SUNDAY, Oct. 6, 2002 (HealthDayNews) -- A simple blood test in the emergency room can make quick work of diagnosing heart failure.
People coming to the hospital complaining of shortness of breath could be suffering from any number of illnesses, including asthma, pneumonia, panic attacks, or heart failure. Traditionally, doctors have relied on a combination of physical exams, patient histories, chest X-rays and echocardiograms to identify heart failure, a process that can take hours and sometimes requires admission to the hospital.
However, a new blood test can spot a hormone present in elevated levels during heart failure, which means doctors can pinpoint who's suffering from heart disease, how sick they are and what treatment they need immediately. Equally important, they can find out who isn't suffering from heart failure, and go on to correctly diagnose what brought them to the emergency room.
"The presence and level of the hormone gives you a precise measure of how high the risk is for heart failure," says San Diego cardiologist Dr. Alan S. Maisel, who was instrumental in developing the test. "Conversely, if the level of hormone is not high, the chance of heart failure is only 1 or 2 percent."
The blood test, which takes about 15 minutes to administer and read, records the levels of the hormone B-type natriuretic peptide (BNP) in the blood. A low level means the heart is working well. But an elevated level is proof the patient has heart trouble because the body releases the hormone when the heart is not pumping properly.
The inability of the heart to pump blood throughout the body is called congestive heart failure. Among adults over age 65, heart failure is the number one reason for hospital admissions, according to the American Heart Association.
The test received U.S. Food and Drug Administration (FDA) approval in November of 2000, and is now in use in almost 700 hospital emergency rooms across the country, says Nadine Padilla, a spokeswoman for Biosite Inc., the San Diego company that markets the test.
In July, the test received FDA approval for diagnosing other cardiovascular problems, says Maisel, a consultant for Biosite who received funding from the company for his research.
In the emergency room of New Jersey's Hackensack University Medical Center, the BNP test has been used for six months as a part of the work-up for patients reporting a shortness of breath, and the results have been encouraging, says Dr. Joseph Feldman, vice chairman of emergency medicine.
Many elderly patients who come to the emergency room with shortness of breath have both chronic lung disease and heart disease, he says, "and this test is very good at differentiating the diagnoses."
"While six months is too soon to tell if it's greatly improved the diagnoses' accuracy, in many cases it's helped us," Feldman says. "We like it very much."
A study of the BNP test among 1,600 emergency room patients in seven hospitals found doctors using it had an 84 percent degree of accuracy in diagnosing who had congestive heart failure, compared to a 74 percent accuracy rate when using the traditional methods, Maisel says. If you add the blood test to the other diagnostic methods, the accuracy of the diagnosis jumps to more than 90 percent.
"It helps prevent the wrong diagnosis, as well as over-diagnosis of congestive heart failure," he says. "It also shows the risk level for heart failure, and helps doctors target how much treatment to give."
What To Do
For more information about the BNP test, you can visit the American Association for Clinical Chemistry. The American Heart Association has a thorough explanation of congestive heart failure.
