Changes in echocardiographic parameters and strain and outcomes following mitral valve repair: insight from new mitral regurgitation classifications.

Introduction: Mitral valve repair is a cornerstone treatment for mitral regurgitation (MR), but outcomes across various etiologies remain incompletely understood. Therefore, this study aimed to comprehensively assess the outcomes of mitral valve repair across different MR etiologies, including primary MR, left ventricle functional MR (LVFMR), ischemic MR, left atrial functional MR (LAFMR), and rheumatic MR, by examining in-hospital, short-term, and medium-term outcomes, as well as the change in cardiac function through echocardiographic parameters and strain analysis. Methods: This retrospective study included 911 patients who underwent mitral valve repair at a single center from 2015 to 2021. Echocardiographic and strain analyses were performed preoperatively and at 6 months post-surgery. Mortality outcomes were assessed at in-hospital and at 6, 12, and 51 months postoperatively. Results: There were significant differences in outcomes across MR etiologies. The primary and rheumatic groups demonstrated the lowest mortality rates, whereas the LVFMR, LAFMR, and ischemic groups exhibited markedly higher mortality, both in the early postoperative period and during long-term follow-up. Echocardiographic analysis showed improvements in cardiac dimensions and volumes, but concurrent declines in myocardial function, particularly in ejection fraction, global longitudinal strain, and left atrial reservoir strain. Discussion: This study highlights the importance of etiology-specific risk stratification. While mitral valve repair effectively reduces MR, myocardial recovery may be delayed or insufficient in certain subgroups, especially those with pre-existing myocardial dysfunction. Tailored therapeutic strategies that address the multifactorial nature of functional and ischemic MR are warranted to improve long-term outcomes.