MedWire News: Patients with a condition called infective endocarditis, in which the heart-valves become inflamed due to an infection, are less likely to suffer a stroke if they receive a short course of antibiotic treatment, results of a US study show.

Dr Stuart Dickerman, from the New York University Medical Center, and colleagues explain that patients with infective endocarditis are at increased risk of stroke because the condition can cause a blockage in blood flow to the brain.

To investigate whether antibiotic therapy can reduce the risk of stroke in people with infective endocarditis, the team studied data on 1437 patients with the condition from 28 countries.

In total, 15% of the patients in the study suffered a stroke either before or after antibiotic therapy.

Analysis revealed that the number of participants who experienced a stroke fell significantly after treatment with antibiotics, and continued to fall with increasing length of antibiotic therapy, regardless of the type of infection.

For example, just 3% of patients experienced a stroke after 1 week of therapy, and this rate fell by 65% after the second week of antibiotic treatment.

Writing in the American Heart Journal, Dr Dickerman and colleagues conclude: "The risk of stroke in infective endocarditis falls rapidly and dramatically after the initiation of effective antimicrobial [antibiotic] therapy."

They add that just 1 week of antibiotic therapy may therefore avert the need for stroke-prevention surgery in most people with infective endocarditis.