In primary mitral regurgitation (PMR), the indication for surgery is more and more suggested in asymptomatic patients. Diameter and ejection fraction remains the main parameters to look at despite very promising results obtained with the use of left ventricular global longitudinal strain (LV-GLS). Load remains an issue in interpreting the GLS. Left ventricular myocardial work (LVMW) is a novel method to assess left ventricular function using pressure-strain loops that takes into consideration LV afterload (Fig. 1).

This study aimed to evaluate the additive value of the LVMW for prediction of clinical events in patients with PMR.

One hundred and three patients (68% men, median age 57years) with significant PMR were retrospectively analysed from the echocardiographic databases of the hospitals of Rennes and Lille. LV-GLS, LV myocardial global work index (GWI), constructive work (GCW), wasted work (GWW) and work efficiency (GWE) were measured with speckle tracking echocardiography at rest and at low load (25W). These patients were all asymptomatic and were followed. The indication for surgery was based on the heart teams decision. The regurgitation was quantified according to EACVI recommendations. Pulmonary pressures left atrial size, rhythm, output were all considered. The median follow-up was 670days.

Clinical events occurred for 50 patients (48.5%) with a median of event-free survival distribution of 289days. It was an indication for surgery for 72 patients (69,9%). sPAP at rest was 32.61±8.56 and did not predict the risk of event as well as LVEF, LVESD when compared to GLS (−2.177±1.180), GWI (0.045±0.015), GCW (0.908±0.496), GWW (−0.088±0.109) or GWE (2.179±3.266). On multivariate Cox models, only GLS [HR: 0.55; 95% confidence interval (CI): 0.36–0.83; P=0.005], GWI (HR: 1.01; 95% CI: 1.00–1.02; P=0.002) and GCW (HR: 1.85; 95% CI: 1.28–2.68; P=0.001) were independent predictors of clinical events. GLS is correlated with myocardial work indices who are shown to improve the capability to link echo-findings to the risk of event at about one year follow-up.

Myocardial work indices at rest seem relevant to best predict the risk of event and then, instead of stressing all the patient, a careful consideration of MW in addition to the recommend parameters advised by guidelines could help to select the patients who should be considered for an earlier highly likely mitral valve repair.