Blood tests for heart disease

By Mayo Clinic Staff

Introduction

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.

Cholesterol test

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.

High-sensitivity C-reactive protein

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.

Dec. 07, 2016 See more In-depth