By Mayo Clinic Staff

Your blood offers many clues about your heart health. For example, high levels of "bad" cholesterol in your blood can be a sign that you're at increased risk of having a heart attack. And other substances in your blood can help your doctor determine if you have heart failure or are at risk of developing plaque deposits in your arteries (atherosclerosis).

It's important to remember that one blood test alone doesn't determine your risk of heart disease. The most important risk factors for heart disease are smoking, high blood pressure, high cholesterol and diabetes.

Here's a look at some blood tests you may have to diagnosis and manage heart disease.

A cholesterol test, also called a lipid panel or lipid profile, measures the fats (lipids) in your blood. The measurements can indicate your risk of having a heart attack or other heart disease. The test typically includes measurements of:

  • Total cholesterol. This is a sum of your blood's cholesterol content. A high level can put you at increased risk of heart disease. Ideally, your total cholesterol should be below 200 milligrams per deciliter (mg/dL) or 5.2 millimoles per liter (mmol/L).
  • Low-density lipoprotein (LDL) cholesterol. This is sometimes called the "bad" cholesterol. Too much of it in your blood causes the accumulation of fatty deposits (plaques) in your arteries (atherosclerosis), which reduces blood flow. These plaque deposits sometimes rupture and lead to major heart and vascular problems.

    Your LDL cholesterol level should be less than 130 mg/dL (3.4 mmol/L). Desirable levels are under 100 mg/dL (2.6 mmol/L), especially if you have diabetes or a history of heart attacks, heart stents, heart bypass surgery, or other heart or vascular conditions.

  • High-density lipoprotein (HDL) cholesterol. This is sometimes called the "good" cholesterol because it helps carry away LDL cholesterol, keeping arteries open and your blood flowing more freely. Ideally, your HDL cholesterol level should be over 40 mg/dL (1.0 mmol/L) for a man, and over 50 mg/dL (1.3 mg/dL) for a woman.
  • Triglycerides. Triglycerides are another type of fat in the blood. High triglyceride levels usually mean you regularly eat more calories than you burn. High levels can increase your risk of heart disease. Ideally, your triglyceride level should be less than 150 mg/dL (1.7 mmol/L). The American Heart Association (AHA) states that a triglyceride level of 100 mg/dL (1.1 mmol/L) or lower is considered "optimal."
  • Non-HDL cholesterol. Non-high density lipoprotein cholesterol is the difference between total cholesterol and high-density lipoprotein cholesterol (HDL-C). Non-HDL-C includes cholesterol in lipoprotein particles that are involved in hardening of the arteries (atherosclerosis). This includes low-density lipoprotein (LDL), lipoprotein (a), intermediate-density lipoprotein and very-low-density lipoprotein.

    Non-HDL-C fraction may be a better marker of risk than LDL cholesterol.

C-reactive protein (CRP) is a protein your liver produces as part of your body's response to injury or infection (inflammatory response).

CRP is a sign of inflammation somewhere in the body. However, high-sensitivity CRP (hs-CRP) tests can't pinpoint where in the body this may be happening or why it's happening. Inflammation plays a central role in the process of atherosclerosis, in which fatty deposits clog your arteries.

Measuring CRP alone won't tell your doctor your risk of heart disease. But factoring in hs-CRP test results with other blood test results and risk factors for heart disease helps create an overall picture of your heart health.

Because there's variability in CRP levels, the test should be done twice, two weeks apart. An hs-CRP level above 2.0 milligrams per liter indicates a higher risk of heart disease.

This test screening isn't currently recommended for people without symptoms or a known risk of heart disease.

Cholesterol-lowering statin medications may reduce CRP levels and decrease your heart disease risk.

Lipoprotein (a), or Lp(a), is a type of LDL cholesterol. Your Lp(a) level is determined by your genes and isn't generally affected by lifestyle.

High levels of Lp(a) may be a sign of increased risk of heart disease, though it's not clear how much risk. Your doctor might order an Lp(a) test if you already have atherosclerosis or heart disease but appear to have otherwise normal cholesterol levels.

Lp(a) is often tested if you have a family history of early-onset heart disease or sudden death.

Drugs are in development to lower Lp(a), but it isn't yet clear what effect lowering Lp(a) will have on heart disease risk. People with high Lp(a) are generally advised to keep a low LDL cholesterol level.

This new test measures levels of ceramides in the blood. Ceramides are produced by all cells and play a significant role in the growth, function and ultimately death of many types of tissue. Ceramides are transported through the blood by lipoproteins and are associated with atherosclerosis.

Three specific ceramides have been linked to plaque buildup in the arteries and insulin resistance. Elevated levels of these ceramides in the blood indicates a higher risk of cardiovascular disease within one to five years.

Brain natriuretic peptide, also called B-type natriuretic peptide (BNP), is a protein that your heart and blood vessels produce. BNP helps your body eliminate fluids, relaxes blood vessels and funnels sodium into your urine.

When your heart is damaged, your body secretes high levels of BNP into your bloodstream to try to ease the strain on your heart. BNP levels may also rise if you have new or increasing chest pain (unstable angina) or after a heart attack.

Your BNP level can help in the diagnosis and evaluation of heart failure and other heart conditions. Normal levels vary according to age and gender and whether you are overweight. One of the most important uses of BNP is to try to sort out whether shortness of breath is due to heart failure.

For people who have heart failure, establishing a baseline BNP can be helpful and future tests can be used to help gauge how well your treatment works. A variation of BNP called N-terminal BNP also is useful in diagnosing heart failure and in some laboratories is used instead of BNP. N-terminal BNP may also be useful in evaluating your risk of a heart attack and other problems if you already have heart disease.

A high level of BNP alone isn't enough to diagnose a heart problem. Your doctor will also consider your risk factors and other blood test results.

Dec. 07, 2016