High-Sensitivity Troponin Test

• Troponin is a protein found in the body, specifically in heart muscle cells. The three main types of cardiac troponin proteins are I, T, and C.
• During a heart attack, troponin spills into the bloodstream and it is a biomarker that can indicate cardiac injury.
• Troponin testing is what doctors refer to as "cardiac enzymes."
• The main use of testing troponin levels is to diagnose a heart attack.
• The high-sensitivity cardiac troponin test (hs-cTnT) allows for detection of very low levels of troponin T, helping to diagnose heart attacks more quickly.
• Troponin levels may be used to help diagnose other heart-related conditions, for example:
  • Obstructive coronary artery disease (CAD)
  • Stable angina
  • Congestive heart failure (CHF)
  • Cardiomyopathy
• A heart-healthy lifestyle with a nutritious low-fat diet and regular exercise is the best way to prevent heart disease and heart attack.

Troponin is a protein found in the body, most specifically in heart muscle cells. There are three main types of cardiac troponin proteins: I, T, and C.

In a heart attack, blood flow through the coronary arteries (the arteries that supply the heart) is limited or blocked. The heart muscle cells are starved of oxygen, and they start to die. The troponin proteins within those cells spill into the bloodstream and are biomarkers that can indicate cardiac injury. Blood tests for troponin I and T have been developed to measure the levels of troponin proteins when doctors suspect damage to the heart muscle from a heart attack.

Since the first use of troponin testing, several generations of more refined and more reliable tests have been developed and used to help diagnose heart attack more rapidly and accurately.

The high-sensitivity cardiac troponin test (hs-cTnT) is the latest generation of the cardiac enzyme testing that allows for detection of very low levels of troponin T, helping to diagnose heart attacks more quickly. If the test is negative, it can also help “rule out” heart damage from coronary artery disease (CAD).

When a doctor suspect that a person is having a heart attack or heart muscle damage, they will order a blood test to check for troponin (along with other standard diagnostic tests for patients with chest pain such as EKG, chest X-ray, complete blood count, and blood chemistries). An elevated level of troponin T on the high-sensitivity cardiac troponin test indicates heart muscle damage or a heart attack.

The high-sensitivity cardiac troponin test can detect very small levels of troponin T in the bloodstream. The normal range (value) for high-sensitivity cardiac troponin T test (hs-cTnT) is 14 ng/l. This cutoff for the “normal” level of troponin T was determined by looking at several studies of patients who were “apparently healthy” (no heart complaints) and had this level of troponin T in the bloodstream as a baseline. Thus, when the high-sensitivity cardiac troponin T test detects levels above 14 ng/l, heart damage or heart attack is likely. As the high-sensitivity cardiac troponin T test becomes more widely used, further refinement in the cutoff levels for normal troponin T is expected based on patient’s age, sex, underlying medical conditions, and ethnicity.

If your troponin levels are being measured this means doctors are performing the test to diagnose heart problems that you have.

If troponin levels are high (elevated above normal) and the EKG indicates an acute heart attack, you may have cardiac intervention such as a catheterization with angioplasty and possibly stents, or an evaluation for coronary artery bypass graft (CABG) surgery may be required.

If troponin levels are high and your EKG does not indicate an acute heart attack, the doctor will perform more testing to figure out the reason for your elevated troponin levels. This may include:

• Cardiac catheterization
• Stents
• Cardiac echocardiograms
• Stress testing
• CT (CAT) scan

The main use of testing troponin levels is to help rapidly diagnose acute myocardial infarction (MI), or heart attack. Troponin is a protein very specific for the heart muscle, and when a heart attack occurs, troponin levels in the blood begin to rise within 2 to 4 hours of onset, and continue to be elevated for about 2 weeks. Troponin testing is what doctors refer to as “cardiac enzymes,” and they are frequently measured by a blood test when patients complain of chest pain or symptoms that could indicate heart problems.

Troponin levels can also be used to help diagnose other heart-related conditions, such as:

1. Obstructive coronary artery disease (CAD)
2. Stable angina
3. Congestive heart failure (CHF)
4. Cardiomyopathy

Even though the high-sensitivity cardiac troponin T test is highly indicative of heart muscle damage or heart attack, there are a few other medical conditions that can cause slight elevations in troponin levels, for example:

1. Renal (kidney) failure
2. Chronic heart failure
3. Sepsis (severe blood infection)
4. Pulmonary embolism
5. Myocarditis
6. Aortic dissection
7. Cardiotoxic chemotherapy
8. Blunt chest trauma
9. Strenuous exercise (such as endurance athletes)

• A heart-healthy lifestyle with a nutritious low-fat diet and regular exercise is the best way to prevent heart disease and heart attack.
• In addition to diet and exercise, maintain a healthy weight, don’t smoke, limit alcohol intake, practice stress reduction, manage blood pressure and diabetes, and take any medications as directed. Talk to your doctor about your risk factors for heart disease such as family history, other medical conditions, and cholesterol levels.

Chest pain is a serious symptom that could indicate a heart attack and time is of the essence to get prompt treatment. If you have chest pain or suspect you are having a heart attack call 911 immediately.