Troponin Test

Overview

A protein found in the cardiac muscle is called troponins. Troponin is released into the bloodstream when the heart becomes damaged. To detect if you are having a heart attack, doctors will measure your cardiac troponin levels. Doctors can also use a troponin test to help them find the best treatment.

To detect a heart attack, doctors used previously other blood tests such as the CPK enzymes test. They are not always the best test, as they aren’t sensitive enough for every attack. These blood tests do not detect smaller heart attacks. Other tests can also be used to measure substances not specific enough for the heart muscle.

Troponin is more sensitive. Doctors can diagnose heart attacks and other conditions quicker by measuring cardiac troponin levels in the blood.

What does troponin do?

Troponin proteins help regulate muscle contraction. They are divided into three subunits:

• Troponin C (TnC): It binds with calcium and initiates muscle contractions, and helps to move TnI.
• Troponin I (TnI): It works in conjunction with TnC to pull muscle fibers.
• Troponin T (TnT): It anchors troponin proteins into a separate protein called Tropomyosin.

Troponin tests determine levels of TnI and TnT.

Why Test Is Done?

Troponin is a protein that is found in the heart muscle, but not in the blood. Yet, this protein can be released into the bloodstream if the heart is damaged. A slight increase in troponin levels can indicate damage to the heart. High levels of troponin can indicate a heart attack.

If you are experiencing symptoms of a severe form of heart failure, a troponin test might be recommended. There may be warning signs (e.g., fatigue or tightness in the chest) that occur months before a heart attack. However, one can happen without warning. Heart attacks usually occur suddenly and can get worse quickly.

A silent cardiac attack occurs when a person has a heart attack but does not experience the usual symptoms. This can manifest as a chill, dizziness, or general weakness. A troponin test may be recommended if your healthcare provider suspects that you are having a silent cardiac attack.

When To Get Tested?

Your doctor will recommend this test if you’re experiencing chest pain or related heart attack symptoms, including:

• Arm, shoulder, neck, and back pain.
• Fatigue or weakness
• Intense sweating
• Confusion, dizziness, lightheadedness, or loss of consciousness
• Nausea
• Shortness of breath
• Fatigue
• Lips or skin that is pale or blue
• Heart palpitations are a feeling that your heart beats rapidly
  

Also Read: 4 Blood Tests to Assess Your Heart Health

How To Get Tested?

This test will be performed at the same time that other tests are done to determine the risk of a heart attack. It is not necessary to do anything in preparation.

Your blood troponin test will be performed by a nurse or a pharmacy technician. Your healthcare provider will most likely be present if you are being evaluated for an emergency condition such as a heart attack.

You can also opt for a home visit for blood sample collection for the troponin test.

Before the Test

You may also have additional tests that will help you and your healthcare provider determine if you are suffering from a heart attack. An electrocardiogram (EKG) will be performed. This non-invasive test uses electrodes placed on your chest to measure the electrical activity and any abnormalities that your heart produces as it beats.

A non-invasive pulse oximeter will be used to measure your blood oxygen levels. This small device is worn on the finger.

Your blood oxygen, carbon dioxide, and pH might be measured using an arterial blood gas (ABG). This test does not require a blood sample from your vein.

During the Test

A band will be placed around your arm just above the vein to conduct your troponin test. A needle will then be used to take the blood sample. The needle and band will be removed after a few minutes.

Alternatively, blood could be taken from another vein such as your hand.

If you’re in an emergency room or are a patient at the hospital, an intravenous (IV) line will sometimes be placed into one of your veins to collect blood as needed. This eliminates the need to perform multiple punctures.

After The Test

A bandage will be placed on the site of a needle puncture to perform your troponin test. Your nurse will also check on you regularly to ensure that there is no bleeding.

Test Results

Your troponin test results may be available in a matter of minutes. It can take up to an entire hour depending on where you are located.

The concentration of troponin is measured in nanograms per liter (ng/mL). High-sensitivity tests measure troponin levels as nanograms per Liter (ng/L).

• Normally, troponin should not be detected in the blood.
• Troponin levels between 0.04 and 0.39 ng/ml are often indicative of a problem in the heart.
• Troponin levels above 0.4ng/ml indicate a possible heart attack.

Remember that your laboratory will include normal troponin levels. These values can vary depending on where you are sent.

Troponin C, troponin I, and troponin T are all found in the heart muscle. A cardiac troponin test measures specifically troponin T as well as troponin I.

A high troponin level can indicate a heart attack or damage to the heart muscle. A normal or undetectable troponin level may be repeated if you suspect you are having a heart attack.

Troponin levels can rise within hours after a heart attack and can stay elevated for up to 2 weeks. Your healthcare provider may repeat the test if you have a high troponin level. This can happen within a few hours of a heart attack.

A 2017 study suggested that women might have lower levels of cardiac troponin than men. Women can suffer from heart disease if their levels of cardiac troponin are lower than the “normal” threshold for some labs. Other labs may have different definitions of normal for women and men.

TnI levels above 40ng/L are usually considered high. TnT levels can be considered high if they are higher than 14 ng/L in women and 22 ng/L for men during high-sensitivity testing.

Interpreting Results

Low Or Normal Troponin Levels

Troponin levels in healthy individuals are normal. The chances of heart attack are very less if your troponin levels remain normal even 12 hours after you feel the chest pain.

Troponin Levels That Are Too High

High levels of troponin should be considered a red flag. The more troponin, specifically TnI or TnT, is released into the bloodstream, the greater the risk of developing heart disease. After a heart attack, troponin levels can rise in 3 to 6 hours and can stay high for up to 10 days.

Troponin levels may be elevated acutely or chronically. A healthcare professional can help you determine if you have symptoms that are not related to an increase in troponin levels.

High troponin levels can also be caused by other heart conditions like:

• Myocarditis is an inflammation of the heart muscle.
• Pericarditis is an inflammation of the sac of the heart.
• Endocarditis is an inflammation of the inner heart layer.
• Cardiomyopathy is a condition that causes a weakening of the heart.
• Heart failure
• Stable Angina is a form of chest pain that results from poor blood flow to your heart

High troponin levels could also be caused by:

• Intense exercise
• Medicines, such as Metoprolol, Toprol XL (Lopressor)
• Burns
• Stroke
• Kidney disease
• Diabetes
• Hypothyroidism is an underactive thyroid.
• Pulmonary embolism is a blood clot that occurs in the lungs.
• An extensive infection, like sepsis
• Intestinal bleeding

Final Takeaway

After a heart attack, your body releases troponin into your blood. Troponin levels that are high can indicate other conditions or diseases of the heart.

Call the emergency number immediately if you feel chest pains or suspect that you are having a heart attack. Heart attacks and other conditions that can affect the heart are potentially fatal. All chest pains should be seen by an emergency physician. It is not recommended to self-diagnose.

Lifestyle and treatment changes can improve your heart health, as well as your life quality.

FAQs

• Sources
  • El-Menyar A, Sathian B, Al-Thani H.
    Elevated serum cardiac troponin and mortality in acute pulmonary embolism: Systematic review and meta-analysis. Respir Med. 2019
  • Sandoval Y, Sharain K, Saenger AK, Smith SW, Apple FS, Jaffe AS.
    Clinical use of cardiac troponin for acute cardiac care and emerging opportunities in the outpatient setting. Minerva Med. 2019
  • University of California San Francisco Health.
    Troponin test.
  • American College of Cardiology.
    A brief review of troponin testing for clinicians.
  • University of Rochester Medical Center.
    Health Encyclopedia – Troponin.