5.2 TMVR: Programmatic Challenges and Technology Needed to Match Surgical Outcomes

These proceedings summarize the educational activity of the 16th Biennial Meeting of the International Andreas Gruentzig Society held January 31-February 3, 2022 in Punta Cana, Dominican Republic

Faculty Disclosures     Vendor Acknowledgments

2022 IAGS Summary Document

Statement of the problem or issue

Early intervention improves survival with surgical mitral valve replacement (SMVR) for primary degenerative mitral regurgitation (MR). Survival benefit with surgery for secondary MR is less clear. Higher recurrences of MR after repair compared to lower recurrences after replacement has caused a shift to more surgical replacements (Figure 1).^1,2

Gaps in knowledge

Issues with TMVR can be divided into 2 types: (1) programmatic; and (2) technical.

Programmatic issues

The Edwards Sapien 3 valve is the only valve available for TMVR (Figure 2).

A major issue in clinical testing of the TMVR procedure is low volume per center, especially when compared with transcatheter edge-to-edge repair (TEER).³ All other transcatheter heart valves (THVs) for TMVR are investigational. Furthermore, there are few investigational centers for the new valves, and there is very slow enrollment at investigating sites.

Technical issues

The technical challenges with TMVR are: (1) valve alignment; and (2) left ventricular outflow tract (LVOT) obstruction. First, valve alignment can be difficult due to the transseptal approach. Poor alignment leads to paravalvular leak (Figure 3).

Another technical challenge is LVOT obstruction. The reported incidence is approximately 2%. There are both fixed and dynamic causes of obstruction. Prevention is the only treatment at present.

Possible solutions and future directions

For valve alignment, possible solutions include alternative approaches, possibly even transapical. Other maneuvers include “push-pull” traction on the wire and catheter, and posterior guide deflection. The valve skirt size could be increased. Wire exteriorization via the aorta or para-apical routes may be possible. For LVOT obstruction, methods that may help are: (1) techniques to “re-orient” the transcatheter valve; (2) methods to remove the anterior leaflet via transatrial resection, LAMPOON, or BATMAN; and (3) methods to increase LVOT diameter.^4-11

The final and ultimate questions are these: Do we need:

• “More data?”

• Real-world registries or prospective trials?

• Better tools?

• To understand which patients are likely to benefit—ie, better and more focused patient selection?

References

1. Suri RM, Vanoverschelde JL, Grigioni F, et al. Association between early surgical intervention vs watchful waiting and outcomes for mitral regurgitation due to flail mitral valve leaflets. JAMA. 2013;310(6):609-616. doi:10.1001/jama.2013.8643

2. Acker MA, Parides MK, Perrault LP, et al. Mitral-valve repair versus replacement for severe ischemic mitral regurgitation. N Engl J Med. 2014;370(1):23-32. Epub 2013 Nov 18. doi:10.1056/NEJMoa1312808

3. Mack M, Carroll JD, Thourani V, et al. Transcatheter mitral valve therapy in the United States: a report from the STS-ACC TVT Registry. J Am Coll Cardiol. 2021;78(23):2326-2353. Epub 2021 Oct 25. doi:10.1016/j.jacc.2021.07.058

4. Babaliaros V, Greenbaum AB, Kamioka N, et al. Bedside modification of delivery system for transcatheter transseptal mitral replacement with POULEZ system and SAPIEN-3 valve. JACC Cardiovasc Interv. 2018;11(12):1207-1209. doi:10.1016/j.jcin.2018.03.015

5. Rahhab Z, Ren B, de Jaegere PPT, Van Mieghem NMDA. Kissing balloon technique to secure the neo-left ventricular outflow tract in transcatheter mitral valve implantation. Eur Heart J. 2018;39(23):2220. doi:10.1093/eurheartj/ehy11

6. Greenbaum AB, Lisko JC, Gleason PT, et al. Annular-to-apical “emory angle” to ensure coaxial mitral implantation of the SAPIEN 3 valve. JACC Cardiovasc Interv. 2020;13(20):2447-2450. doi:10.1016/j.jcin.2020.07.024

7. Babaliaros VC, Greenbaum AB, Khan JM, et al. Intentional percutaneous laceration of the anterior mitral leaflet to prevent outflow obstruction during transcatheter mitral valve replacement: first-in-human experience. JACC Cardiovasc Interv. 2017;10(8):798-809. doi:10.1016/j.jcin.2017.01.035

8. Case BC, Khan JM, Satler LF, et al. Tip-to-base LAMPOON to prevent left ventricular outflow tract obstruction in valve-in-valve transcatheter mitral valve replacement. JACC Cardiovasc Interv. 2020;13(9):1126-1128. Epub 2020 Apr 15. doi:10.1016/j.jcin.2020.01.235

9. Helmy T, Hui DS, Smart S, Lim MJ, Lee R. Balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction (BATMAN): a novel technique for patients undergoing transcatheter mitral valve replacement. Catheter Cardiovasc Interv. 2020;95(4):840-848. Epub 2019 Sep 13. doi:10.1002/ccd.28496

10. Wang DD, Guerrero M, Eng MH, et al. Alcohol septal ablation to prevent left ventricular outflow tract obstruction during transcatheter mitral valve replacement: first-in-man study. JACC Cardiovasc Interv. 2019;12(13):1268-1279. doi:10.1016/j.jcin.2019.02.034

11. Khan JM, Bruce CG, Greenbaum AB, et al. Transcatheter myotomy to relieve left ventricular outflow tract obstruction: the septal scoring along the midline endocardium procedure in animals. Circ Cardiovasc Interv. 2022;15(6):e011686. Epub 2022 Apr 5. doi:10.1161/CIRCINTERVENTIONS.121.011686