[Clinical and echocardiographic parameters associated with the alteration of global longitudinal strain in secondary mitral regurgitation]

Abstract

Introduction: Left ventricular systolic function may be overestimated in patients with secondary mitral regurgitation when using left ventricle ejection fraction. The Global longitudinal strain is a measure less dependent on left ventricle load. However, the clinical and echocardiographic parameters associated with the alteration of Global longitudinal strain in secondary mitral regurgitation have not been evaluated.

Material and methods: A total of 96 patients (mean age 62.3 ± 12.1 years, 59.3% male) with secondary mitral regurgitation and low left ventricle ejection fraction < 50% were included. The study population was subdivided according to the Global longitudinal strain value with which an increased risk of all-cause mortality was associated (Global longitudinal strain < 7.0%, left ventricle systolic function impaired compared to Global longitudinal strain ≥ 7.0%, in absolute value). The clinical and echocardiographic endpoints are analysed in both groups of patients.

Results: The strong and clear correlation between Global longitudinal strain (mean ± standard deviation: 7,2 ± 2,7) and parameters of systolic function (left ventricle ejection fraction mean ± standard deviation: 32,4 ± 8,0%) and contractility (dp/dt mean ± standard deviation: 682,5 ± 204,7 mmHg/s). the mean of left ventricle ejection fraction = 26.4 ± 5.3% in the Global longitudinal strain < 7 group, and the bivariate study using the 30% threshold shows that the Global longitudinal strain < 7 group presents a more altered left ventricle ejection fraction with odds ratio = 12, 5 (CI: 4.7-33.0) p < 0.001. In multivariate analysis of ultrasound parameters and linear regression shows a significant correlation between Global longitudinal strain and left ventricle ejection fraction (p < 0.001). The dp/dt analysis found a mean of 509.3 ± 99.1 mmHg/s in the Global longitudinal strain < 7 group and of 822.9 ± 154.1 in the Global longitudinal strain ≥ 7 group with significant difference (p < 0.001). In bivariate and multivariate analysis, the alteration of Global longitudinal strain is associated with a significantly lower dp / dt p < 0.001.

Conclusion: A Global longitudinal strain < 7 (in absolute value) reflects a severe impairment of left ventricle function. In addition, several parameters were associated with this severe alteration of the Global longitudinal strain, namely a lower left ventricle ejection fraction, a lower dp/dt and more severe symptoms permitting to characterized this group of patients in addition to an integration in a multiparametric evaluation of the secondary mitral regurgitation.

Keywords: Echocardiography; Global longitudinal strain; Insuffisance mitrale secondaire; Left ventricular dysfunction; Morbidity and mortality; Secondary mitral regurgitation; dysfonction Ventricule gauche; morbimortalité; strain longitudinal global; échocardiographie.