A little, in some people, under intensive treatment. Trials that measured plaque inside the coronary arteries found that strong LDL lowering can shrink it, but by a small amount: around one to two percentage points of plaque volume over one to two years. Plaque does not melt away.
That is why specialists talk less about reversal and more about stabilization. The aim of treatment is plaque that is less likely to rupture and fewer heart attacks and strokes. Nobody can promise that your plaque will shrink, and no test result can promise that you will not have a heart event.
Key takeaways
- Measured shrinkage of coronary plaque in trials is real but modest, about one to two percentage points of plaque volume.
- These results came from intensive prescription LDL lowering in people with established coronary disease, tracked with invasive imaging.
- Even at very low LDL levels, a sizable share of trial patients showed no regression.
- Treatment also changes what plaque is made of, which may matter more than its size.
- Stabilizing plaque and lowering the chance of events is the goal, and no one can promise regression.
How regression is measured
The regression trials used intravascular ultrasound: a tiny ultrasound probe threaded into a coronary artery during a catheter procedure. It measures percent atheroma volume, the share of the artery wall that is taken up by plaque.
This is a research tool used in people who already need a catheter procedure. It is not a screening test. A calcium score and a carotid ultrasound measure different things, and neither can show the kind of change these trials reported. For the basics, see what arterial plaque is.
What three key trials found
| Trial | Who and what | Change in plaque volume |
|---|---|---|
| ASTEROID (2006) | 349 patients on very high-intensity statin therapy for 24 months | Average fall of 0.98 percentage points |
| GLAGOV (2016) | 968 statin-treated patients with coronary disease, PCSK9 inhibitor or placebo added for 76 weeks | Fall of 0.95 points with the added drug, rise of 0.05 with placebo |
| PACMAN-AMI (2022) | 300 patients after a heart attack, PCSK9 inhibitor or placebo added to a high-intensity statin for 52 weeks | Fall of 2.13 points with the added drug, 0.92 with placebo |
What those numbers mean
In ASTEROID, average LDL cholesterol fell from 130.4 to 60.8 mg/dL, and percent atheroma volume fell by an average of 0.98 percentage points over 24 months.1 The trial had no comparison group, so it showed that regression can happen, not how much more than with standard care.
GLAGOV added a control group. In GLAGOV, percent atheroma volume fell by 0.95 percentage points in the group that reached an average LDL cholesterol of 36.6 mg/dL, and regression was seen in 64.3% of those patients compared with 47.3% on a statin alone.2
Read that second figure both ways. Most patients on the most intensive treatment had some regression. More than a third did not, even with LDL cholesterol far below usual targets. And nearly half of the patients on a statin alone showed regression too.
PACMAN-AMI studied people in the year after a heart attack and found that percent atheroma volume fell by 2.13 percentage points with the combination and 0.92 with a high-intensity statin alone.3
So the honest word is modest. These are changes of one to two percentage points, measured with a precise invasive tool, in people who already had coronary disease and were taking intensive prescription treatment.
Why stabilization matters more than shrinkage
Many heart attacks start when a plaque ruptures. The plaques most prone to rupture tend to be large, rich in fat and covered by a thin fibrous cap. Our comparison of soft and calcified plaque explains the difference.
Treatment changes that makeup. In PACMAN-AMI, the fatty content of plaque fell and the fibrous cap thickened more with the added drug than with the statin alone. A second imaging trial in statin-treated patients after a heart attack found that the fibrous cap thickened by 42.7 micrometers with an added PCSK9 inhibitor and 21.5 micrometers with placebo, changes its authors described as consistent with stabilization.4
Statins also make plaque more calcified. An analysis of eight ultrasound trials found that statins promote calcification of plaque, even while high-intensity statins shrink it.5 This is why a calcium score is not expected to go down on treatment and can go up. See what a rising calcium score means.
Does shrinking plaque mean fewer heart attacks?
It appears to travel with fewer events, but the link is not proven to be cause and effect. A meta-regression of 23 imaging trials with 7,407 patients found that each 1% decrease in average plaque volume was associated with 17% lower odds of major cardiovascular events, and its authors cautioned that more data are needed.6
The firm evidence for LDL-lowering medicines comes from large outcome trials that counted heart attacks and strokes, not from imaging. Imaging trials help explain why those medicines work.
What the trials do not show
- They do not show that plaque disappears. Most of it remains.
- They do not show regression in people without established coronary disease, because those people were not studied this way.
- They did not test supplements, and they did not test lifestyle change alone as the treatment.
- They do not predict what will happen in any one person.
The treatments in these trials were prescription medicines chosen and monitored by physicians. Do not start, stop or change a medication without your prescriber, and be wary of any product or program that promises to clear your arteries.
Next step: know your starting point
You cannot track regression with a routine test, but you can find out where you stand. The Cardio Res-Q Enhanced Assessment ($999) adds a coronary calcium score and a CIMT ultrasound to the labs and clinical evaluation in the Comprehensive Assessment ($775). The calcium score shows calcified plaque only. For CIMT, US guidance from 2013 does not recommend routine use for predicting a first heart event, and carotid plaque predicts risk better than wall thickness.
Neither scan measures plaque volume the way the trials did. If you are already treated, read Already on a Statin? before choosing, then see the Cardio Res-Q program page.
Are You a Candidate for Cardio Res-Q?
Three quick questions about the risk factors we screen for. Your answers stay between you and the clinic.
Frequently asked questions
Can statins remove plaque from arteries?
They do not remove it. In trials of intensive statin therapy, plaque volume fell slightly on average, and plaque became more stable and more calcified. The main proven benefit of statins is fewer heart attacks and strokes.
Can diet and exercise alone shrink plaque?
The regression trials described here tested intensive prescription LDL lowering, not lifestyle change alone, so they cannot answer that. Healthy habits lower heart risk through several routes and are part of every treatment plan, but shrinkage should not be assumed.
Will my calcium score go down with treatment?
It is not expected to. Statins tend to increase the calcium in plaque as they stabilize it, so a score can rise on treatment without meaning the disease is worse. A calcium score is a poor tool for tracking progress on medication.
How low does LDL have to be for plaque to regress?
There is no level that makes regression certain. In the trials, regression was more common at lower LDL levels, yet some patients at very low levels still had none. Your LDL goal is a decision for you and your clinician, based on your overall risk.
Related reading
This article is for general education and is not medical advice. Decisions about testing and medication should be made with your clinician. If you have chest pain or other symptoms of a heart attack, call 911.
