Primary Mitral Regurgitation: Toward a Better Quantification on Left Ventricular Consequences

Background: Left ventricular end-systolic diameter (LVESD) and ejection fraction (LVEF) are the parameters to look for when discussing repair in asymptomatic patients with a primary mitral regurgitation (PMR). Loading conditions are altering LV-function quantification. LV-myocardial work (LVMW) is a method based on pressure-strain loops. Hypothesis: We sought to evaluate the additive value of the LVMW for predicting clinical events in patients with PMR. Methods: 103 patients (66% men, median age 57 years) with asymptomatic severe PMR were explored at rest and during an exercise stress echocardiography. 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 low workload. The indication for surgery was based on the heart teams' decision. The median follow-up was 670 days. Results: Clinical events occurred for 50 patients (48.5%) with a median of event-free survival distribution of 289 days. Systolic pulmonary artery pressure (sPAP) at rest was 32.61 +/- 8.56 mmHg and did not predict the risk of event like LVEF and LVESD. Changes in, GLS (hazard ratio [HR] 0.55; 95% confidence interval (Cl): 0.36-0.83; p = .005), GWI (HR 1.01; 95% Cl: 1.00-1.02; p = .002) and GCW (HR 1.85; 95% Cl: 1.28-2.68; p = .001) in addition to Left Atrial Volume Index (HR 1.73; 95% CI: 1.28 - 2.33; p < 0,001) were independent predictors of events. Conclusion: Changes in myocardial work indices related to low-dose exercise are relevant to best predict PMR patient prognosis It might help to better select patient's candidate for "early-surgery."