Ventricular FMR patients had higher MR improvement under medical therapy, with LVEDV, LVESV, and LA volume reductions independently predicting MR improvement (HRs 0.422, 0.486, 0.149).
What are the clinical and echocardiographic predictors of mitral regurgitation improvement under medical therapy across different functional mitral regurgitation phenotypes?
Ventricular-type functional mitral regurgitation is more likely to improve under medical therapy than atrial-type, with reverse remodeling of the left ventricle and atrium serving as independent predictors of improvement.
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Abstract Introduction Functional mitral regurgitation (FMR) is categorized into ventricular and atrial subtypes based on underlying mechanisms of atrial dilatation or ventricular dysfunction. Given the limited surgical evidence available, this study aimed to evaluate left atrial and ventricular remodeling and identify clinical predictors of mitral regurgitation (MR) improvement under medical therapy across different FMR phenotypes. Methods Subjects with at least moderate to severe FMR, diagnosed by transthoracic echocardiography, were included. FMR was then classified into three phenotypes: atrial FMR (aFMR), ischemic FMR (iFMR), and non-ischemic ventricular FMR (vFMR). Echocardiographic parameters were assessed at baseline and during follow-up. MR improvement was defined as a reduction to trivial or mild MR during follow-up. The study population was followed for three years. Results A total of 187 subjects (mean age: 71.3 ± 14.4 years; 60% male) were enrolled, including 70 with iFMR, 64 with non-ischemic vFMR, and 53 with aFMR. During a median follow-up of 929 days, 82 (43.9%) patients demonstrated MR improvement. Subjects with MR improvement were younger, had a lower prevalence of atrial fibrillation (AF), lower baseline left ventricular ejection fraction (LVEF), larger baseline left ventricular end-diastolic volume index (LVEDVi) and left ventricular end-systolic volume index (LVESVi), smaller baseline left atrial (LA) diameter and volume index (LAVi), a lower baseline global longitudinal strain (GLS) of the left ventricle (LV) and LA conduit strain. Additionally, patients with MR improvement exhibited greater changes in LVEF, LVEDV, LVESV, and LA volume over time. Time-to-event analysis revealed a significantly higher probability of MR improvement in the vFMR group compared to the aFMR group with a log-rank P-value of 0.031. Univariate analysis showed that vFMR phenotype, LVEF, LVEDVi, LVESVi, LVESDi, LAVi, and changes in LVEDV, LVESV, and LA volume were associated with MR improvement. After adjusting for age, sex, and estimated glomerular filtration rate (eGFR), changes in LVEDV, LVESV, and LA volume remained independent predictors of MR improvement (HR 95% CI: 0.422 0.193–0.920, 0.486 0.263–0.901, and 0.149 0.053–0.424, respectively). Conclusions Among patients with functional mitral regurgitation, those with ventricular-type FMR (vFMR) were more likely to experience MR improvement under medical therapy compared to those with atrial-type FMR (aFMR). Additionally, reductions in left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left atrial (LA) volume were independently associated with MR improvement. These findings suggest that ventricular remodeling may play a role in MR reversibility, particularly in patients with vFMR.Volumetric changes and MR improvement Predictors of MR improvement
Lu et al. (Sat,) reported a other. Ventricular FMR patients had higher MR improvement under medical therapy, with LVEDV, LVESV, and LA volume reductions independently predicting MR improvement (HRs 0.422, 0.486, 0.149).