Abstract 15426: Comparison of Multimodality Imaging in Mitral Leaflet Lengths in Patients Undergoing Surgical Myectomy: A Prospective Study in Hypertrophic Obstructive Cardiomyopathy Patients

Abstract

Introduction: In hypertrophic obstructive cardiomyopathy (HOCM), mitral valve (MV) leaflets in often contribute to left ventricular outflow tract obstruction (LVOTO). Hence, MV assessment is crucial during surgical planning. 2 or 3-dimensional transesophageal echocardiography (2D or 3D TEE) & cardiac magnetic resonance (CMR) are used to measure MV length. Hypothesis: We sought to compare MV leaflet lengths using intraoperative TEE [2D, zoom 3D, automatic quantification of mitral valve (AMVQ)], & preoperative CMR. Methods: We prospectively studied 50 HOCM patients (59±12 years, 46% men, basal septum 18±5 mm, LVOT gradient 87 ±56 mmHg) undergoing surgical relief of LVOTO. We compared MV leaflet length on a) long-axis 2DTEE b) 3DTEE using multiplanar reconstruction c) AMVQ, EchoPAC, General Electric & d) CMR. Results: Mean anterior leaflet lengths (mm) were as follows: 2D TEE (3.3 ±0.3), 3DTEE (2.9±0.5), CMR (3.1±0.4), & AMVQ (2.9±0.5). Mean posterior leaflet lengths were 1.7±0.3, 1.7±0.4, & 1.7±0.2 & 1.9±0.4 mm, respectively. Assuming 3DTEE as the gold standard, the closest correlation for anterior leaflet was with CMR (average overestimation by CMR of 0.5 mm [root mean square deviation or RMSE% 17]), intermediate correlation with 2DTEE (average deviation of 0.6 mm [RMSE%:21]) & no correlation with AMVQ (deviation of 0.7mm [RMSE% 24]), Fig 1A-C & 2A-C. No correlation was found for posterior leaflet,Fig 1D-F & 2D-F. Conclusions: There are significant differences in measuring MV lengths using different imaging techniques. In HOCM patients undergoing surgery, precise measurement of MV leaflet lengths is crucial & extrapolation from one technique to other is not recommended.