Residual Mitral Regurgitation and Gradient Following Mitral Valve Transcatheter Edge-to-Edge Repair

Background
Residual mitral regurgitation (MR) ≥2+ and mean transmitral valve gradient (MVG) >5 mmHg have been associated with adverse outcomes following mitral valve transcatheter edge-to-edge repair (M-TEER). Recently, MR reduction to ≤1+ has been shown to be associated with clinical benefits, regardless of MVG following M-TEER with the MitraClip (Abbott Structural). We aimed to validate these findings with the PASCAL system (Edwards Lifesciences).
 
Methods
The REPAIR study (REgistry of PAscal for mItral Regurgitation) is an ongoing, investigator-initiated, retrospective, multicenter registry including all-comers treated with the PASCAL for MR across 14 centers in Germany from 02/2019 to 06/2024. Subjects were categorized into 4 groups based on MR grade and MVG at discharge: 1) MR ≤1+/MVG <5 mmHg; 2) MR ≤1+/MVG ≥5mmHg; 3) MR ≥2+/MVG <5 mmHg; and 4) MR ≥2+/MVG ≥5 mmHg.

Results
A total of 2,000 patients (age 80 [74-84], 44% female, 85% NYHA class III/IV, EuroScore II 4.9% [3.0-8.2]) with available discharge echocardiograms were included: 1,187 (59.4%) with MR ≤1+/<5 mmHg, 248 (12.4%) with MR ≤1+/MVG ≥5 mmHg, 423 (21.1%) with MR ≥2+/MVG <5 mmHg, and 142 (7.1%) with MR ≥2+/MVG ≥5 mmHg. MR etiology differed significantly across groups, with secondary MR (SMR) most prevalent in the MR ≤1+/MVG <5 mmHg group (56%) and least frequent in MR ≥2+/MVG ≥5 mmHg (39%), p<0.001 across groups. Overall, significant 1-year survival differences across these groups were observed (log-rank p=0.005) (Figure 1). These findings were confirmed for both patients with primary MR (PMR, log-rank p=0.043) and SMR (log-rank p=0.034). After Bonferroni correction, patients with MR ≤1+/MVG <5 mmHg had superior survival (91% [95% CI: 89-93]) compared to those with MR ≥2+/MVG ≥5 mmHg (79% [95% CI: 72-88], log-rank p=0.007). No significant difference was found for MVG ≥5 mmHg vs <5 mmHg (log-rank p=0.13) (Figure 2), consistent in both PMR (log-rank p=0.17) and SMR (log-rank p=0.29). In contrast, MR ≤1+ vs ≥2+ showed a significant difference (log-rank p<0.001) (Figure 3), confirmed for both PMR (log-rank p=0.014) and SMR (log-rank p<0.001).
 
Conclusions
Our analysis confirms that achieving an MR reduction to ≤1+ is associated with a survival benefit, independent of MVG. This underscores minimal residual MR as a key target in optimizing outcomes following M-TEER across different devices.

Figure 1. Kaplan-Meier survival analysis by combined residual MR grade and MVG at discharge, showing significant differences in 1-year survival across the four groups (log-rank p=0.005).

Figure 2. Kaplan-Meier survival analysis by MVG (≥5 mmHg vs. <5 mmHg) at discharge, indicating no significant difference in 1-year survival based on MVG alone (log-rank p=0.13).

Figure 3. Kaplan-Meier survival analysis by residual MR grade (≤1+ vs. ≥2+) at discharge, demonstrating significantly improved 1-year survival in patients achieving MR ≤1+ (log-rank p<0.001).