Endocarditis on the bicuspid aortic valve: what's the risk?

In this issue of Heart , Tribouilly et al ( see page 1723 )1 report on their experience in patients with infective endocarditis of the native aortic valve. Three-hundred and ten patients were recruited prospectively over 16 years, and in the cited study the authors chose to analyse the data from a subset of 50 patients who were shown to have bicuspid aortic valves (BAV). This group was chosen because BAV is the most common congenital cardiac abnormality. The cohort was characterised by being significantly younger than the patients whose aortic valves were trileaflet (TAV), more likely to have received antibiotic therapy prior to the confirmation of a diagnosis of infective endocarditis and had a strikingly higher rate of the specific complication of aortic perivalvular abscess formation. It is generally accepted that infection with Staphyloccocus aureus is associated with a higher risk of abscess formation, and, in almost all of the cases with abscesses in both the BAV and TAV groups, this was the pathogen. However, the relative risk of abscess formation was increased by a factor of two and a half in the BAV group, which is another intriguing and potentially alarming observation. The diagnosis of perivalvular abscess was most commonly detected with transoesophageal echocardiography, the superiority of this technique over the transthoracic (TTE) approach having been demonstrated some years ago.2 The study protocol used by the authors mandated …