NEW YORK (Reuters Health) - Patients with most cardiovascular devices do not need antibiotic prophylaxis before dental procedures, according to new recommendations by the American Heart Association on the evaluation and management of infections related to nonvalvular cardiovascular devices published in the October 21st issue of Circulation.

"Hundreds of thousands of these devices are now placed every year," lead author Dr. Larry M. Baddour told Reuters Health. So even though infections are rare for the most commonly implanted devices, they can be severe and clinicians must consider this possibility when patients present with local or systemic signs of infection.

Because infections are often delayed in onset, the patient is often under the care of a primary care provider by the time they cause symptoms, Dr. Baddour added. Of primary importance in these cases is the need to obtain cultures of blood, drainage material, or percutaneous aspirates of fluid or abscess before initiating treatment with antibiotics.

The AHA's Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, which drafted the recommendations, notes that clinical manifestations resemble those of infective endocarditis or endarteritis, and fever is almost always present. Other manifestations include embolisms, sepsis, and organ dysfunction.

However, less aggressive microorganisms can cause subacute to chronic presentations. Fastidious and rare microorganisms are not commonly associated with nonvalvular device infections.

Ultrasound can be useful in visualizing abnormalities, such as vegetations or effusions, and is the modality recommended for suspected endocarditis, pericarditis, thrombosis and pocket site infections.

Angiography is recommended when aneurysm or pseudoaneurysm associated with stents, patches or vascular grafts is suspected. The value of CT, MRI or plain radiography lies in their ability to identify misplaced or displaced devices.

Perhaps most surprising to clinicians, Dr. Baddour noted, will be the recommendations against secondary prophylaxis for nonvalvular devices. Unlike patients with prosthetic heart valves, these patients should not undergo routine antibiotic treatment prior to dental, respiratory, gastrointestinal or genitourinary procedures.

By contrast, secondary prophylaxis is recommended if incision and drainage of infection is performed or if an infected device is being replaced

"Cardiovascular device infections will continue to present critical clinical challenges that demand vigilance and attention to changing materials, design, and patient characteristics for best outcomes," the committee concludes.

Circulation 2003;108:1822-1830.

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