目的 探讨二尖瓣反流（MR）患者术前左心室收缩末内径（LVESD）所表征的左心室重构程度对术后左心室射血分数（LVEF）恢复轨迹及预后的影响。 方法 选取2020年1月至2024年12月接受二尖瓣手术的157例MR患者。按术前LVESD四分位数分为Q1—Q4组。主要结局为术后出院前、3个月、6个月的LVEF恢复轨迹，采用线性混合效应模型分析；次要结局为心力衰竭再住院或全因死亡组成的复合终点，采用Cox比例风险模型分析。 结果 与Q1组相比，Q4组患者术前LVEF更低，NT-proBNP水平更高。术后LVEF随时间显著改善（时间主效应P 0.001），但Q4组在所有时间点的LVEF均显著低于Q1组（分层主效应P 0.001），且两组间差值随时间略有缩小（交互效应P 0.01）。校正混杂因素后，Q4组LVEF在出院前、术后3、6个月仍较Q1组分别低13.10%、12.28%、12.03%（均P 0.001）。Q4组复合终点累积发生率（30.00%）显著高于Q1组（5.13%，P = 0.016）。Q4组发生复合终点的风险是Q1组的2.388倍（HR = 2.388，95%CI：1.112 ~ 5.127，P = 0.026），且风险随LVESD增大呈升高趋势（趋势P = 0.018）。敏感性分析显示，以LVESD ≥ 40 mm分层或作为连续变量分析，结论一致。 结论 术前LVESD所反映的左心室重构程度与MR患者术后早中期LVEF恢复轨迹及随访不良结局相关。LVESD较高患者术后LVEF虽可随时间改善，但整体恢复水平较低，心力衰竭再住院或全因死亡风险较高。

Objective To investigate whether the extent of preoperative left ventricular （LV） remodeling， indexed by LV end-systolic dimension （LVESD）， influences the recovery trajectory of LV ejection fraction （LVEF） and long-term prognosis following mitral valve surgery in patients with moderate-to-severe mitral regurgitation （MR）. Methods A total of 157 patients undergoing mitral valve surgery for moderate-to-severe MR between January 2020 and December 2024 were prospectively enrolled. Participants were stratified into quartiles （Q1 - Q4） based on preoperative LVESD. The primary outcome was the longitudinal trajectory of LVEF assessed at pre-discharge， 3 months， and 6 months postoperatively， analyzed using linear mixed-effects models. The secondary outcome was a composite endpoint of heart failure rehospitalization or all-cause mortality， evaluated by Cox proportional hazards regression. Results CCompared with the Q1 group， patients in the Q4 group exhibited significantly lower preoperative LVEF and higher NT-proBNP levels （P 0.05）. LVEF improved significantly over time across the cohort （time effect， P 0.001）； however， the Q4 group demonstrated consistently lower LVEF than Q1 at all postoperative timepoints （group effect， P 0.001）， with a modest attenuation of between-group differences over time （time × group interaction， P = 0.008）. After multivariable adjustment， LVEF in the Q4 group remained 13.10， 12.28， and 12.03 percentage points lower than in Q1 at pre-discharge， 3 months， and 6 months， respectively （all P 0.001）. The cumulative incidence of the composite endpoint was significantly higher in Q4 （30.0%） versus Q1 （5.1%， log-rank P = 0.016）. Multivariable Cox analysis identified Q4 membership as an independent predictor of adverse outcomes （adjusted HR = 2.39， 95% CI： 1.11 ? 5.13， P = 0.026）， with a significant dose?response relationship across LVESD quartiles （P for trend = 0.018）. Sensitivity analyses using LVESD ≥ 40 mm as a binary cutoff or modeling LVESD as a continuous variable yielded consistent results. Conclusions Preoperative LVESD， as a marker of LV remodeling severity， independently predicts both the trajectory of early- to mid-term LVEF recovery and adverse clinical outcomes after mitral valve surgery for MR. Although patients with advanced remodeling （higher LVESD） exhibit postoperative LVEF improvement， their absolute recovery remains suboptimal， and they face substantially elevated risks of heart failure rehospitalization or mortality. These findings support earlier surgical intervention before irreversible LV dilation occurs.