Mitral Geometry on the Mechanism of Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy

Xiaopei Lin; Wei Li; Wei Liu; Di Wang; Tingting Sun; Fan Zhang; Ceng Wang; Jing Wang; Jian Zhang; Xiaoying Mi; Weidong Ge; Shuwei Wang; Zhifang Liu; Meijuan Yan; Bing Zhou; Yong Cui; Zhenzhen Wang

doi:10.1016/j.echo.2024.05.002

Mitral Geometry on the Mechanism of Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy

J Am Soc Echocardiogr. 2024 May 14:S0894-7317(24)00224-4. doi: 10.1016/j.echo.2024.05.002. Online ahead of print.

Authors

Xiaopei Lin¹, Wei Li², Wei Liu², Di Wang², Tingting Sun², Fan Zhang², Ceng Wang², Jing Wang², Jian Zhang², Xiaoying Mi², Weidong Ge², Shuwei Wang³, Zhifang Liu³, Meijuan Yan⁴, Bing Zhou³, Yong Cui³, Zhenzhen Wang⁵

Affiliations

¹ Cardiovascular Center, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Jinzhou Medical University Graduate Training Base, Hangzhou, Zhejiang, China.
² Cardiovascular Center, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China.
³ Cardiovascular Center, Department of Cardiothoracic Surgery, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China.
⁴ Rehabilitation Medicine Center, Department of Anesthesiology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China.
⁵ Cardiovascular Center, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China. Electronic address: welcomezhen126@126.com.

PMID: 38754749
DOI: 10.1016/j.echo.2024.05.002

Abstract

Objective: The mechanism of left ventricular outflow tract obstruction (LVOTO) is complex in hypertrophic cardiomyopathy (HCM). We aimed to evaluate the impact of mitral valve geometry on LVOTO by echocardiography.

Materials and methods: The study population comprised 177 consecutive patients with HCM. Morphological findings of left ventricular hypertrophy and LVOTO-related abnormalities were assessed by comprehensive transthoracic echocardiography. Aorto-mitral angle, mitral leaflet length, and coaptation height were measured and analyzed at rest. Multivariable stepwise forward logistic regression analysis was performed to identify geometric predictors of LVOTO.

Results: One hundred and thirty-seven patients had an LVOT gradient ≥ 30 mmHg. Multivariable logistic regression showed that aorto-mitral angle (OR 0.89, 95%CI 0.83-0.95, P<0.001), coaptation height (OR 1.96, 95%CI 1.41-2.72, P<0.001), and accessory mitral valve chordae tendineae (OR 13.1, 95%CI 4.32-39.95, P<0.001), were independently associated with LVOTO. ROC analysis showed that the area under the curve (AUC) of mitral coaptation height was higher (AUC=0.815) than the other two indicators (P<0.05).

Conclusions: Mitral coaptation height, aorto-mitral angle, and accessory mitral valve chordae tendineae, were important predictors of SAM and LVOTO in HCM independent of septal hypertrophy.

Keywords: aorto-mitral angle; echocardiography; hypertrophic cardiomyopathy; left ventricular outflow tract obstruction; mitral valve geometry.