WESTPORT, CT (Reuters Health) - Although Chlamydia pneumoniae is commonly found in atherosclerotic plaques in the carotid arteries, it does not appear to have any impact on plaque instability, according to researchers at the Imperial College School of Medicine, in London, UK.

The new finding has important implications for the utility of antibiotic therapy in the prevention of atherosclerotic plaque embolization, Dr. N. Carey and colleagues say in the December issue of Stroke: Journal of the American Heart Association.

The investigators examined the presence and consequences of C. pneumoniae in atherosclerotic plaques in 98 patients with symptomatic carotid artery stenosis. Using polymerase chain reaction, they detected pneumoniae in carotid atherectomy specimens from 25.5% of patients--a rate lower than in other studies, but perhaps more specific.

Preoperatively, atheroma embolization was assessed by transcranial Doppler and by CT scans to look for evidence of ipsilateral cerebral infarctions. "There was no significant difference in plaque stability as measured by embolization rates between the chlamydial-positive and -negative specimens," Dr. Carey and colleagues report. Chlamydial status also had no effect on the degree of carotid artery stenosis.

The findings raise questions about the "likely applicability of large-scale antibiotic intervention" in patients with carotid artery disease, the investigators conclude. The new data "support the view that much remains to be established in the area of infectious etiologies for this process."

(From Reuters)