Mitral valve leaflet length as an important factor to differentiate hypertrophic cardiomyopathy from other causes of left ventricular hypertrophy

Abstract

Left ventricular hypertrophy (LVH) with Left ventricular maximal thickness (LVMT) ≥15 mm as a current criteria to differentiate hypertrophic cardiomyopathy (HCM) from other causes of LVH lacks specificity. The recent findings of intrinsic mitral valve leaflet elongation in HCM may potentially distinguish HCM from other causes of LVH. We aim to studying the performance of mitral valve leaflet length in differential diagnosis of HCM from other diseases with LVH. Contrast-enhanced cardiac magnetic resonance was performed following a standard protocol in 291 subjects (grouped by 112 HCM patients; 89 patients with LVH secondary to hypertension, cardiac amyloidosis or aortic stenosis; and 90 controls). Differences in anterior and posterior mitral leaflet length (AML and PML) (mm) among groups were analyzed, as were the diagnostic performance of AML or PML in distinguishing HCM from non HCM LVH. AML and PML in HCM group were longest among the three groups (AML: HCM 26.49 ± 4.28 vs. non HCM LVH 21.98 ± 3.57 VS. normal 21.10 ± 3.12, p < 0.001; PML: HCM 13.57 ± 3.12 vs. non HCM LVH 11.47 ± 2.35 vs. normal 11.72 ± 2.89, p < 0.001). Furthermore, AML and PML were elongating only in HCM regardless of division by LVMT(<15 mm and ≥15 mm) or hypertrophic pattern (symmetric and asymmetric) (p < 0.05). Multiple logistic regression analysis showed AML, PML and LVMT were predictors to differentiate HCM from non HCM LVH with LVMT≥15 mm (p < 0.05). When performed ROC, LVMT>21 mm was proved an optimal cutoff value to differentiate HCM from non HCM LVH with LVMT≥15 mm (AUC 0.779 [95%CI 0.708-0.839]; sensitivity 61.6%, specificity 85.71%). In patients with LVMT between 15 mm and 21 mm, AML> 24 mm and PML>13 mm showed similarly favorable differential diagnosis value between HCM and non HCM LVH by ROC curves (AML: AUC 0.761 [95%CI 0.660-0.844], sensitivity 67.4%, specificity 81.2%; PML: AUC 0.737 [95%CI 0.634-0.823]; sensitivity 51.2%, specificity 89.6%). Elongation of mitral leaflet length in HCM is a specific and intrinsic characteristic and it has a favorable differential value to discriminate HCM from non HCM diseases. Affiliations Cardiology Department, West China Hospital, Chengdu, China Yong Luo , Dan Yang , Hong Liu , Ke Wan & Yucheng Chen Radiology Department, Westchina Hospital, Chengdu, China Jiayu Sun Siemens MR Northeastern Collaboration, Beijing, China Tianjing Zhang Authors Search for Yong Luo in: PubMed • Google Scholar Search for Dan Yang in: PubMed • Google Scholar Search for Hong Liu in: PubMed • Google Scholar Search for Ke Wan in: PubMed • Google Scholar Search for Jiayu Sun in: PubMed • Google Scholar Search for Tianjing Zhang in: PubMed • Google Scholar Search for Yucheng Chen in: PubMed • Google Scholar Corresponding author Correspondence to Yong Luo. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Reprints and Permissions