Left atrial reservoir strain by speckle-tracking echocardiography predicts prognosis in secondary mitral valve insufficiency

Background Functional mitral regurgitation (FMR) contributes significantly to morbidity and mortality and may result from left ventricular (VFMR) or atrial (AFMR) remodelling. Left atrial reservoir strain (LASR) is a sensitive marker of atrial dysfunction and may offer incremental prognostic value. This study evaluated whether LASR predicts all-cause mortality and heart failure (HF) hospitalizations in FMR, its performance in VFMR versus AFMR, and its utility over standard echocardiographic parameters. Methods We retrospectively analyzed 102 patients (mean age 68 ± 14 years, 41.2% female) with at least moderate FMR who underwent transesophageal echocardiography between 2018 and 2023. Patients were categorized into VFMR (LV dysfunction or remodelling) and AFMR (LA enlargement with preserved LV function). LASR was assessed using speckle-tracking echocardiography. Primary and secondary endpoints were all-cause mortality and HF hospitalization, respectively. Cox models evaluated associations with outcomes, including subgroup analysis by LASR quartiles and additional risk stratification combining LASR with peak tricuspid regurgitation (TR) velocity. Results LASR was independently associated with all-cause mortality in multivariate Cox regression (adjusted HR = 0.887, p = 0.039). Higher LASR quartiles were associated with improved survival ( p = 0.013). When combined with peak TR velocity in a composite risk model, patients with LASR ≤ 9.0% or TR velocity > 3.0 m/s had significantly higher risks of mortality (HR = 2.853, p = 0.012) and HF hospitalization (HR = 3.922, p = 0.029). Conclusions LASR, particularly when combined with TR velocity, provides strong prognostic value in FMR, supporting its potential role in refining risk assessment.