Reverse cardiac remodeling after transcatheter edge-to-edge repair for primary mitral regurgitation: a cardiac magnetic resonance study

Background Transcatheter edge-to-edge repair (TEER) effectively reduces mitral regurgitation (MR) and improves symptoms in patients at high surgical risk. However, the determinants of left ventricular reverse remodeling (LVRR) after TEER and the role of cardiac magnetic resonance (CMR) remain incompletely defined. Purpose identifying predictors of LVVR after mitral TEER1,2. Methods In this single-centre prospective study, 65 patients with degenerative MR who underwent TEER were evaluated with echocardiography and CMR before and six months after the procedure. LVRR was defined as a >10% reduction in LV end-diastolic volume (LVEDV) on follow-up CMR. Changes in MR severity and LV volumes were quantified, and predictors of LVRR were identified through linear and logistic regression analyses. Results TEER induced a significant reduction in MR severity, with concordant decrease in regurgitant volume, regurgitant fraction, and LV volumes on both echocardiography and CMR. CMR LVEDV decreased by an average of 26 ± 39 mL, and 56.9% of patients exhibited significant LVRR. CMR-derived regurgitant volume and fraction correlated strongly with the magnitude of LVEDV reduction (r = 0.59 and r = 0.57, respectively; both p < 0.001). In multivariable analysis, baseline MR regurgitant fraction (OR = 1.22, 95% CI 1.03–1.46, p = 0.003) and the reduction in MR regurgitant volume (OR = 1.31, 95% CI 1.05–1.63, p = 0.002) were independent predictors of LVRR. In figure 1 the scatter plot shows the relationship between LVRR (ΔLV EDV) assessed by CMR and MR RV assessed by CMR (on left panel) and Echo (middle panel). Both modalities demonstrate a positive association between MR severity and the degree of LV volume reduction, with stronger correlation observed for CMR-derived measurements. The shaded area represents the 95% CI of the regression line. The right panel illustrates a Bland–Altman plot comparing MR regurgitant volume derived from CMR and echocardiography. The mean bias was −20.25 mL, indicating that CMR tended to show lower MR volumes than echocardiography, with limits of agreement (LoA) from −61.66 to 21.16 mL. Conclusions Quantitative CMR assessment of MR provides robust markers of LVRR after TEER in degenerative MR. Both baseline MR severity and its reduction post-procedure showed independent association with structural recovery, emphasizing the role of CMR as a reference tool for procedural evaluation and patient selection.Figure 1.Scatter plot and Bland Altman.