Severe Mitral Annular Calcification: Insights from Multimodality Imaging

During transthoracic echocardiography (TTE), a 77-year-old woman with exertional dyspnea was found to have large, well-defined masses adjacent to the mitral valve (Fig. 1). Spectral Doppler echocardiography revealed a mean transmitral gradient of 7 mmHg, a mitral velocity–time integral of 45 cm, and a pressure half-time of 130 ms. There was moderate mitral regurgitation, although the exact mechanism was unclear on TTE. Transesophageal echocardiography revealed that the posterior mass prevented complete leaflet apposition, resulting in regurgitation (Fig. 2A), whereas the anterior mass was not affecting leaflet motion—so no mitral regurgitation was seen there (Fig. 2B). The echocardiographic appearances seemed to be consistent with mitral annular calcification (MAC), but alternative causes (specifically tumor) were not excluded. Fig. 1 Transthoracic echocar-diograms show large intracardiac echo-bright masses in A) parasternal long-axis and B) apical 4-chamber views. Fig. 2 Transesophageal color-flow Doppler echocardiograms (midesophageal 4-chamber views). A) Mitral regurgitation occurs because the posterior annular mass prevents normal leaflet apposition. B) Mitral regurgitation does not occur, because the anterior annular ... During cardiac magnetic resonance (CMR), cine imaging with balanced steady-state free-precession sequences showed immobile, low-signal masses in the mitral annulus. After intravenous gadolinium contrast administration, first-pass perfusion images revealed no enhancement of the mass, in keeping with an avascular structure. On the early gadolinium-enhancement images, the mass remained hypointense, but the corresponding late gadolinium-enhancement images revealed a rim of circumferential enhancement surrounding a dark central core (Fig. 3A). Non-contrast cardiac computed tomograms showed severe MAC, confirmed the absence of calcification in the valve leaflets and myocardium itself, and also showed a partially calcified rim with a lower attenuation signal located more centrally within the annulus (Fig. 3B). Therefore, both CMR and computed tomographic imaging features were consistent with caseous MAC, a variant of MAC in which the calcium undergoes liquefaction. Decalcification of the mitral annulus is a recognized surgical challenge1; after extensive multidisciplinary discussion, we adopted a conservative management approach, and the patient remained under monitoring. Fig. 3 A) Bright-blood cardiac magnetic resonance image shows a hypointense mass with hyperenhancement in the rim during delayed inversion recovery imaging, 10 minutes after gadolinium contrast administration. B) Cardiac computed tomogram shows the extent of ...