Scientists have been trying to develop an antibody against Chlamydia pneumoniae, after research indicated that this bacterium caused an inflammatory response that exacerbated atherosclerosis and PAD.

But data presented at the American Heart Association scientific sessions, was described as 'a compelling argument that C pneumoniae does not play a role in PAD that is modifiable by antibacterial therapy' by lead researcher Dr Michael Jaff, director of vascular medicine at Massachusetts General Hospital in Boston.

For the study, 145 people with PAD were given the anti-chlamydia antibiotic Rifalazil at doses of 25mg weekly for eight weeks. A further 138 patients were given placebo.

Assessment of peak walking time six months later showed Rifalazil was no better than placebo. Previous trials showed similar negative results.

AHA scientific sessions 4-7 November 2007, Orlando, Florida

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