What is Calcified Plaque?
Calcification of the coronary arteries, or hardening of the arteries due to calcium buildup, is often found when carrying out a percutaneous coronary intervention (PCI). This is a non-surgical procedure where a small mesh tube, known as a stent, is placed in the heart to improve blood flow. Calcified plaque, or hardened areas in the arteries due to calcium, can make it more challenging to successfully conduct a PCI. It can make the delivery and proper expansion of the stent trickier.
When there’s more calcification in the coronary arteries, the procedure complication risks and long-term harmful outcomes increase. These negative results are closely linked with the severity of coronary artery calcification. Thus, it’s crucial to detect and manage calcified plaques early to ensure the success of the procedure and reduce the risk of future complications.
What Causes Calcified Plaque?
Factors that can increase the risk of developing coronary artery calcification, which is the buildup of calcium in your artery walls, include getting older, having diabetes, kidney disease, and smoking. These conditions can raise the chances of developing this heart issue.
Risk Factors and Frequency for Calcified Plaque
About 6 to 20% of all patients who undergo a procedure called PCI (Percutaneous Coronary Intervention) have a serious condition known as severe coronary artery calcification.
Signs and Symptoms of Calcified Plaque
Understanding a patient’s medical history can help identify potential risks tied to increased coronary artery calcification (CAC), a condition where calcium builds up in the arteries of the heart. For patients who have multiple risk factors for CAC and are undergoing a procedure to capture images of the heart’s blood vessels (known as a coronary angiography), doctors should be particularly alert. If necessary, more detailed imaging techniques from within the blood vessels can be used for a better understanding of the condition.
Testing for Calcified Plaque
Severe blockage in the heart’s arteries (known as severe coronary artery calcification) can be identified in several ways. Using imaging methodology, doctors might see “radiopacities” in the arteries even when no contrast dye has been injected yet. Radiopacities are areas that appear white on X-rays or scans because they block the X-rays, indicating that something solid, like calcium, is present. These solid areas need to be visible on both sides of an artery’s wall, be at least 15 mm long, and be included in the target area where a lesion is noted.
Another way to identify severe coronary artery calcification is with a tool called an intravascular ultrasound (IVUS). An IVUS is a specialized ultrasound procedure that provides images from within the arteries. With IVUS, severe coronary artery calcification is defined as the presence of a calcium deposit that covers an arc greater than or equal to 270 degrees on at least one cross-sectional view of the artery.
Traditional angiography (an imaging technique that uses X-rays to view blood vessels) might not show the presence of calcium in the arteries as clearly, hence it might be underrecognized. However, using advanced imaging techniques like IVUS and other methods like Optical Coherence Tomography (OCT) help doctors detect and understand the severity of calcium build-up in the coronary arteries more effectively.
Treatment Options for Calcified Plaque
The treatment for your heart disease, which includes hard calcium deposits or calcified lesions in the arteries (blood vessels of the heart), depends on how severe the calcium buildup is. A scoring system called the “calcium volume index” or “rule of 5’s” helps doctors determine how likely it is that the hardened plaque in your arteries will cause a stent, a small tube inserted to keep an artery open, to not fully expand if they don’t prepare the lesion area beforehand.
If your arteries have a large arc of calcium, more than half of your blood vessel, that is thick (more than 0.5mm) and long (over 5mm), it’s most likely associated with the stent not fully expanding. In this case, your doctor may use a method called atherectomy.
Atherosclerosis with a mild to medium level of calcification can be treated with certain types of balloons that cut, score, or sculpt the plaque in your arteries. These often don’t require atherectomy. But if you have severe calcification, it is most effectively managed using atherectomy before implanting a stent. Atherectomy not only increases the chances of successful stent insertion but it also change the shape of the plaque, which allows the stent to expand properly by increasing the likelihood of the calcium breaking apart. This ensures that the stent expands to its maximum size, reducing the chances of blockage inside the stent or ‘in-stent restenosis’.
Two main methods are used to prepare you for stent placement if you have severe calcification. The older method is rotational atherectomy (RA) that cuts the plaque with a rotating burr, and the more recent one is orbital atherectomy (OA) that uses a diamond-coated crown moving in an orbit shape. Both have been shown to be effective and safe in large clinical trials.
A new approach for preparing severely calcified lesions uses a procedure called intravascular lithotripsy (IVL), which releases sonic pressure waves to break up the hardened plaque. Also, excimer-laser coronary atherectomy (ELCA) can help if your stent is not expanding as much as it should be because it was placed in a heavily calcified plaque. After your doctor places a stent in your calcified artery, they can use imaging techniques to ensure that the stent has expanded properly.
What else can Calcified Plaque be?
Doctors can use certain techniques known as intravascular imaging to study the nature of plaque build-up in the blood vessels. These approaches are especially good at identifying hardened (or ‘calcified’) plaque, and can do this much better than angiography, a different method of looking at vessels.
However, two intravascular methods, IVUS and OCT, may find it difficult to tell the difference between mostly calcified plaque and lipid-rich plaque, because these diseases can often present in diverse ways within the body.
There’s another technique, near-infrared spectroscopy (NIRS), which can identify lipid-rich plaque (a different type of build-up), helping doctors to tell the difference between this and calcified plaque.
Lastly, it’s important to mention that calcium, a key component of calcified plaque, can settle in various structures of the heart, including the arteries that supply the heart, the heart muscle itself, and the surrounding protective layer known as the pericardium.
What to expect with Calcified Plaque
Calcified coronary artery lesions are linked with poor results both during and after percutaneous coronary interventions, which are procedures performed to open up blocked heart arteries. These lesions are hardened build-ups in the heart arteries, which can affect how well the procedure goes.
At the time of percutaneous coronary interventions, calcified lesions can make the delivery of stents more difficult. Stents are small tubes that doctors insert into a blocked passageway to keep it open. They also don’t expand as well in calcified lesions compared to lesions that aren’t calcified.
This stent under-expansion, where the stent doesn’t fully open up, is directly linked with higher rates of restenosis. Restenosis is when a treated artery narrows again, and this is much more likely to occur when the stent doesn’t expand properly due to the hardened lesions.
Possible Complications When Diagnosed with Calcified Plaque
When the coronary artery (the main artery supplying blood to your heart) is hardened due to calcification and goes through a minimally invasive procedure called percutaneous coronary revascularization, it could lead to more complications during the procedure and could result in poor health outcomes in the long run. One common issue that may occur is the under-expansion of the stent, a small, flexible tube that is inserted into the artery to help improve blood flow. This often happens when the plaque buildup in the artery is heavily calcified and is not adequately prepared before the procedure.
Preventing Calcified Plaque
Calcified lesions, or hardened areas in the body tissues, can occur due to several factors. These include getting older, having diabetes, smoking, suffering from peripheral vascular disease which is a circulation disorder, chronic kidney disease, which is long-term damage to the kidneys, and being on hemodialysis, a treatment for kidney failure. It’s important to understand these factors as they increase the chances of developing these hardened lesions.
