Anatomical Changes after Transcatheter Edge-to-Edge Repair in Functional MR According to MitraClip Generation

BACKGROUND

The use of mitral transcatheter edge-to-edge repair (TEER) is rapidly increasing. Anatomical changes have been described after TEER with the MitraClip system in patients with functional mitral regurgitation (MR), although no study has yet evaluated such anatomical impacts in patients treated with the G4 MitraClip generation.

METHODS

This research constituted a prospective, single-center, observational study including consecutive patients with functional MR. Mitral three-dimensional images were obtained transesophageally with echocardiography before and immediately after TEER. Patients receiving the late-generation (G4) system were compared to those receiving early-generation systems.

RESULTS

A total of 116 functional MR patients were evaluated, and 40 (34.5%) and 76 (65.5%) received a late-generation (G4) or early-generation device system, respectively. The baseline clinical and echocardiographic features were well-balanced between the groups. Overall, there was a significant reduction in mitral annular size after the intervention, and greater reductions in the anteroposterior diameter (4 mm vs. 3.54 mm, p = 0.03), annular perimeter (11.07 mm vs. 5.29 mm for 3D-perimeter, p = 0.001), and annular area (1.29 cm² vs. 1.03 cm², p = 0.002) were found for patients receiving the late G4 device generation compared to the early-generation systems.

CONCLUSIONS

In patients with functional MR, we observed significant changes in mitral valve anatomy with a reduction in anteroposterior diameter, valve perimeter, and area. In our cohort, the extent of those changes was greater with the use of the new-generation G4 MitraClip system compared to prior device generations.

Society of thoracic surgeons risk score and left atrial pressure for predicting clinical outcomes among transcatheter mitral edge-to-edge repair patients

BACKGROUND

Limited data exist regarding the performance of the Society of Thoracic Surgeons (STS) risk score among transcatheter mitral edge-to-edge repair (TEER) patients.

OBJECTIVE

Evaluate STS score accuracy, and the incremental value of post-procedural left atrial pressure (LAP).

METHODS

A retrospective analysis of TEER patients between 2013 and 2020. Patients were allocated into 3 groups: high (≥8% [n = 298, 31%]), intermediate (4%-8% [n = 318, 33%]), and low (<4% [n = 344, 36%]). Primary outcomes included 1-year mortality or cardiovascular hospitalizations. Cox proportional hazards regression modeling was used to determine the hazard ratio of the primary outcome, and STS score accuracy was assessed by receiver operating characteristic. A spline curve was used to display the relationship between LAP and the primary endpoint. Continuous net reclassification improvement (NRI) was used to determine the incremental value of LAP.

RESULTS

We included 960 patients, primarily elderly (79 [70-85]), with a median STS risk of 5.6 (3-9). High-risk patients were older (83 [75-89], 81 [74-87], 72 [64-79], p < 0.001), and had more comorbidities compared to intermediate and low-risk groups. Upon Cox regression, STS score (high vs. low: HR 2.5 [1.7-3.8]; Intermediate vs. low: HR 1.8 [1.2-2.7] and LAP HR 1.03 [1.01-1.06], p = 0.007) were associated with the outcome. C statistics analysis revealed low accuracy of the STS score (AUC-0.61 [0.58-0.65, p < 0.001]). Continuous NRI analysis indicated an improvement in risk prediction of 17% (6.9-26.2), p < 0.001.

CONCLUSION

STS risk score has low accuracy in predicting clinical outcomes after TEER. Adding LAP measurements can improve reclassification and identify those prone to adverse outcomes.