Abstract 14823: Comparison of a Novel Computed Tomography-Based Assessment of Mitral Annular Calcification to Transthoracic Echocardiogram

Abstract

Introduction: Mitral annular calcification (MAC) is associated with increased stroke and death. The typical assessment by transthoracic echocardiography (TTE) is qualitative visual rating (VR), but this technique is user-dependent and lacks a gold standard for grading. Computed tomography (CT) has high sensitivity for calcium and can quantify MAC. The purpose of this study is to standardize grading of MAC and compare TTE-based assessment of MAC with CT. Methods: The analysis included 60 patients with non-contrast CT and TTE prior to aortic valve replacement or mitral valve (MV) repair. MAC was assessed on TTE by VR (none, mild, moderate, severe), a previously described echo calcium score (ECS), and systematic MAC grading (SMAC). TTE-based MV parameters were recorded. CT data were measured for calcium volume (MACV) via proprietary software (Visage Imaging) by an independent rater with 3D regions of interest in the MV area. Results: Mean age was 77 ± 11; 42% of patients were female. MACV for tertile-based groups (lowest, middle, highest) are shown in the Table. CT detected MAC in a notable portion of patients without MAC by TTE-derived methods: in 16 of 29 patients (55%) by VR, in 5 out of 15 (33%) by ECS, and in 5 out of 16 (31%) by SMAC. Fifteen of 22 patients (68%) with mild MAC by VR had middle or high-tertile MAC on CT. MACV-derived categories reclassified 65%, 60%, and 54% of patients compared with VR, ECS, and SMAC grading by TTE, respectively. Differences were also found across MACV categories for MV velocity, transmitral gradient, and E/e’. Except E/e’, trends were independent of TTE-based MAC analysis and significant after adjusting for mitral regurgitation or stenosis. Conclusions: TTE has limited ability to detect mild MAC compared with CT. This novel CT-based volumetric MAC assessment is feasible and can improve standardized quantification and sensitivity to detect MAC at lower values. Higher MACV by CT was associated with increasingly abnormal MV flow and diastology.