176 Infective endocarditis and bicuspid aortic valve: charactéristics and 1 year outcome

BackgroundBicuspid aortic valve is a common malformation which may de complicated by infective endocarditis (IE). Nethertheless, profile and outcome of infective endocarditis on bicuspid aortic valve is undefined.ObjectivesTo determine clinical and paraclinical characteristics of infective endocarditis on bicuspid aortic valve, and its outcome at 1 year.MethodsBicentric cohort study of 310 IE involved native aortic valves, presenting to Amiens's and Marseille's Hospitals from January 1991 through May 2007.ResultsBicuspid aortic valve were found in 50 patients(16,2%), mean age 45±16 years(p=0,0001),sex ratio 5,25/1. Charlson's comorbidity index was lower in bicuspid valve (1,64±2,56 vs 2,78±2,43; p=0,003). Abscesses was detected in 50% of cases of bicuspid valve vs 19,7% on tricuspid aortic valve (p=0,0001). Previous antibiotic therapy before diagnosis was more frequent in bicuspid IE (30,4 vs 13,7%,p=0,005), as well as negative blood cultures(24 vs 10%,p=0.006). Digestive organisms were significantly less isolated in bicuspid valve. Rate of embolic events was not different.In bicuspid valve IE, surgery was performed in 72% of cases. Peri-operative mortality was 11.1%, Staphylococcus aureus infection was the only independent predictor of peri-operative mortality (HR 34,9; IC95% 1,5-76,8;p=0,024). Uncontrolled infection was the independent predictor of 1 year mortality(HR 20,55 ;IC95% 1,5-268;p=0,021). One year survival of bicuspid valve endocarditis tended to be better compared with that of tricuspid aortic valve(87% vs 77%,p=0,14), but this trend was corrected by age-match(HR 0,656;IC95% 0,38-2,35;p=0,33).ConclusionsEndocarditis of bicuspid aortic valve is frequent in native aortic valve IE, is associated with a younger age, with more annular aortic abscesses, and more use of previous antibiotic therapy before diagnosis. One-year prognosis seems to be no different from tricuspid aortic valve after age-adjustmen