Key Points
- Statins are among the most widely prescribed and thoroughly researched medications in the world, and the evidence for their benefit in reducing heart attacks and cardiovascular death is robust.
- A coronary calcium score measures the amount of calcium in the artery walls and is a useful marker of atherosclerosis, but it does not tell the whole story on its own.
- Some patients on statins see their calcium score rise over time. This can feel alarming, but emerging evidence suggests it may actually reflect the plaques becoming more stable, not more dangerous.
- Statins appear to shift plaques from a vulnerable, fatty state toward a harder, more calcified and stable state, reducing the risk of rupture even as the calcium score increases.
- If you are on a statin and concerned about your calcium score or side effects, the right conversation to have is with your doctor, not with the internet.
Statins are one of those medications that almost everyone has heard of, and that attract a remarkable amount of debate, both online and in the doctor’s office. They are among the most prescribed drugs in the world. Decades of rigorous clinical trial data show they meaningfully reduce the risk of heart attack, stroke, and cardiovascular death in people at elevated risk.
Yet questions about statins persist, particularly around side effects, and more recently around what they do to coronary calcium scores. If you have had a calcium score test and been told it has gone up despite being on a statin, it is understandable to feel confused or concerned. This article explains what is actually happening, and why the picture is more reassuring than it first appears.
What is coronary atherosclerosis?
Atherosclerosis is the process by which plaques, made up of cholesterol, fat, calcium, and inflammatory cells, gradually build up inside the walls of the coronary arteries. Over time, these plaques can narrow the arteries and restrict blood flow to the heart muscle.
The real danger with atherosclerosis is not always the degree of narrowing. It is the stability of the plaque. A plaque that is soft, fatty, and inflamed on the inside is far more likely to rupture, triggering a clot that can completely block the artery and cause a heart attack, than one that is harder and more calcified. Understanding plaque composition, not just plaque burden, is at the heart of modern cardiovascular risk assessment.
What does a coronary calcium score tell us?
A coronary calcium score is obtained from a CT scan of the heart. It measures the amount of calcium deposited within the coronary artery walls and gives a number, the higher the score, the greater the calcified plaque burden. It is a useful screening tool, particularly in people whose cardiovascular risk is uncertain, helping to guide decisions about whether to start preventive treatment.
What the calcium score does not tell us is the composition of the plaques, whether they are soft and vulnerable or hard and stable. Two people with the same calcium score can have very different levels of actual risk depending on what is inside those plaques. This is where the story around statins becomes particularly interesting.
What do statins actually do?
Statins work primarily by reducing LDL cholesterol, the so-called “bad” cholesterol that plays a central role in the formation of atherosclerotic plaques. But their benefits go well beyond cholesterol lowering. Statins also reduce inflammation within plaques, stabilise the fibrous cap that holds plaques together, and reduce the risk of rupture. These effects, collectively, are why statins so consistently reduce heart attacks and cardiovascular death in clinical trials, independent of exactly how much they lower the cholesterol number.
Statins are not perfect, no medication is. But the evidence base behind them is genuinely strong, and for patients at elevated cardiovascular risk, the benefits almost always outweigh the risks. The key is identifying the most appropriate patients who will benefit and not simply prescribing them because of a high cholesterol number.
For most people, statins are well tolerated. Some experience muscle aches, which are worth discussing with your doctor, dose adjustment or switching to a different statin often resolves the issue. Serious side effects are rare. The volume of misinformation about statins online is unfortunately significant, and it leads some people to stop a medication that is genuinely protecting them.
The statin paradox, why does the calcium score sometimes go up?
Here is where things get counterintuitive, and genuinely fascinating from a scientific standpoint. Some patients who have been on statin therapy for a period of time have their calcium score repeated and find it has increased. Understandably, this can cause alarm. If statins are supposed to help, why has the score gone up?
The emerging explanation is that statins are doing exactly what they should, but the calcium score is not measuring what people assume it is measuring. As statins reduce the lipid and inflammatory content within plaques, those plaques appear to undergo a process of calcification, becoming harder and more mineralised. The calcium score rises, but the plaques themselves are becoming more stable and less likely to rupture.
| Plaque type | Characteristics | Risk of rupture |
|---|---|---|
| Soft, lipid-rich plaque | Fatty core, thin cap, inflamed, common in untreated disease | Higher |
| Calcified, stable plaque | Hard, mineralised, thick cap, seen more in statin-treated patients | Lower |
Think of it this way, a plaque that looks more concerning on a calcium score may actually be in a safer state than a plaque that barely registers. The score is going up, but the danger is going down. This is what researchers refer to as the statin paradox, and it has important implications for how we interpret calcium scores in patients already on treatment.
How do we visualise plaques more precisely?
For patients where a more detailed picture of plaque composition is needed, advanced imaging techniques are available. CT coronary angiography can provide information about both the degree of narrowing and the nature of the plaques, distinguishing between calcified and non-calcified components. In the catheter laboratory, intravascular ultrasound and optical coherence tomography allow extraordinarily detailed assessment of plaque structure from the inside of the artery.
These tools are not needed for everyone, they are reserved for situations where the clinical picture is complex or uncertain. For most patients on statin therapy, a rising calcium score in isolation is not a reason to panic or to change treatment.
What does this mean for your care?
If you are on a statin and your calcium score has increased at a repeat scan, the most important thing is to discuss this with your cardiologist in the context of your full clinical picture. A rising score does not automatically mean your disease is progressing in a dangerous way, it may be a sign that your treatment is working at the plaque level in exactly the way it is supposed to.
What matters most is your overall cardiovascular risk profile, your blood pressure, cholesterol levels, lifestyle, and whether you are adhering to your medications. These are the levers that make the biggest difference to long-term outcomes, and they are the ones worth focusing on.
Questions to Ask Your Cardiologist
If you have had a calcium score test or are on statin therapy, here are some useful questions to bring to your next appointment:
Questions worth asking
- My calcium score has gone up since starting a statin, does this mean my disease is progressing, or could it reflect plaque stabilisation?
- Should I have a repeat calcium score, or are there other tests that would give a more complete picture of my plaque composition?
- I am experiencing muscle aches on my current statin, is there an alternative dose or medication worth trying?
- Given my calcium score and overall risk profile, is my current statin dose appropriate, or should we consider intensifying treatment?
Conclusion
The relationship between statins and coronary calcium scores is a reminder that medicine is rarely as simple as a single number. A rising calcium score in a statin-treated patient is not the straightforward bad news it might appear to be, it may reflect a shift toward more stable, less dangerous plaques, which is precisely what effective treatment looks like at the arterial level.
Statins remain one of the most important tools we have in cardiovascular prevention. The research around plaque composition and calcium scoring is evolving, and as imaging technology continues to improve, our ability to interpret these findings with greater precision will only grow.
If you have questions about your calcium score, your statin, or your cardiovascular risk more broadly, bring them to your doctor. A well-informed patient who understands their treatment is always in a stronger position, and that conversation is one of the most valuable things you can have.
Free Resources
Our Heart Glossary explains terms like atherosclerosis, LDL cholesterol, calcium score, and plaque in plain language.
