Feasibility of Coronary Access Following Redo-TAVR for Evolut Failure: A Computed Tomography Simulation Study

Management of difficult coronary anatomy during transcatheter aortic valve implantation: what are the key issues?

PURPOSE OF REVIEW

Predicting and preventing coronary obstruction in transcatheter aortic valve replacement (TAVR) is crucial due to its high mortality risk.

RECENT FINDINGS

In native TAVR, predicting coronary obstruction requires assessing aortic cusp height, coronary artery height, valve-to-coronary distance, and leaflet calcium volume. The VIVID classification has been proposed for evaluating the risk of coronary obstruction in TAVR for failed bioprosthetic surgical valves. After TAVR with the Sapien 3 valve, the feasibility of redo TAVR and coronary access decreases with a shallower implantation of the initial Sapien 3. In redo TAVR of Sapien 3 within an Evolut valve, positioning the Sapien 3 outflow at node 4 improves redo TAVR feasibility and coronary accessibility compared to positioning at nodes 5 or 6. For valve sizing in redo TAVR with Sapien 3, in-vivo CT sizing results in smaller valve sizes than bench sizing, reducing coronary risk and improving redo TAVR feasibility. Leaflet modification and coronary stenting techniques and a dedicated leaflet-splitting device have been proposed to maintain coronary perfusion in high-risk cases.

SUMMARY

Coronary preservation in high-risk TAVR remains a significant challenge, requiring further research into preprocedural planning and leaflet modification strategies.

Redo-Transcatheter Aortic Valve Replacement Procedural Optimization and Patient Selection: From Bench to Clinical Practice

With recent guidelines expanding transcatheter aortic valve replacement (TAVR) to younger patients, indications for redo-TAVR will also likely increase. When compared with TAVR, redo-TAVR is a rare and novel procedure. Current clinical data derived from registries suggest excellent safety, with low rates of 30-day and 1-year mortality following redo-TAVR. Proper understanding of data from bench studies regarding optimal valve configurations, of patient anatomy and of the technical properties of transcatheter heart valves (THV) is essential for patient selection and procedural success. Lifetime management of redo-TAVR should start before the index procedure, as the choice of the index THV has a major impact on the feasibility of redo-TAVR. Procedural optimization by adequate valve sizing, commissural alignment and adequate implant depth of both index and redo-THV are critical determinants of optimal hemodynamics for maximized valve longevity, as well as lifelong coronary access.

Current hotspot and study trend of transcatheter aortic valve replacement, a bibliometric analysis from 2009 to 2023

Introduction

Transcatheter aortic valve replacement (TAVR), alternatively termed transcatheter aortic valve implantation (TAVI), represents a seminal advancement in cardiovascular interventions by obviating the necessity for open-heart surgery traditionally associated with surgical aortic valve replacement (SAVR). This technique entails percutaneous delivery of a bioprosthetic valve. Despite the surfeit of literature on TAVR over the past fifteen years, a bibliometric analysis is conspicuously absent.

Method

A query executed on the Web of Science Core Collection (WoSCC) on September 1, 2022, returned 8,359 articles and reviews pertinent to TAVR. Data interpretation leveraged Microsoft Excel, CiteSpace, and VOSviewer to illustrate trends and delineate focal points within the corpus of TAVR research.

Result

The analysis incorporated 8,359 articles and reviews on TAVR from January 1, 2009, to August 1, 2023. Publication volume expanded from 35 in 2009 to a pinnacle in 2020, reflecting a near thirty folds increase, with citations escalating from 56 in 2009 to 27,354 in 2021. The United States prevailed in scholarly output (Np = 3,015), citation frequency (Nc = 70,991, excluding self-citations), and academic impact (H-index = 120). Columbia University was distinguished by the highest number of publications (Np = 380), citations (Nc = 41,051), and H-index (84). Within the author community, Rodes-Cabau J was preeminent, with 260 publications and an equivalent citation index and H-index. Keywords such as "balloon-expandable valve," "coronary access," "next-day discharge," "conducti on disturbances," and "coronary obstruction" have surfaced as the lexicon of burgeoning research themes.

Conclusion

Investigation into TAVR has emerged as a major area of scholarly focus. The United States stands at the forefront of this research. Columbia University ranks as the preeminent institution in terms of publication output. Key research themes such as "balloon-expandable valve," "coronary access," and "coronary obstruction" are shaping up as current and prospective research hotspots, signaling potential areas for future study and innovation.

Feasibility of redo-TAVI in the self-expanding ACURATE neo2 valve: a computed tomography study

BACKGROUND

Redo-transcatheter aortic valve implantation (TAVI) may be unfeasible because of the risk of compromising coronary flow or coronary access by the pinned back leaflets of the index transcatheter aortic valve.

AIMS

We aimed to evaluate the feasibility of redo-TAVI using the balloon-expandable SAPIEN 3 (S3) implanted within the self-expanding ACURATE neo2 (ACn2) valve and to identify predictors associated with a high risk of compromising coronary flow.

METHODS

A total of 153 post-ACn2 TAVI cardiac computed tomography scans were analysed. Redo-TAVI using an S3 was simulated in two positions: S3 outflow to the ACn2 upper crown (low implant) and S3 outflow to the base of the ACn2 commissural posts (high implant). The risk for coronary flow compromise and inaccessibility was determined by the height of the neoskirt created by the pinned back leaflets and the valve-to-aorta distances.

RESULTS

At a low S3 implant position, risk of coronary flow compromise was predicted in only 8% of patients and this increased to 60% with a high S3 position. In accordance, coronary access was predicted to be unrestricted in 52% versus 13% of patients with a low versus high S3 implantation. Female sex, a small aortic annular dimension and a sinotubular junction-to-aortic annulus mean diameter ratio <1.15 were independent predictors associated with a high risk for coronary flow compromise.

CONCLUSIONS

The feasibility of redo-TAVI with an S3 in an ACn2 depends on the implant depth of the S3 and the geometry of the surrounding aorta. A low S3 implant may reduce the risk of coronary flow compromise and inaccessibility.

Navitor™ in Evolut™: a case report illustrating a novel approach to redo-transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) is expanding to younger patients, and the management of valve failure is a growing clinical problem. The transcatheter heart valve (THV) of choice for redo-TAVI is a complex decision, and first reports have examined the use of the Sapien 3™ THV (Edwards Lifesciences; Irvine, CA, USA) in failed Evolut™ (Medtronic, Minneapolis, MN, USA) THV. However, several different technical approaches may be worth consideration, and the subject remains a matter of debate.

Case summary

A 73-year-old female with previous coronary artery bypass grafting, percutaneous coronary intervention (PCI), and TAVI with a 26 mm Evolut™ R THV presented with signs of heart failure. The clinical investigation revealed a severe restenosis of the THV valve and a stenosis of the left coronary main stem. The patient was successfully treated with PCI of the left main and, during the same procedure, underwent implantation of a 25 mm Navitor™ THV (Abbott; Chicago, IL, USA).

Discussion

This case presentation aims to illustrate the rationale of and necessary conditions for performing a TAVI-in-TAVI procedure with Navitor™ THV in a failed Evolut™ THV which, to our best knowledge, constitutes a novel approach to redo-TAVI.

Management of bicuspid aortic valve disease in the transcatheter aortic valve implantation era

In an era of rapidly expanding use of transcatheter aortic valve implantation (TAVI), the management of patients with bicuspid aortic valve (BAV) disease is far less well established than in those with trileaflet anatomy. Results of isolated surgical aortic valve replacement are excellent in suitable patients, and surgery also allows treatment of concomitant pathology of the aortic root and ascending aorta that is frequently encountered in this cohort. Conversely, TAVI provides an excellent alternative in older patients who may be unsuitable for surgery, although outcomes in BAV disease have only been reported in relatively small non-randomised series. Here, we discuss the pertinent literature on this topic and outline contemporary interventional treatment options in this challenging setting.

Impact of leaflet splitting on coronary access after redo-TAVI for degenerated supra-annular self-expanding platforms

BACKGROUND

Coronary access (CA) is a major concern in redo-transcatheter aortic valve implantation (TAVI) for failing supra-annular self-expanding transcatheter aortic valves (TAVs).

AIMS

This ex vivo study evaluated the benefit of leaflet splitting (LS) on subsequent CA after redo-TAVI in anatomies deemed at high risk of unfeasible CA.

METHODS

Ex vivo, patient-specific models were printed three-dimensionally. Index TAVI was performed using ACURATE neo2 or Evolut PRO (TAV-1) at the standard implant depth and with different degrees of commissural misalignment (CMA). Redo-TAVI was performed using the balloon-expandable SAPIEN 3 Ultra (TAV-2) at different implant depths with commissural alignment. Selective CA was attempted for each configuration before and after LS in a pulsatile flow simulator. The leaflet splay area was assessed on the bench.

RESULTS

In matched comparisons of 128 coronary cannulations across 64 redo-TAVI configurations, the overall feasibility of CA significantly increased after LS (60.9% vs 18.7%; p<0.001). The effect of LS varied according to the sinotubular junction height, TAV-1 design, TAV-1 CMA, and TAV-2 implant depth, given TAV-2 alignment. LS enabled CA for up to CMA 45° with the ACURATE neo2 TAV-1 and up to CMA 30° with the Evolut PRO TAV-1. The combination of LS and a low TAV-2 implant provided the highest feasibility of CA after redo-TAVI. The leaflet splay area ranged from 25.60 mm2 to 37.86 mm2 depending on the TAV-1 platform and TAV-2 implant depth.

CONCLUSIONS

In high-risk anatomies, LS significantly improves CA feasibility after redo-TAVI for degenerated supra-annular self-expanding platforms. Decisions on redo-TAVI feasibility should be carefully individualised, taking into account the expected benefit of LS on CA for each scenario.

Transcatheter Aortic Valve Implantation to Treat Degenerated Aortic, Mitral and Tricuspid Bioprosthesis

Transcatheter aortic valve implantation (TAVI) is now well established as the treatment of choice for patients with native aortic valve stenosis who are high or intermediate risk for surgical aortic valve replacement. Recent data has also supported the use of TAVI in patients at low surgical risk and also in anatomical subsets that were previously felt to be contra-indicated including bicuspid aortic valves and aortic regurgitation. With advancements and refinements in procedural techniques, the application of this technology has now been further expanded to include the management of degenerated bioprosthesis. After the demonstration of feasibility and safety in the management of degenerated aortic bioprosthetic valves, mitral and tricuspid bioprosthetic valve treatment is now also well-established and provides an attractive alternative to performing redo surgery. In this review, we appraise the latest clinical evidence and highlight procedural considerations when utilising TAVI technology in the management of degenerated aortic, mitral or tricuspid prosthesis.