Clinical Investigations
Echocardiography and Transcatheter Edge-to-Edge Repair
Anatomical and Technical Predictors of Three-Dimensional Mitral Valve Area Reduction After Transcatheter Edge-To-Edge Repair

https://doi.org/10.1016/j.echo.2021.08.021Get rights and content

Highlights

  • The final 3D MVA after TEER depends on the type and position of the implanted device.

  • Maximal MVA reduction does not occur with TEER device in the middle of MV.

  • MVA is reduced less if a second clip creates a double rather than triple orifice (25% vs 34%).

  • The minimal MVA needed for TEER ranges from 3.5 to 6.3 cm2.

Background

Among current transcatheter therapies for the treatment of mitral regurgitation, the MitraClip (MC; Abbott Vascular, Abbott Park, IL) system is the most commonly used. MitraClip implantation is usually contraindicated in patients with a mitral valve area (MVA) < 4.0 cm2. However, little is known about the real impact of MC implantation on MVA. Our goal was to investigate the factors influencing MVA reduction and derive the minimal MVA required to prevent the development of a clinically significant mitral stenosis (MVA < 1.5 cm2) in different clinical scenarios.

Methods

Using three-dimensional data sets, the annulus and leaflet anatomy and MVA before clip implantation (MVABC) were assessed. After each MC implant (NTR or XTR), the relative MVA reduction and the absolute residual MVA were measured and their predictors evaluated.

Results

The present analysis included 116 patients. An MC XTR was the first device implanted in 50% of the subjects, and 53% were treated with a single implant. The MVA reduction following one XTR was 57% ± 7% versus 52% ± 8% after one NTR (P = .001). A lower MVA reduction was observed when the MC was placed commissural/central versus paracentral (50% ± 8% vs 57% ± 7%, P < .0001). After a second device, the additional MVA reduction was higher when creating a triple-compared with a double-orifice morphology (34% ± 11% vs 25% ± 9%, P = .001). The MVA after one MC correlated with MVABC as well as with the clip type and position (r = 0.91, P < .0001). The MVABC, orifice morphology, and first device position predicted MVA after two implants (r = 0.82, P < .0001). Based on the mathematical relationship between these parameters, the minimal MVABC needed in eight different clinical scenarios was summarized in a decision algorithm: the values ranged from 3.5 to 4.7 cm2 for one and 4.5 to 6.3 cm2 for two MC strategies.

Conclusions

The minimal native MVA preventing clinically relevant MS after transcatheter edge-to-edge repair is predicted by the number and location of clip(s), orifice morphology, and device type. Based on these parameters, an algorithm has been derived to optimize patient selection and preprocedural planning.

Section snippets

Study Design and Patient Selection

Since 2017, peri-interventional 3D B-mode and color Doppler data acquisition of the MV has been performed by a dedicated team of interventional echocardiographers. Consecutive patients with symptomatic MR undergoing treatment by TEER with MC (Abbott Vascular, Abbott Park, IL) at a single tertiary center (Bern University Hospital) during the period 2017–19 were considered for this analysis. All patients were deemed clinically and anatomically suitable for TEER with the MC system (NTR or XTR) by

Baseline Clinical and Procedural Characteristics

Between March 2017 and December 2019, 150 patients undergoing TEER with the MC were included in an institutional registry for MV interventions. Among them, 116 patients (77%) fulfilled the inclusion criteria of the present analysis. Baseline characteristics of the study cohort are summarized in Table 1. The median age was 81 (76-85) years, 42% were female, 47% had primary MR, and 94% had moderate to severe MR (grade 3+ or 4+). An XTR clip was implanted as the first device in 50% of the

Discussion

This is the first study to systematically evaluate 3D MVA changes after each individual MC implant in a sizeable population of patients and model technical and anatomical parameters to predict the minimal MVABC needed to prevent clinically significant MS in different clinical scenarios.

The principal findings of this study can be summarized as follows:

  • 1.

    The final 3D MVA after MC implantation(s) depends not only on the size of the native valve but also on the type and position of the clip(s) used.

  • 2.

Conclusion

The minimal native baseline MVA preventing clinically relevant MS after TEER is predicted by the number and location of clip(s), orifices morphology, and device type. Based on these parameters, an algorithm has been derived to optimize patient selection and preprocedural planning. We propose a new refined method for MVA measurement accounting for the multiplanarity of the orifice of native nonstenotic MV.

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Conflicts of Interest: F.P. reports travel expenses from Abbott Vascular, Edwards Lifesciences, and Polares Medical. T.P. has received research grants to the institution from Edwards Lifesciences, Symetis/Boston Scientific, and Biotronik and speaker fees from Boston Scientific and Biotronik. S.W. reports research and educational grants to the institution from Abbott, Amgen, BMS, Bayer, Boston Scientific, Biotronik, Cardinal Health, CardioValve, CSL Behring, Daiichi Sankyo, Edwards Lifesciences, Johnson & Johnson, Medtronic, Querbet, Polares, Sanofi, Terumo, and Sinomed; serves as an unpaid advisory board member and/or unpaid member of the steering/executive group of trials funded by Abbott, Abiomed, Amgen, Astra Zeneca, BMS, Boston Scientific, Biotronik, Cardiovalve, Edwards Lifesciences, MedAlliance, Medtronic, Novartis, Polares, Sinomed, V-Wave, and Xeltis but has not received personal payments by pharmaceutical companies or device manufacturers; is a member of the steering/executive committee group of several investigated/initiated trials that receive funding by industry without impact on his personal remuneration; and is an unpaid member of the Pfizer Research Award selection committee in Switzerland. All other authors do not have relationships relevant to the contents of this paper to disclose.

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