American Heart Association Journal Report:
DALLAS, Dec. 22 -- The American Heart Association today issues a new scientific statement that updates the procedures for diagnosing and treating infective endocarditis, a life-threatening heart infection that can be caused by common microbes such as streptococcus or "strep."
The statement by the AHA's Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease is published in today's Circulation: Journal of the American Heart Association.
Infective endocarditis (IE) occurs when bacteria or fungus cause severe infections in the inner lining of the heart or heart valves, leading to tissue damage or destruction. Antibiotics can usually treat the bacterial infections, but if the disease is not detected, the infection can gradually destroy the heart lining or heart valves. Also, clumps of the bacteria can break off and travel through the blood vessels to other organs, including the brain. This can cause serious injury to these organs or even death.
About 20,000-30,000 people develop IE, a disease that represents the fourth leading cause of life-threatening infections such as pneumonia, according to Kathryn A. Taubert, Ph.D., senior scientist in the AHA's department of science and medicine and a co-author of the statement.
Individuals at risk for IE include people with certain defects of the heart present at birth, heart valve disorders, mitral valve prolapse, a history of rheumatic heart disease, or anyone who has an artificial heart valve.
Individuals who are intravenous drug abusers are also at high risk for IE. The statement is the first from the American Heart Association to recommend the set of diagnostic criteria for IE developed by researchers at Duke University Medical Center. The previous diagnostic criteria relied on tests that measured bacteremia (high amounts of bacteria in the blood), regurgitant murmur (a heart abnormality) and blood vessel complications. The new diagnostic strategy includes using a procedure called echocardiography that provides an ultrasound image of the heart to detect infection.
Previous AHA statements provided guidelines for preventing endocarditis and treating the more common forms. The new guidelines, however, include information about treating some of the more unusual causes of IE such as Legionella, a bacteria that can develop in individuals who have prosthetic cardiac valves, or fungal infections such as Candida, Aspergillus, and Pseudomonas that are often found as the cause of IE among intravenous drug users, or in individuals who have central venous catheters.
"The guidelines from Duke work almost like a checklist," Taubert says. "They can help a physician be more certain in the diagnosis because endocarditis can mimic a lot of other diseases, especially in its early stages.
"Although advances in antimicrobial therapy and the development of better diagnostic and surgical techniques have reduced the number of individuals who die from bacterial endocarditis, it remains a life-threatening disease. That's why it is important to recognize and manage the major complications, such as heart failure and infections."
The Duke guidelines offer three categories of diagnosing endocarditis to help physicians manage patients who are affected. The categories include: 1) "definite" cases proven at surgery; 2) "possible" cases, which means there is some evidence of IE, but not as much evidence as a "definite" case; and 3) "rejected" cases, meaning there is a diagnosis other than IE, or the symptoms of the illness resolve after four or more days of antibiotic therapy.
Co-authors are Arnold S. Bayer, M.D.; Ann F. Bolger, M.D.; Walter Wilson, M.D.; James Steckelberg, M.D.; Adolph W. Karchmer, M.D.; Matthew Levison, M.D.; Henry F. Chambers, M.D.; Adnan S. Dajani, M.D.; Michael H. Gewitz, M.D.; Jane W. Newburger, M.D.; Tommy W. Gage, R.Ph., D.D.S., Ph.D.; and Patricia Ferrieri, M.D.
NR 98-4599 (Circ/Taubert)
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at (214) 373-0268. (Please do not publish numbers.)
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