Alirocumab (PCSK9i) Helps Clear Heart Artery Plaque—But Works Best in Lower-Risk Patients

#1

This study looked at whether alirocumab (a PCSK9 inhibitor that dramatically lowers LDL cholesterol) can shrink plaque inside heart arteries when added to a strong statin in people who recently had a heart attack. The focus was whether patients at very-high risk (older, more medical problems) respond differently from lower-risk patients.

Researchers used three imaging methods that let them see inside the coronary arteries:

  • IVUS (Intravascular Ultrasound): tiny ultrasound probe inside the artery to measure how much plaque there is .
  • NIRS (Near-Infrared Spectroscopy): shows how much of the plaque is made of dangerous oily “lipid core.”
  • OCT (Optical Coherence Tomography): a laser-based camera that measures how thick and stable the fibrous cap is —thin caps are vulnerable to rupture.

All scans were done right after the heart attack and again one year later.

How Much Plaque Was Reduced?

The main result was the change in percent atheroma volume (PAV)—basically, “how much of the artery wall is filled with plaque.”

Non–Very-High-Risk (non-VHR) group: strongest improvement

  • Alirocumab: plaque shrank by –2.5%
  • Placebo: shrank by –0.9% → Net improvement caused by alirocumab: –1.8%

This is substantial because prior research shows every 1% drop in plaque volume links to ~14% fewer future heart events.

Very-High-Risk (VHR) group: smaller improvements

  • Alirocumab: –1.7%
  • Placebo: –1.1%→ Net improvement: –0.8%, barely significant.

Lipid (fatty) content of plaque

Non-VHR patients again saw much larger reductions in dangerous lipid-rich plaque compared to VHR patients.

Inflammation inside plaque

Measured by “macrophage angle” (how much immune-cell infiltration is present).

Non-VHR patients again improved far more.

Stability of plaque cap

VHR patients slightly outperformed non-VHR here—likely because they started with thinner, weaker caps, giving more room for improvement.

Why Does Alirocumab Work Better in Lower-Risk Patients?

The arteries of VHR patients are often:

  • older
  • stiffer
  • more scarred or calcified
  • more affected by high blood pressure or long-term smoking

These arteries are less biologically flexible, meaning plaque is harder to reverse even when LDL is reduced to very low levels.

Lower-risk patients seem to have more “reversible” plaque, which responds more strongly to intensive LDL lowering.

What’s New Here?

This is the first study to show that plaque shrinkage from PCSK9 inhibitors depends strongly on a patient’s overall risk profile.

It challenges the usual assumption that “higher-risk patients benefit the most.”

Actionable Takeaways (for general readers)

  • The people who gain the most plaque shrinkage are those who don’t have many traditional risk factors.
  • Keeping blood pressure controlled, not smoking, and reducing inflammation likely makes major LDL reduction more effective.
  • Alirocumab is expensive, so the best value is in people who can still “reverse” plaque.

Limitations

  • Substudy, not originally planned for this comparison.
  • VHR group was smaller and more complex medically.
  • One year is short; clinical events (heart attacks, death) weren’t the primary endpoint here.

10 Questions an Interested Non-Scientist Might Ask

  1. How do I know if I’m in the “very-high-risk” or “lower-risk” category?
  2. Would lowering my LDL even further meaningfully shrink my own plaque?
  3. Should I get a coronary CT scan to see if my plaque is the “reversible kind”?
  4. Is expensive therapy like alirocumab worth it for me compared to stronger statins or lifestyle changes?
  5. If I have high blood pressure or long-term smoking history, will that blunt my results?
  6. Does lowering LDL this aggressively improve life expectancy, or mainly reduce heart-attack risk?
  7. If my plaque does shrink, how quickly does that translate into lower risk?
  8. Can I take alirocumab temporarily (“plaque reversal phase”) instead of long-term?
  9. Are there supplements or lifestyle changes that enhance plaque regression?
  10. If my Lp(a) is high, will PCSK9 inhibitors help with plaque reversal or only slightly?

Full Paper (open access): Effect of alirocumab on coronary plaque stratified by atherothrombotic risk

4 Likes
#2

Alirocumab is relatively expensive.
Alternatively you could consider Nattokinase
New Study Reveals: High-Dose Supplement Shrinks Arterial Plaque by 36%
I have had a series of CAC scans 8/22 score was 287, 6/24 score was 242 after starting Nattokinase 8000 F units (Naturebell product) in late 2023
I’ll do another CAC scan in mid 2026 and will post results after that.

4 Likes
#3

Have you got the result from 2026 scan?

#4

Test is scheduled for later this month, so results by end of the month.

1 Like
#5

What part of this change in CAC score can be explained by measurement variation or noise?

Why are you using CAC instead of CCTA?

Why do you believe Nattokinase could be an equivalent alternative to alirocumab effect wise?

#6

The OpenEvidence AI says that CAC results are +/- up to 20%, perhaps even more on some scanners, so a lot of variation could be related to lack of scan accuracy.
I have used CAC to this point because of cost (eg $ 100 vs $ > 1K per scan ) and because of the higher irradiation with CTA vs CAC (ie 5 - 15 mSv, vs 0.5 - 1.5mSV for CAC)
Background radiation is approx 2.5 mSV/year.
( I will use pre CTA melatonin 200mg 2 hours before the scan to mitigate radiation damage )
My lipid measurements are relatively good on 40mg qd Rosuvastatin and Exetimibe.
(LDL-c 40, ApoB 74, but I have metabolic syndrome with somewhat elevated TGs, and low HDL)
I’m also not keen on injectables, so have avoided thinking about PCSK9i to this point.
However with newer oral PCSK9i becoming available, in addition to looking at CAC ? stability, I wanted to look at soft plaque.
Also since I’m asymptomatic I haven’t felt pressured to go with injectable PCSK9i, despite my elevated Lp(a)
See the article quoted above regarding Nattokinase effect on plaque.
So I’m basically trying to see if high dose Nattokinase will work as well for me as reported in the article.
Another N = 1.
I’ll post again in more detail after I’ve had the CTA.

#7

Check your RW-ApoB result: https://www.rwapob.com/

A better approach might be to get a CCTA with Heartflow with a doctor and decide how to best reduce the risk of events. The evidence doesn’t justify to do serial CAC test with nattokinase IMO. There are no outcome studies. We know other drugs and targets for outcomes like heart attack or stroke.

See this thread for possible treatments options depending on the result.

For example, DM treatment, or weight loss treatment if applicable, blood pressure treatment, aspirin in some cases. Lowering apoB further. That’s a way better idea especially if you say you have metabolic syndrome. YMMV and not medical advice.

Treating the metabolic syndrome should be way higher priority than serial CAC tests, and making sure other markers are in optimal ranges IMO. Imaging is more to motivate to treat (except edge cases of deciding whether to take aspirin under a doctor’s care, for instance, or biohackers like Simon Hill that tries to regress early atherosclerosis).