Bacterial endocarditis complicating mitral annular calcification: a clinical and echocardiographic study

Abstract

Background and aim of the study: Although described in a number of necropsy studies, endocarditis on mitral annular calcification (MAC) has rarely been reported during life. The study aim was to assess the frequency and specific features of bacterial endocarditis complicating MAC.

Methods: Data relating to 62 cases of infective endocarditis of the native mitral valve diagnosed with multiplane transesophageal echocardiography (TEE) over a five-year period were collected prospectively.

Results: Among 62 patients, 15 (24%) had vegetations originating from a calcified mitral annulus (group 1), while 47 had classic leaflet endocarditis (group 2). Group 1 patients differed significantly from group 2 patients with regard to: (i) higher incidence of diabetes mellitus and cancers; (ii) initial clinical presentation, with febrile coma or meningoencephalitis in 53% of cases; (iii) echocardiographic features, with significantly greater vegetations, presence of calcium-dense echoes within the vegetation, high frequency of ring abscess, and high frequency of para-annular ventriculoatrial leakage; and (iv) poorer clinical outcome, with 53% in-hospital mortality.

Conclusion: MAC appears to be an underestimated predisposing factor for a particularly severe type of bacterial endocarditis. The use of multiplane TEE should improve current knowledge of this disease.