What causes atherosclerosis?

What causes vascular calcification? In some people, calcium accumulates in the walls of the coronary arteries. It is the calcium circulating in the blood that forms this calcification. As the calcification in the vessel increases, the vessel hardens; in very advanced stages of calcification, it can even become stone-like. Consequently, the vessel cannot expand when needed because it has lost its natural elasticity. The calcification process develops gradually over the years. In the first stage, cholesterol and inflammatory cells infiltrate the inner surface of the vessel, forming irregularities called plaques. These plaques grow over time. Some cells in the vessel wall transform into a structure almost similar to bone cells, thereby accelerating calcium accumulation. Calcifications that are very small at the beginning merge over the years to turn into large and hard calcium plaques. In 7 out of every 10 people over the age of 70, there is at least some degree of calcification. Severe calcification is seen in relatively fewer people. Poor dietary habits, a sedentary lifestyle, and chronic stress also accelerate this process. The most important causes that trigger calcium formation are:
  • Old age
  • Diabetes
  • Chronic kidney failure
  • High blood pressure
  • High cholesterol
  • Smoking
  • Genetic predisposition

How is atherosclerosis diagnosed?

Imaging devices are used to visualize calcification. The most common scenarios we encounter when diagnosing calcified vessels are as follows:
  • Accidental detection of calcification in the coronary arteries or the aorta during a computed tomography (CT) scan performed for another organ, such as the lungs.
  • Detection of calcification during a computed tomography scan performed for a cardiac check-up (calcium score).
  • Detection of calcification during cardiac angiography.
How to Open a Calcified (Hardened) Artery?

Computed tomography images showing calcification in the coronary arteries of three different patients (white spots indicated by arrows)

 

What is the calcium score?

The amount of calcium accumulated in the vessel walls can be determined by computed tomography using a very low dose of radiation. As the extent of calcification increases, the score provided by the device also increases. This value is called the “calcium score.” Generally, calcium score measurement is used to distinguish between individuals at low, intermediate, and high risk. In other words, it is used to better predict the actual risk of events like a heart attack for patients who are in a “grey zone” regarding risk factors such as smoking, blood pressure, or cholesterol. For example, a middle-aged smoker who is assumed to be in a high-risk group may be revised to the intermediate-risk group if their calcium score turns out to be zero, and an angiography may no longer be necessary. The calcium score grading is summarized as follows:
How to Open a Calcified (Hardened) Artery?
Calcium scoring: The more calcium deposits (red arrows) there are, the higher the calcium score.
It is not possible to determine whether there is a blockage in the vessels using a computed tomography scan performed solely for a calcium score. Therefore, when performing a check-up for those with risk factors, it is generally more accurate to perform a CT angiography (virtual angiography), which shows the anatomy of the vessels and thus whether there is a blockage, rather than just measuring the calcium score. In a CT angiography, the calcium score (Agatston score) is already measured. However, in a CT angiography scan, the amount of radiation given to the patient is higher compared to a CT scan performed only for a calcium score, and it requires the use of a dye called contrast medium, which allows the vessels to be visualized. Ultimately, the decision on which type of CT scan will be more appropriate varies from patient to patient.

Why is atherosclerosis important?

How to Open a Calcified (Hardened) Artery?
Widespread calcifications and associated vascular stenoses on a patient’s CT (virtual) angiogram
Severe calcification in the vessels indicates that cardiovascular disease is more widespread. In patients with a calcium score greater than 400, the risk of a heart attack is approximately 10 times higher than in those with a score of zero (i.e., those with no calcification at all). Calcifications in the left anterior descending (LAD) artery of the heart carry a higher risk than calcifications in other vessels. However, although there is a very strong correlation between the degree of calcification and heart attack or vascular occlusion, this is not true for every case; it is particularly highly dependent on age. As age increases, the probability of detecting calcium in vascular occlusions also increases (let’s not forget that vascular occlusion does not occur solely due to calcification). Specifically, in 6 out of every 10 cases under the age of 40 where vascular occlusion is detected, the calcium score is zero; meaning the vessels are blocked due to fat accumulation alone, without calcification. Conversely, in cases over the age of 60 where vascular occlusion is detected, the calcium score is zero in only 1 out of every 10 cases. On the other hand, there are also cases where, despite calcium accumulation, no significant narrowing has developed in the vessels. Therefore, while the calcium score is important and gives us an idea of potential adverse events, it is not the sole parameter.

How to remove limescale from blood vessels?

Unfortunately, there is currently no treatment available that can clear away existing calcification. However, by increasing the likelihood of plaques remaining stable, the risk of the condition worsening can be reduced. Everyone with coronary artery calcification, whether mild or severe, must first transition to a healthy lifestyle. These are summarized as follows:
How to Open a Calcified (Hardened) Artery?
International scientific guidelines recommend the use of cholesterol medications known as statins in these patients, stating that they ensure the stabilization of plaques—meaning they reduce the risk of a heart attack by decreasing the likelihood of the plaque rupturing.

How can calcified arteries be opened?

Although the calcification in the vessels cannot be cleared away, vessels blocked due to calcification can be opened. If there is a narrowing or occlusion in a calcified vessel severe enough to obstruct blood flow and disrupt the proper functioning of the heart, the vessel must be opened. However, a calcified vessel is one of the most challenging and risky vascular structures in interventional cardiology. This is because a vessel with low calcification is normally relatively flexible and expands when a balloon is inflated. In contrast, in a highly calcified vessel, this hardness may not be overcome by using only a balloon, or the vessel may crack like a fault line and rupture at the moment it opens. Therefore, knowledge, experience, and the use of specialized materials are of great importance in opening a calcified vessel. The specialized materials/devices used to break up calcification are as follows:
  1. High-pressure balloons
  2. Wire-based balloons (Scoring balloons)
  3. Balloons with blades (Cutting balloons)
  4. Drill-like devices (Rotational atherectomy)
  5. Devices that break calcification with sound waves (Shockwave lithotripsy)
How to Open a Calcified (Hardened) Artery?

High-pressure balloons (NC balloons )

In most cases, high-pressure (NC) balloons are the first choice of equipment because they are successful in opening calcified vessels. Under the effect of the inflated balloon, the calcification is pushed outward, and the vessel is opened. These are specialized balloons that can withstand high pressures, such as 20 atm, and thus possess a very hard surface and significant compression force. In recent years, super high-pressure (35 atm) balloons that are much harder have also come into use.

Balloons with wires (Scoring balonlar)

These balloons are also capable of withstanding high pressure. However, they additionally feature thin wires wrapped around their surfaces. Thanks to this design, when the balloon is inflated, the pressure is applied more intensely along the wires to the calcified area they contact, causing the calcium to break. They are more durable and effective than standard (wireless) balloons. However, in tortuous (curvy) vessels, advancing these balloons to the calcified area is more difficult compared to standard balloons.
How to Open a Calcified (Hardened) Artery?
Types of scored balloons

Balloons with knives (Cutting balonlar)

They are similar to wire-based balloons; however, instead of wires, these balloons feature razor-sharp blades. The blades are recessed while the balloon is deflated and emerge to the surface when it is inflated. These blades are sharper than wires but also stiffer. Consequently, while they are highly effective balloons if they can be advanced to the calcified area, it is not always possible to navigate them through particularly tortuous (curvy) vessels due to their lack of flexibility.
How to Open a Calcified (Hardened) Artery?
Types of cutting balloons

Drill-like devices

These devices operate with a logic similar to the machinery used to tunnel through mountains, advancing and grinding down the calcium like a drill. They are typically used in “rock-solid” vessels where high-pressure, wire-based, or cutting balloons have failed or are predicted to be extremely difficult to use. Their disadvantages include being more expensive than balloons and carrying certain risks, such as getting stuck in the vessel, although the probability is low. There is a common misconception among the public that “stents are not necessary” once these devices are used to open the vessels. On the contrary, these devices are not an alternative to stenting; they provide the preparation that makes the stenting procedure possible. After the calcification is broken down with these devices, the vessel is almost always further expanded with high-pressure balloons, and then a stent is placed.

What is atherectomy (vascular shaving)?

Gemini said Atherectomy (vascular shaving) is the medical name for the procedure performed with drill-like devices. The method that advances by rotating on a thin wire is called rotational atherectomy (RotaPro), while the one that rotates in an orbital plane along with its wire is called orbital atherectomy. Rotational atherectomy is not a new method; it has been in use for over 30 years. Orbital atherectomy, on the other hand, is a relatively new method that has come into use over the

Where do the broken calcium particles go?

The calcium particles that are ground up and released into the blood are even smaller than red blood cells, so they do not block the vessels further downstream. These particles pass through the capillaries, travel through the veins, and are eventually captured and trapped by the spleen or the lymph nodes.

Devices that break up calcium deposits with sound waves (IVL: Intravascular lithotripsy)

The use of this device in interventional cardiology has recently begun. It was developed with inspiration from the use of high-frequency sound (shock) waves to break kidney stones. Shock waves are generated from specific points inside a specialized balloon advanced to the calcified area in the vessel. These waves strike the hard calcium on the vessel wall and shatter it, making the vessel wall more flexible (similar to the damage shock waves cause when a bomb explodes). Thus, balloon and stent applications become safely feasible. IVL is not an alternative to stenting; it is a preparation device for the stenting procedure. Among all calcium-breaking methods, this device carries the lowest risk of complications such as vessel perforation. In other words, it is a very safe and effective device. Its disadvantages are its high cost and the fact that, in some cases, the IVL balloon cannot be advanced to the calcified area due to tortuosity or extreme narrowing.

Which method is used to open a calcified artery in which case?

In the opening of calcified vessels, it is not necessary to use every material for every patient. The choice of material is made by taking cost and the risk of complications into account. In most cases, calcification can be broken with high-pressure balloons, and the vessel can be successfully opened. If success is not achieved with these balloons, other methods are adopted step by step. However, sometimes there are cases with such extreme calcification that skipping stages may be required. For example, it might be necessary to switch directly to a drill device without trying any balloons at all. Or, if it is determined that the calcification in the vessel wall is in the outer layer rather than the inner layer, one might switch directly to IVL without using balloons or a drill. Which method should be used for which patient, in which vessel, and at which stage is an academic subject concerning interventional cardiologists whose specialty is high-risk operations; therefore, it is outside the scope of this article, and technical details have been intentionally omitted (See References).

References

  1. Pesarini G, Hellig F, Seth A, et al. Percutaneous coronary intervention for calcified and resistant lesions. EuroIntervention. 2025 Apr 7;21(7):e339-e355.
  2. Barbato E, Gallinoro E, Abdel-Wahab M, et al. Management strategies for heavily calcified coronary stenoses: an EAPCI clinical consensus statement in collaboration with the EURO4C-PCR group. Eur Heart J. 2023 Nov 1;44(41):4340-4356.
  3. Ali ZA, Spratt JC, Finn AV, et al. Identification and treatment of calcified nodules in percutaneous coronary intervention. EuroIntervention. 2025 Dec 1;21(23):e1424-e1433.
  4. Sharma SK, Tomey MI, Teirstein PS, et al. North American expert review of rotational atherectomy. Circ Cardiovasc Interv. 2019 May;12(5):e007448.
  5. Brilakis E. Manual of percutaneous coronary interventions: A step-by-step approach, 1st ed. Philadelphia PA: Elsevier; 2021.