Cardiac Blood Tests

Cardiac blood tests can give your provider insight into how well your heart is functioning. Combining this information with your medical history and your family history can help your provider determine your risk of cardiovascular disease. Some tests, like the ones that measure cholesterol, are common. Others are not as well-known.


What are cardiac blood tests?

Cardiac blood tests help your healthcare provider determine your risk of getting heart and blood vessel diseases. Your provider will consider your test results and look at your family history and your own health history to calculate your risk.

There are a number of different blood tests for heart function. They include:

Cholesterol-related tests

  • Total cholesterol.
  • Triglycerides.
  • High-density lipoprotein (HDL or the “good” cholesterol), which eliminates bad cholesterol.
  • Low-density lipoprotein (LDL or the “bad” cholesterol), which can build up in arteries.

Protein-related tests

  • Lipoprotein (a), an additional lipoprotein that is present in some people and increased heart risk.
  • Apolipoprotein B (ApoB), a protein that is included in bad cholesterol.
  • Fibrinogen, a protein in your blood that helps it clot.
  • Aminoterminal, pro-brain natriuretic peptide (NT-proBNP), a protein your heart makes which is increased in heart failure.

Indicators of inflammation, which may play a role in forming plaque

  • Ultra-sensitive C-reactive protein (us-CRP).
  • MPO (myeloperoxidase).

Tests for diabetes, a disease that can harm blood vessels

Tests for substances that increase your cardiovascular risk

  • Homocysteine (an amino acid).
  • Trimethylamine N-oxide (TMAO). Your gut produces this when it breaks food down.


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When is a blood test for heart function performed?

Your healthcare provider will order cardiac blood tests if you have heart disease, high cholesterol and/or high triglycerides or a family history of heart disease. They’ll use this information to figure out how high your risk is for a heart attack, stroke or other cardiovascular problems.

Cholesterol tests are common for everyone, but your provider may only order less common tests if you have multiple risk factors for cardiovascular disease. More information will give your provider a better understanding of your cardiovascular risk.

Who performs cardiac blood tests?

Your primary care provider may order blood tests to check your cholesterol. However, your cardiologist, a provider who specializes in heart care, will most likely be the one who orders blood tests for heart function. You’ll need to go to another provider who can collect a sample of your blood for analysis in a lab.


Test Details

How do I prepare for a blood test for heart function?

If your healthcare provider asks you to fast, don’t eat or drink anything except water for nine to 12 hours before your blood draw appointment. It’s important to drink enough water to stay hydrated, though. This can make it easier for your provider to find your vein and get a blood sample, which makes it more comfortable for you. Many people like to schedule their lab appointment for first thing in the morning because it’s easier to fast while you’re sleeping.

What to expect on the date of the cardiac blood tests

You’ll check in at the medical office or lab that draws blood for testing. Some places require appointments, while others work on a first-come, first-served basis. The person collecting your blood sample may ask you if you’ve been fasting for nine to 12 hours, which means having nothing but water during that time.

Before taking your blood sample

  1. You’ll sit in a chair with an armrest where you can stretch your arm out in front of you.
  2. Roll up your sleeve past your elbow if you’re wearing a long-sleeve shirt.
  3. Your provider will wipe an antiseptic liquid in the bend of your arm (on the other side of your elbow) and put an elastic band around your arm (above your elbow).


What to expect during the cardiac blood tests

Now that your skin is clean and ready, your provider will put a needle into a vein in your arm. This is usually very quick. You’ll feel the needle go into your skin as if someone were sticking a pin in it. Some people find it easier to look away for this part.

The blood will flow into a tube that a lab will receive. Your provider will remove the stretchy band and take the needle out of your arm. Then they’ll put a bandage on the area where the needle went into your skin. It might hurt a little bit in this area.

What to expect after the blood test for heart function

You’re free to go home once your provider places a bandage on your arm. You can go back to eating and drinking normally.

Results and Follow-Up

What type of results do you get and what do the results mean?

Compare your results to these normal numbers:

Ideal ranges for cholesterol-related tests

  • Total cholesterol: 125 to 200 mg/dL.
  • LDL or bad cholesterol: Below 100 mg/dL (below 70 mg/dL if you have diabetes or have a high risk of heart disease).
  • HDL or good cholesterol: Above 40 to 60 mg/dL.
  • Triglycerides: Less than 150 mg/dL.

Ideal levels for protein-related tests

  • Lipoprotein (a): Less than 30 mg/dL.
  • Apolipoprotein B (ApoB), which is in cholesterol: Less than 100 mg/dL.
  • Fibrinogen: Less than 300 mg/dL.
  • Aminoterminal, pro-brain natriuretic peptide (NT-proBNP): Less than 125 pg/mL.

Ideal levels for indicators of inflammation

  • Ultra-sensitive C-reactive protein (us-CRP): Less than 2.0 mg/L.
  • MPO: Less than 350 mg/g.

Ideal levels for diabetes tests

  • Hemoglobin A1c (HgA1c): 5.6 or lower.
  • Fasting glucose: Less than 100 mg/dL.
  • Insulin: 1 to 24 U/ml.

Ideal ranges for other tests

  • Homocysteine (Hcy): Less than 10 umol/L.
  • Trimethylamine N-oxide (TMAO): Less than 6.2 uM.

If your cardiac blood test results aren’t at ideal levels, your healthcare provider may want you to make some changes to your lifestyle, such as:

  • Eating foods that have less fat and avoiding fast food and red meat.
  • Exercising more often.
  • Not using tobacco products.
  • Losing weight.

You may also need to start taking medicines (like medicines to lower your cholesterol, for example) if your provider decides you need them to prevent heart disease.

When should I know the results of the test?

Although lab processing times vary by location, you’ll most likely get your results within a couple of days.

When should I call my doctor?

Contact your provider if you haven’t received results in a week or if you don’t understand what your results mean.

A note from Cleveland Clinic

Modern medicine gives healthcare providers ways to learn about your cardiovascular risks such as with cardiac blood tests. Once they know your risk of heart attack and stroke, they can work with you on a plan to help you. Making healthy changes to how you live can go a long way toward bringing down your risk of heart disease.

Medically Reviewed

Last reviewed on 11/26/2021.

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