Big mitral annular calcification: a case report of a dynamic liquefaction necrosis as a potential source of embolism.

BACKGROUND: Mitral annular calcification (MAC) is a degenerative, mostly asymptomatic abnormality usually in elderly patients. Caseous MAC (cMAC) is a rare form with central liquefaction necrosis, which typically involves the posterior annulus of the mitral valve and can cause serious sequelae. However, optimal management of patients with cMAC is not clearly defined.

CASE SUMMARY: In a 71-year-old female patient, MAC was incidentally detected. Tissue characterization with cardiac magnetic resonance (CMR) revealed a cMAC and a conservative approach was chosen. Six months after cMAC diagnosis, the patient developed an acute hemi-occlusion of a retinal artery with cholesterol embolism. At this time, CMR showed a liquefied cavity of the cMAC. Except for atherosclerotic plaques in the aorta and carotid arteries, further stroke work-up was negative. Therefore, the conservative approach was continued. During follow-up, the liquefied cavity regressed completely after another 6 months and the patient was free from further events (total follow-up 3 years since diagnosis of cMAC).

DISCUSSION: A clear diagnosis and quantitative assessment of dynamic processes, such as cMAC, are made possible by performing CMR with multi-parametric tissue characterization. Dynamic changes in cMAC may have serious clinical implications, such as mitral regurgitation or systemic embolization. Among cardiac tumours, thrombus and abscess, cMAC should be included in the differential diagnosis of an intracardiac mass of the posterior mitral annulus in order to avoid further inappropriate diagnostic interventions.