidelines. Molar assays measure the actual number of Lp(a) particles in a person’s bloodstream to assess cardiovascular disease risk, rather than just the mass of particles.”
Co-author Ehtisham Mahmud, MD, professor of medicine and chief of the Division of Cardiovascular Medicine at UC San Diego, stressed the importance of laboratories in expanding adoption.
Mahmud commented, “The rise in testing is encouraging, but we are still far from where we need to be. If we want to close the gaps in cardiovascular risk assessment, especially in underserved communities, we need broader education, clearer guidelines and consistent insurance coverage for Lp(a) testing.”
For laboratory leaders, one of the most important steps in closing the gap on Lp(a) testing is proactive communication with physicians. Many clinicians may not be fully aware of the latest guidelines recommending at least one lifetime Lp(a) test for adults, or of the shift from mass-based to molar assays that better assess cardiovascular risk.
Lab leaders can play a central role by educating providers on when and why to order the test, sharing local testing capacity, and emphasizing how results may guide risk stratification as new therapies reach the market. By positioning themselves as trusted partners in cardiovascular prevention, labs can help physicians incorporate Lp(a) testing into routine practice, expand access to high-risk patients, and ultimately strengthen patient outcomes.
—Janette Wider
