Lipoprotein(a), said L-P-little-A, is a genetic cholesterol particle that drives heart attacks and aortic valve narrowing. About 1 in 5 adults carry high levels. It is not on standard cholesterol panels. We test every patient once because the result rarely changes and it shapes lifelong prevention.
Someone 45 years old, a marathon runner who eats vegan and looks as lean and healthy as anyone in the room, has a massive heart attack on Kelly Drive. The autopsy shows arteries full of plaque. Every cholesterol panel that person ever had came back "normal."
Almost every time a story is shaped like that one, Lipoprotein(a) is what was driving it.4
The I-676 metaphor
Picture the Vine Street Expressway (I-676) at rush hour, and picture your arteries the same way:
- ApoB is the traffic volume. Put enough cars on the road and you get the jams, which inside an artery is plaque.
- Lp(a) is no ordinary sedan. Think of a Mad Max rig rolling down the middle lane on spiked wheels.
Traffic can be light and your ApoB can be low, and one of those cars will still sideswipe the guardrail, catch two others on the way through, and start a fire. The spiked wheels are a sticky tail on the particle itself. It catches on your artery wall instead of passing by, works its way in, pulls inflammation in behind it, and gums up the crew your body sends to dissolve clots.
Why do standard labs miss Lp(a)?
Your annual panel skips Lp(a) for a historical reason: for decades there was nothing to offer the person whose number came back high. About 90% of your level is written into the genes you inherited, so a high number was already high on the day you were born and will still be high on the day you die. It does not come down because you ate more salad this year. A number nobody could move became a number the field stopped asking about, and the reasoning was that a result you cannot change is a result you do not need.
That reasoning turned out to be wrong. Your Lp(a) tells us how hard to push on every other risk factor you carry, and those are the ones that do move.
How do we manage high Lp(a)?
Nothing on the pharmacy shelf today targets Lp(a) itself, so we lower the risk sitting around it and keep an eye on what is coming. PCSK9 inhibitors such as evolocumab, sold as Repatha, can take Lp(a) down by roughly 25-30% on their own. Two gene-silencing drugs, pelacarsen and olpasiran, are in late-stage trials.23 If you want the detail on how those work and where the evidence stands, our full guide to the new Lp(a)-lowering drugs goes through it. Until then, your risk in aggregate is what we treat.
Back on the expressway, if Lp(a) is the car looking for a crash, our work is on the road it drives:
- Clear the road: We take your ApoB down toward 30-40 mg/dL with a statin, ezetimibe, or a PCSK9 inhibitor. The PCSK9 drugs are the ones that pull double duty, since they lower ApoB and Lp(a) at the same time.
- Install guardrails: We hold your blood pressure near 120/80 and run your blood sugar tighter than the standard target, both to protect the artery wall your Lp(a) keeps scraping.
- Daily low-dose aspirin (when appropriate): Lp(a) adds clotting risk, and aspirin answers that. We go through your bleeding risk together before you start.
- Image early: A CT Coronary Angiogram (CTA) read with Cleerly AI in your 40s shows us whether soft plaque is there already, and how hard we treat gets matched to what the scan finds.
Actionable Steps in Philly
One blood test, one time, and it shapes your prevention for the rest of your life.
- Ask for Lp(a) by name the next time you get blood drawn. Cash price around here is usually about $40.
- Treat anything above 75 nmol/L (or 30 mg/dL) as a number that changes the plan. Above 125 nmol/L (or 50 mg/dL) puts you in the high-risk group.
- Get your ApoB under 60 mg/dL if your Lp(a) comes back high.
- Cascade test the family. Parents, siblings, and children each carry a 50% chance of having it, and a standard panel will not show it to them.
Key Takeaways
- Test Once: Levels stay stable for life. You only need to check this once.
- Family Risk: If you have it, your siblings and children each have a 50% chance of having it. Cascade screening saves lives.
- Aortic Stenosis: High Lp(a) also calcifies the aortic heart valve. We listen carefully for murmurs and order imaging when indicated.1
Scientific References
- Kronenberg F, et al. "Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement." European Heart Journal. 2022.
- Tsimikas S, et al. "Lipoprotein(a) Reduction in Persons with Cardiovascular Disease." New England Journal of Medicine. 2020.
- O'Donoghue ML, et al. "Small Interfering RNA to Reduce Lipoprotein(a) in Cardiovascular Disease." New England Journal of Medicine. 2022.
- Reyes-Soffer G, et al. "Lipoprotein(a): A Genetically Determined, Causal, and Prevalent Risk Factor for Atherosclerotic Cardiovascular Disease." Arteriosclerosis, Thrombosis, and Vascular Biology. 2022.
Related Articles:
Dr. Ash is a board-certified internal medicine physician at Fishtown Medicine in Philadelphia. He practices advanced preventive cardiology with a focus on identifying and managing genetic cardiovascular risk early.
Related at Fishtown Medicine
- Borderline Cholesterol: How ApoB, Lp(a), and Blood Pressure Change the Plan - a patient case where 3 unmeasured numbers turned "recheck in a year" into a plan
- Stroke Prevention in Philadelphia - the 2024 AHA/ASA guideline applied across BP, GLP-1, diet, CRF, and insulin resistance
- ApoB and Heart Health - the cholesterol particle count that predicts heart attacks far better than standard LDL
- Lp(a) and Cholesterol - why you can have perfect cholesterol and still be at high risk
- ED and Cardiovascular Risk - erectile dysfunction as the earliest warning sign of vascular disease
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