Doctors learn a patient's Lp(a) is dangerously high - and 80% of the time, do nothing

There is a blood marker that roughly one in four people carry at dangerous levels, one that independently raises the risk of heart attack and stroke, and one that clinicians are testing for more frequently than ever. It is called lipoprotein(a), or Lp(a). And when doctors find it elevated, they overwhelmingly do nothing about it.

That is the central finding of a multicenter retrospective study presented at the American College of Cardiology and published in the American Journal of Preventive Cardiology. Among nearly 15,000 patients at low risk for atherosclerotic cardiovascular disease (ASCVD), almost 80% of those with Lp(a) above 50 mg/dL received no lipid-lowering therapy within 90 days of testing.

A risk factor without a clear playbook

The finding is less damning than it sounds. Lp(a) occupies an awkward position in cardiology: it is genetically determined, meaning lifestyle changes do not budge it, and no approved drug specifically targets it. Current guidelines recognize elevated Lp(a) as a "risk enhancer" - a factor that might tip a borderline patient toward more aggressive prevention - but not as a standalone treatment indication.

So when a clinician sees an Lp(a) result of, say, 75 mg/dL in an otherwise healthy 45-year-old, the guidelines offer no clear instruction. Start a statin? The evidence for statin benefit specifically driven by Lp(a) is limited. Prescribe a PCSK9 inhibitor? Those drugs do lower Lp(a) modestly, but they are expensive and not indicated for Lp(a) alone.

The result, according to the study, is selective and inconsistent prescribing. Lipid-lowering therapy initiation was uncommon across the board but somewhat more frequent among patients with elevated Lp(a) compared to those with normal levels. PCSK9 inhibitor use was rare in both groups. Aspirin prescriptions followed the same pattern - slightly more common with high Lp(a), but still unusual.

Describing practice, not prescribing it

Corresponding author Sheilah A. Bernard, an associate professor of medicine at Boston University Chobanian & Avedisian School of Medicine and a cardiologist at Boston Medical Center, was careful to frame the results. The study describes what clinicians are doing, not what they should be doing. In a population at low baseline cardiovascular risk, the absence of aggressive treatment may be entirely reasonable.

But the findings do highlight a growing tension in cardiology. Testing for Lp(a) has surged in recent years, driven partly by its prognostic value and partly by the emergence of targeted therapies now in late-stage clinical trials. Several RNA-based drugs designed to slash Lp(a) by 80% or more are working through phase 3 studies. If those drugs reach the market, the clinical calculus could shift dramatically - and the gap between testing and treatment will need to close.

What the study did not measure

The study tracked prescribing within 90 days of Lp(a) measurement, which may not capture the full clinical response. Some physicians may have used the result to intensify monitoring, adjust risk calculations, or counsel patients about lifestyle factors that affect overall cardiovascular risk even if they do not change Lp(a) itself. None of those responses would show up as a new prescription.

The patient population was also low-risk by design, with no established ASCVD. In higher-risk populations, elevated Lp(a) may well prompt more aggressive intervention. The study does not address that scenario.

It is also a retrospective observational analysis, which means it can describe patterns but cannot determine whether the treatment decisions were appropriate for individual patients. A physician who decides not to start a statin in a low-risk patient with elevated Lp(a) may be making a perfectly defensible call.

The pipeline that could change everything

The broader context matters. Lp(a) has been a known risk factor for decades, but it has been largely untreatable. That is about to change. Drugs like pelacarsen and olpasiran have shown dramatic Lp(a) reductions in clinical trials, and outcomes data should emerge in the next few years. If those drugs prove they prevent heart attacks and strokes, the current pattern of testing-without-treating will look very different in hindsight.

For now, the study captures a field in transition. Clinicians are testing more, understanding more, and - in most cases - waiting for better tools before acting. Whether that wait is prudent or perilous depends on answers that are still coming.