April 10, 1996
Media Contact: John Cramer
Phone: (410) 955-1534
A Johns Hopkins study establishes the first set of guidelines for diagnosing and treating people with heart-valve infections that cause strokes and other damage to the brain. The guidelines, which use the imaging technique called computerized tomography (CT), may mean more effective and less expensive care of this problem.
Damage to the brain's blood vessels occurs in up to 40 percent of patients with infected heart valves needing replacement, but most patients do well if surgeons first study images of the brain using a CT scanner and resolve the brain problem before operating on the heart valve, according to the study's results. In CT scanning, X-rays are used to produce clear images of thin cross sections of the inside of the body. The study, which confirms the importance of CT scanning in this disorder, is published in the April issue of The Annals of Thoracic Surgery.
These cases are difficult to manage because valve surgery and anti-clotting drugs may worsen the brain injury, says A. Marc Gillinov, M.D., the study's lead author and a Hopkins' cardiac surgery fellow. "How to evaluate and treat these patients remains controversial," says Gillinov. "Recommendations we developed from our study should minimize unnecessary tests and result in good outcomes for most patients."
Researchers reviewed the management of 34 patients who underwent surgery at Hopkins from 1983 to 1995 for endocarditis, an inflammation of the internal lining of the heart and its valves, and who also had brain damage caused by blood clot, bleeding, aneurysm (an abnormal ballooning of an artery), stroke or meningitis. The patients underwent pre-operative brain studies that included CT scanning, magnetic resonance imaging (MRI), cerebral angiography (X-ray studies of blood vessels) and lumbar puncture (removing fluid from the space around the spinal cord). The CT scans found brain injuries in
29 patients, while MRI revealed only one injury missed by CT scanning. The results suggest that routine MRI and cerebral angiogram are unnecessary and costly, and that cerebral angiogram is needed only if CT images show bleeding.
The study recommends that valve surgery only be performed when the brain injury has been resolved and CT scans show no bleeding or fluid build-up in the brain. In addition, in stroke patients valve surgery should be delayed, if possible, for two to three weeks if there is no bleeding and for four weeks if there is bleeding. Also, if a brain aneurysm is caused by an infection, the aneurysm should not be removed before valve surgery. But if it ruptures, it should be removed two to three weeks before valve surgery, according to the guidelines.
"Neurologic problems are common in endocarditis patients," says Gillinov. "Despite this, we found that most do well if surgery can be delayed several weeks, and that the CT scan is the best pre-operative imaging technique."
Endocarditis, which may occur through infected needles, surgery, dental procedures, hemodialysis or acupuncture, is caused by bacteria that invades the blood and infects the lining of the heart and its valves. The clots that form on the valves break off and carry infected tissue to other parts of the body. The infections can block and erode blood vessels in the brain. These brain injuries may be surgically repaired, treated with antibiotics or disappear over time.
Other authors of the study, which was supported by the Johns Hopkins Medical Institutions, were Rinoo v. Shah, M.D., William E. Curtis, M.D., R. Scott Stuart, M.D., Duke E. Cameron, M.D., William A. Baumgartner, M.D. and Peter S. Greene, M.D.