Infective Endocarditis Prophylaxis May Benefit Bicuspid Aortic Valve, Mitral Valve Prolapse

Infective endocarditis in patients with concurrent bicuspid aortic valve or mitral valve prolapse was associated with higher rates of viridans group streptococci and had a clinical course similar to that of high-risk patients, according to a recent study published in the Journal of the American College of Cardiology.

Patients treated for infective endocarditis in 31 hospitals in Spain were classified as either high risk (indication for infective endocarditis antibiotic prophylaxis), low/moderate risk (no indication for infective endocarditis antibiotic prophylaxis), and infective endocarditis with either concurrent bicuspid aortic valve or mitral valve prolapse. Clinical, echocardiographic, and microbiologic features and adverse events of patients with bicuspid aortic valve or mitral valve prolapse were compared with patients in both the low/moderate- and high-risk groups.

Of the 3208 patients enrolled in the study, 54 had bicuspid aortic valve and 89 had mitral valve prolapse. A total of 1226 patients were considered high risk and 1839 were considered low/moderate risk with no indication for infective endocarditis antibiotic prophylaxis. In patients with mitral valve prolapse or bicuspid aortic valve, the most common cause of infective endocarditis was organisms originating in the oral cavity, mainly viridans group streptococci.

Intracardiac complications and heart failure were common in both groups. When compared with the high-or low/moderate-risk groups, patients with bicuspid aortic valve or mitral valve prolapse had a clinical course closer resembling the high-risk group.

The study authors wrote, “[T]he analysis of the clinical characteristics in [bicuspid aortic valve] and [mitral valve prolapse] patients with [infective endocarditis] revealed an aggressive clinical course with a similar proportion of [infective endocarditis] complications to that of [infective endocarditis] patients with high-risk cardiac conditions, and more intracardiac complications than in patients of the low-risk and intermediate-risk groups.”

They also considered the oral origin of the causal organisms noteworthy, adding, “Overall, our findings open the debate to consider [infective endocarditis antibiotic prophylaxis] before dental procedures not only in high-risk cardiac conditions, but also in patients with [bicuspid aortic valve] and [mitral valve prolapse].”

Reference

Zegri-Reiriz I, Alarcón A, Muñoz P, et al. Infective endocarditis in patients with bicuspid aortic valve or mitral valve prolapse. J Am Coll Cardiol. 2018;71(24):2731-2740.