Clinical Lab Tests Measure Heart Disease Risk; Guide Prevention and Treatment

WASHINGTON, March 8, 2013 /PRNewswire-USNewswire/ -- Most of us know about lab tests for high cholesterol and how important they are in helping prevent and control heart disease.  But lab tests do much more—helping physicians prevent heart problems, diagnose heart attacks, and manage heart conditions.

Diagnosing heart attacks

One of the most important roles is helping physicians diagnose heart attacks, even when the symptoms are unclear. Doctors often use a test that measures the enzyme troponin that is released after a myocardial infarction, or heart attack, has occurred.

A troponin test is often the first test that emergency rooms use because the protein appears early, giving physicians a clue to whether a heart attack is occurring.  Troponin stays in the blood for as long as a week, allowing physicians to identify heart attacks and take action to prevent further damage even if the patient was slow to seek medical care.

One study found that testing led to a 50% increase in patients diagnosed with a confirmed heart attack.

"The troponin test can help save lives," said Alan Mertz, President of the American Clinical Laboratory Association (ACLA). "It helps physicians determine whether patients who come to the emergency room with chest pains are really having a heart attack.  If so, patients can get immediate care; if not, they can go home without worry." 

The tests, which cost $25 and $50, may be able to help reduce the $12 billion spent every year on hospitalizing patients who are not actually experiencing heart attacks. 

Doctors also often perform another lab test called myoglobin along with the troponin test to diagnose or rule out a heart attack. Myoglobin is one of the first proteins to be released after a heart attack occurs. 

Predicting Risk of Coronary Disease

Lab tests also can help predict a patient's risk of having a heart attack. A blood test for high sensitivity C-reactive protein (CRP) detects the presence of inflammation that can lead to blockage of arteries. The CRP test, combined with tests for cholesterol and triglycerides, helps doctors evaluate the presence of heart disease. The CRP test costs between $60 and $150, but can be critical in helping avoid heart attack that can cost $28,000.

In one Harvard Women's Health study, CRP was a better predictor of heart attack risk than even cholesterol levels. Women in the study group with the highest CRP levels were four times as likely to have died from coronary disease or to have suffered a nonfatal heart attack or stroke.

People who have high CRP levels are often treated with cholesterol-lowering drugs called statins. One study showed that use of a statin drug in people with high CRP levels --- even though they did not have high levels of the "bad" LDL cholesterol --- led to significant decreases in major cardiovascular events such as heart attacks or stroke.

"Clinical lab tests like the CRP test can identify patients at risk so physicians and patients can take the steps necessary to reduce it," said Mertz.

The American Clinical Laboratory Association is a non-profit group representing the nation's clinical  laboratories. See www.acla.com.  Results for Life, the group's educational campaign, focuses on the value of laboratory medicine. See www.labresultsforlife.org.

Contact: Scott McGoohan, 202-637-9466

SOURCE American Clinical Laboratory Association