809 A CASE OF CASEOUS MITRAL ANNULUS CALCIFICATION


 Caseous mitral annular calcification (CMAC) is a rare variant of degenerative mitral annular calcification (MAC) with an echocardiographic prevalence of 0.6% of all MACs and an overall prevalence of up to 0.07% in the general population. It primarily affects older patients with hypertension and chronic kidney disease. Due to the general benign prognosis, conservative management of this lesion is recommended in most cases.
 Herein we describe the case of a 78-year-old female patient admitted for sustained ventricular tachycardia treated with Amiodaron infusion followed by electrical cardioversion for hemodynamically instability. Her past medical history was remarkable for hypertension, HFpEF and chronic kidney disease. Trans-thoracic echocardiogram showed the presence of an echo-dense mass with central echo-lucency surrounded by calcifications at the posterior peri-annular and leaflet region of the mitral valve, not associated with valvular disfunction.
 To define the etiology of the arrythmia, a coronary angiography was performed and excluded significant coronary artery disease. Nevertheless, a round-shape hyperdense mass was observed in the left atrium near the atrio-ventricular groove (figure 1): during injection through coronary vessels the contrast was not visible in the lesion. In order to better define the nature of the mass, a Trans-esophageal Echocardiogram was performed and showed a “toothpaste-like” echo-dense mass with central echo-lucency surrounded by a calcified envelope at the posterior peri-annular region of the mitral valve suggestive for CMAC (figure 2); 3D zoom imaging clarified its relationship with P2 scallop of posterior mitral valve leaflet (figure 3). For the best tissue characterization and to definitely exclude other mass-like lesions, such as myxoma, papillary fibroelastoma, myocardial abscess, vegetations, lipomatous hypertrophy, Cardiac Magnetic Resonance was performed and showed low-signal intensity in both T1- and T2-weighted sequences, reflecting its calcium content. First-pass perfusion sequence reveals no contrast enhancement, whereas late gadolinium enhancement depicts a peripheral rim of enhancement confirming our suspect.
 In Conclusion, CMAC is a rare disorder requiring a multimodal imaging approach to differentiate it with other intra-cardiac masses. Its course is generally benign and whether not associated with valvular or hemodynamic significance, it could be considered as a bystander.
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