Prognostic value of myocardial work and global longitudinal strain in patients with heart failure and functional mitral regurgitation.

In patients with heart failure and functional mitral regurgitation (FMR), the assessment of left ventricular (LV) function is important for risk stratification and decision making. As LV ejection fraction (LVEF) might not be an optimal metric for LV systolic performance in this population, alternatives such as global longitudinal strain (GLS) and global myocardial work index (GWI) have been proposed. In the present study, we investigated the prognostic value of GLS and GWI and compared these measures to other LV systolic performance parameters. A prospective and consecutive cohort of 181 patients (median age 72 years, 76% male) with LVEF < 50% and FMR underwent comprehensive echocardiographic examination including speckle tracking echocardiography and grading of FMR severity. During a median follow-up of 42 months, 72 cardiovascular (CV) events occurred. In univariate analysis, LVEF, GLS, GWI, mitral S', LV outflow tract time velocity integral, forward LVEF and LV ejection time were associated with CV events. After multivariate adjustment only GLS (hazard ratio (HR) = 0.884, p = 0.015) and GWI (HR = 0.927, p = 0.034) remained independently associated with CV events. There was no difference in the incremental prognostic value of GWI compared to GLS (delta -2 log likelihood = 0.8; p = 0.37). In this cohort of heart failure patients with FMR, GLS and GWI were independently associated with cardiovascular events, whereas other systolic performance parameters were not. However, GWI did not outperform GLS, and further research is required to determine the value of these strain-based measures in clinical practice.