Utility of cardiac magnetic resonance imaging for pre-operatively evaluating the degree of caseous calcification of the mitral annulus infiltration within the left ventricular myocardium: a case report

BACKGROUND: Depending on the degree of infiltration of dry mitral annulus calcification (MAC) into the left ventricular myocardium, calcification removal may cause thinning of the left ventricular wall and increase the risk of post-operative left ventricular rupture. Therefore, the degree of pre-operative infiltration into the left ventricular myocardium should be assessed as accurately as possible. We report a case of caseous calcification of the mitral annulus (CCMA), a subtype of MAC, in an 84-year-old woman; cardiac magnetic resonance imaging (MRI) was useful in assessing the degree of left ventricular infiltration of calcification. CASE SUMMARY: The patient was referred to our hospital for surgery due to respiratory distress and severe mitral insufficiency. Echocardiography revealed a mass under the posterior mitral annulus adjacent to the mitral valve ring, suspected to be a CCMA. Cardiac MRI was performed to assess the risk of left ventricular rupture. Pre-operatively, no valve ring or left ventricular myocardium infiltration was confirmed. Surgical caseous calcification removal and artificial valve implantation within the preserved valve annulus were then performed. The patient had an uneventful post-operative course and was discharged without complications on the 21st post-operative day. DISCUSSION: In this CCMA case, a pre-operative cardiac MRI was useful for evaluating the degree of the valve annulus and left ventricular myocardial involvement and estimating the risk of left ventricular rupture.