What Level of Troponin Indicates Heart Attack?

Troponin Test in Heart Attack: Normal vs. Dangerous Levels

Troponin is a protein present in the heart muscle. When the heart is damaged, troponin leaks into the bloodstream. Doctors measure troponin levels to check if someone has had a heart attack. Read on to discover what level of troponin indicates a heart attack.

What is a Troponin?

Troponin helps the muscles, including the heart, contract and work properly. Generally, levels of troponin remain very low, even undetectable. When a person has a heart attack, their troponin levels rise drastically. There are two main types of troponin that doctors test for:

• Troponin I
• Troponin T

The above-mentioned proteins are specific to the heart muscle. Hence, a rise in either is indicative of heart injury.

What Level Suggests a Heart Attack?

A heart attack causes a sharp rise in troponin levels. In hospitals, doctors use a high-sensitivity troponin test to detect small changes in troponin. In some countries, the threshold for concern is above 99% of the normal range. The exact number differs depending on the lab and the type of test used. However, a typical cut-off might be:

• Troponin I <20 ng/L (in men) and < 15 ng/L (in women)
• Troponin T < 15 ng/L (in men) and < 10 ng/L (in women)

If your troponin levels are higher than that, the doctors will examine other signs like chest pain, ECG results and a medical history to decide if an individual has had a heart attack.

Other Factors That Contribute to High Troponin Levels

While higher levels of troponin indicate a heart attack, they can also rise for other reasons as well, like:

• Kidney Disease : The kidneys help to clear troponin from the blood. If the kidneys are not working well, then that can lead to a rise in troponin levels.
• Heart Failure : In this situation, the heart faces damage and fails to pump blood properly. It leads to a slow and steady rise in troponin levels.
• Irregular Heart Rhythms : Conditions like atrial fibrillation and very fast rates strain the heart. It leads to small injuries in the heart muscle.
• Sepsis : It is a life-threatening reaction to infection and has the capacity to damage the whole body, including the heart. As a result, the troponin level rises.
• Extreme Physical Stress : Doing exercise like running a marathon or any other kind of intense physical labour can also lead to a temporary rise in troponin levels.
• Stroke or brain Injury : Causes neurogenic heart damage lead to a rise in troponin levels.
• Chemotherapy : Cardiotoxic drugs like anthracyclines lead to a rise in troponin levels.

It is the reason why doctors do not rely on troponin alone. They check other symptoms and conduct necessary tests and scans, along with monitoring changes in levels of troponin over time. During a heart attack, the troponin generally rises quickly and keeps elevating for several hours afterwards.

What Happens When Troponin is High?

When troponin levels are high, it indicates damage to the heart. Doctors take this seriously, as a raised troponin level frequently points to a heart attack. They conduct additional tests on the patient, like an ECG (electrocardiogram), blood tests and a heart scan. It helps to confirm whether the heart muscle is injured and why. If a heart attack is suspected, then doctors take quick action. The patient is provided with an oxygen supply, blood thinners and pain relief. In some cases, surgery is also performed to open blocked arteries.

A high troponin level indicates the heart is under strain, but it does not always mean a heart attack. However, the key is to treat them quickly and protect the heart from any future harm.