What is a Troponin Test? How is it important in diagnosing a heart attack?

When we suddenly feel a sharp pain in the middle of our chest, a feeling of tightness, or difficulty breathing, we all get scared, right? The first thing that comes to mind is, "Is this a heart attack?" At a time like this, as soon as you are rushed to a hospital, especially the Emergency Department (ETU), the doctors will do several tests to determine your exact condition. Among them, a very important and main blood test is the Troponin test. Although many people have heard of this, they do not know exactly what it does and why it is so important. So today, let's talk about this simply, in a way that you can understand.

Simply put, what is this Troponin test?

Okay, let's understand this this way. Troponin is a special type of protein found inside our heart muscle cells. Think of our heart muscle cells as little houses. Troponin is like the stuff inside those houses. In a normal healthy person, these things, called troponin, are inside the houses. They don't get into the blood. And even if they do, they come in such small amounts that they can't be detected.

However, in a situation like a heart attack, a blood vessel supplying the heart is blocked, and the heart muscle cells do not get the oxygen they need, and those cells start to die. It's like when houses are damaged. What happens when the walls of a house break? The contents inside are thrown out, right? In the same way, when heart muscle cells are damaged, the troponin protein inside them is released into the bloodstream.

A troponin test involves taking a sample of your blood and measuring whether or not there is troponin in it, and if so, how much. The higher the troponin level in your blood, the more damage there is to the heart muscle. This can help doctors understand the severity of a heart attack.

The new troponin tests (high-sensitivity troponin tests) are very sensitive. This means that these tests can detect even very small amounts of troponin in the blood. This has greatly reduced the time it takes to diagnose a heart attack. Also, sometimes even when symptoms are not obvious, and there is no significant change in the ECG, this test can confirm whether or not there is a heart attack.

Are there two types of troponin?

Yes, there are two main types of troponins that are released into the blood when our heart is damaged. Doctors call these by the letters 'I' and 'T'.

• Troponin I (Troponin I or cTnI): This is very special. Because this type of troponin is only found in the heart muscle. It is not found in any other muscle in our body. Therefore, if the level of Troponin I in the blood is elevated, it very clearly indicates that there is damage to the heart muscle. It is like an identification card reserved only for the heart.

• Troponin T (Troponin T or cTnT): This type of troponin T is actually present in small amounts in other muscles in our body (for example, muscles attached to bones). But don't worry. The structure of troponin T in the heart is slightly different from that found elsewhere. Today's tests can only select and measure the cardiac-specific troponin T.

After a heart attack, these troponin levels usually begin to rise rapidly between 3 and 12 hours . They peak at about 24 hours . They remain elevated in the blood for several days after that. Therefore, even if you have chest pain and go to the hospital a day or two later, this test can detect whether you have had a heart attack.

Is this test only done for heart disease?

No. The troponin test is most often used to diagnose a heart attack, but troponin levels can also be elevated in any other condition that can damage the heart muscle. This means that elevated troponin levels do not always mean you have a heart attack. Your doctor will make an accurate diagnosis based on your symptoms and all of your other test results.

Here are some other reasons why troponin levels may be elevated:

• Chronic kidney disease: When the kidneys are not working properly, things like troponin in the body are not properly filtered and removed. Therefore, the troponin level in the blood can simply be high.
• Pulmonary embolism: This is an emergency. This puts a lot of pressure on the heart, causing damage to the heart muscle and the release of troponin.
• Congestive heart failure: When the heart becomes weak and unable to pump enough blood to the body, the heart muscle can continue to be damaged.
• Heart surgery: It is common for some damage to the heart muscle during heart surgery, so troponin levels increase after surgery.
• Heart valve diseases: When the heart valves do not work properly, the heart has to work harder. This can damage the heart muscle over time.
• Arrhythmias: When the heart beats abnormally fast, it can damage the heart muscle.
• Severe infection that has spread throughout the body (Sepsis): In this case, the body's reactions can damage organs including the heart.
• Excessive exercise: Even very strenuous, unbearable exercise can sometimes temporarily increase troponin levels.
• Excessive stress or trauma: Hormonal activity that occurs when you experience unbearable sadness, trauma, or stress can also damage the heart muscle.

How is this test done? What do you need to know?

This is a very simple test. It involves taking a small sample of blood from a vein in your arm. If you already have an IV line, you can take some blood from that. So you don't need to get a needle.

Since this test is usually done in an emergency, there is no need to prepare for it in advance. But there is one very important thing you should know.

If you are taking vitamins or supplements containing vitamin B7, or biotin, you should definitely tell your doctor about it. Some beauty products, especially vitamins for hair, skin, and nail health, contain a lot of biotin. This biotin can affect the results of the troponin test. This means that even if your troponin level is actually high, it may show up as low on the report because of the biotin. Isn't that dangerous? So it's your responsibility to inform your doctor about this.

Usually, doctors don't wait for the troponin report to come in when a heart attack is suspected. They look at the symptoms and the ECG, and start the heart attack medication immediately. Because every second is precious at a time like this. Then, when the troponin report comes in, they change the treatment accordingly, if necessary.

How do I understand the test report?

The report for the troponin test is usually available within an hour or two. Once the results are received, the doctor will explain them to you.

Normally, the level of troponin in the blood of a healthy person is very low, or even undetectable. These values ​​can vary slightly from laboratory to laboratory and depending on the machine used. However, these are generally accepted values.

The `ng/mL` in this report stands for nanograms per milliliter. Think about it, a nanogram is one billionth of a gram. That's an incredibly small amount. This should give you an idea of ​​how small the amount of troponin is in the blood of a healthy person.

If your troponin result is higher than this normal range, it's called "elevated troponin." It means that the heart muscle has been damaged and troponin has accumulated in the blood.

Why repeat the test?

You may have seen your doctor do a troponin test once when you are admitted to the hospital, and then do the test again a few hours later (e.g. 3 hours, 6 hours). They do that for a reason.

• See if the level is rising: If the troponin level is higher in the second report than in the first report ("rising pattern"), this provides strong evidence that a heart attack is occurring.
• Understand the extent of the damage: How high the troponin level rises and how long it remains elevated can give an idea of ​​the severity of the damage.

Troponin I levels remain elevated for about 5-7 days after a heart attack. Troponin T levels can remain elevated for up to 3 weeks.

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