Assessment of novel echocardiographic indices of myocardial function in patients with significant primary mitral regurgitation

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. INTRODUCTION Assessment of left ventricular (LV) function in primary mitral regurgitation remains challenging due to ejection fraction preservation, even in late stages of the disease. Global longitudinal strain (GLS) remains a valuable tool for the assessment of systolic function which is affected, like ejection fraction, by loading conditions. Lately, novel methods, such as myocardial work estimated by echocardiography, have been developed in assessment of LV systolic function, along with left atrial strain in assessment of diastolic function. Early identification of systolic or diastolic dysfunction in primary mitral regurgitation is crucial for further management of these patients. PURPOSE In this study we assessed several indices of LV systolic and diastolic function, such as myocardial work, global longitudinal strain and left atrial strain, in patients with significant primary mitral regurgitation, in order to evaluate early myocardial dysfunction. METHODS We retrospectively assessed echocardiograms of 64 patients, referred to an echocardiography laboratory of a tertiary hospital between 2019 and 2021 with the diagnosis of significant primary MR. Measurements included several echocardiographic indices of LV anatomy and function, such as left atrial volume indexed (LAVi), left atrial strain, global longitudinal strain (GLS), pulmonary hypertension and global myocardial work. Finally we correlated various indices of systolic and diastolic function with severity of mitral regurgitation. RESULTS We analyzed echocardiograms of 64 patients (50 men, mean age 60 ± 13,8) with at least moderate organic MR, 75,8% of which had severe MR, and normal ejection fraction (mean EF 63%±4,9). We identified negative correlation between left atrial strain (reservoir) and pulmonary hypertension measurements (correlation coefficient -358, p < 0,05) in patients with at least moderate MR. However, we were not able to find any statistically significant differences in GLS (21,98 vs 22,26) or myocardial work, even though we noticed a difference in myocardial work between patients with moderate and severe MR (Global Work Index 2302mmHg% vs 2262mmHg% with normal values 2209 ± 307mmHg% in STAAB cohort, Global Constructed Work 2540mmHg% vs 2327mmHg%, Global Waste Work 136,89mmHg% vs 136,43mmHg%, Global Work Efficiency 94,22% vs 93,76%). CONCLUSIONS These data suggest that an early assessment of indices of diastolic function, such as left atrial strain linked to pulmonary hypertension, can guide to a more effective evaluation of patients with severe MR and normal systolic function. Additionally, novel indices of LV function less load-dependent, such as myocardial work, are promising tools in the assessment of left ventricle and early recognition of myocardial dysfunction in patients with severe organic MR, but more prospective studies are needed. Abstract Figure. Abstract Figure.