Coronary re-access after redo TAVI: a proposed classification to simplify evaluation

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.

Coronary access following ACURATE neo implantation for transcatheter aortic valve-in-valve implantation: Ex vivo analysis in patient-specific anatomies

Background

Coronary access after transcatheter aortic valve implantation (TAVI) with supra-annular self-expandable valves may be challenging or un-feasible. There is little data concerning coronary access following transcatheter aortic valve-in-valve implantation (ViV-TAVI) for degenerated surgical bioprosthesis.

Aims

To evaluate the feasibility and challenge of coronary access after ViV-TAVI with the supra-annular self-expandable ACURATE neo valve.

Materials and methods

Sixteen patients underwent ViV-TAVI with the ACURATE neo valve. Post-procedural computed tomography (CT) was used to create 3D-printed life-sized patient-specific models for bench-testing of coronary cannulation. Primary endpoint was feasibility of diagnostic angiography and PCI. Secondary endpoints included incidence of challenging cannulation for both diagnostic catheters (DC) and guiding catheters (GC). The association between challenging cannulations with aortic and transcatheter/surgical valve geometry was evaluated using pre and post-procedural CT scans.

Results

Diagnostic angiography and PCI were feasible for 97 and 95% of models respectively. All non-feasible procedures occurred in ostia that underwent prophylactic “chimney” stenting. DC cannulation was challenging in 17% of models and was associated with a narrower SoV width (30 vs. 35 mm, p < 0.01), STJ width (28 vs. 32 mm, p < 0.05) and shorter STJ height (15 vs. 17 mm, p < 0.05). GC cannulation was challenging in 23% of models and was associated with narrower STJ width (28 vs. 32 mm, p < 0.05), smaller transcatheter-to-coronary distance (5 vs. 9.2 mm, p < 0.05) and a worse coronary-commissural overlap angle (14.3° vs. 25.6^o, p < 0.01). Advanced techniques to achieve GC cannulation were required in 22/64 (34%) of cases.

Conclusion

In this exploratory bench analysis, diagnostic angiography and PCI was feasible in almost all cases following ViV-TAVI with the ACURATE neo valve. Prophylactic coronary stenting, higher implantation, narrower aortic sinus dimensions and commissural misalignment were associated with an increased challenge of coronary cannulation.

Rationale, Definitions, Techniques, and Outcomes of Commissural Alignment in TAVR: From the ALIGN-TAVR Consortium

Given the expanding indications of transcatheter aortic valve replacement (TAVR) in younger patients with longer life expectancies, the ability to perform postprocedural coronary access represents a priority in their lifetime management. A growing body of evidence suggests that commissural (and perhaps coronary) alignment in TAVR impacts coronary access and valve hemodynamics as well as coronary flow and access after redo-TAVR. Recent studies have provided modified delivery system insertion and rotation techniques to obtain commissural alignment with available transcatheter heart valve devices. Moreover, patient-specific preprocedural planning and postprocedural imaging tools have been developed to facilitate and evaluate commissural alignment. Future efforts should aim to refine transcatheter heart valve and delivery system designs to make neocommissural alignment easier and more reproducible. The aim of this review is to present an in-depth insight of commissural alignment in TAVR, including its rationale, standardized definitions, technical steps, outcomes, and future directions.

Antithrombotic therapy after transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is a treatment option for patients with symptomatic severe aortic stenosis across the entire spectrum of surgical risk. TAVI conveys some risk for thrombotic complications, requiring antithrombotic drugs for their prevention. Bleeding events represent the major drawback of antithrombotic therapy, which should be carefully tailored over the individual patient's risk profile.

AREAS COVERED

This review aimed at exploring the rationale for the adoption of a tailored antithrombotic therapy after successful TAVI, with a description and analysis of common complications and their impact on therapy selection. In addition, we aimed at reviewing and discussing current knowledge in this area, with a main focus on the high-quality evidence supporting latest guideline recommendations. Finally, ongoing studies and future directions on antithrombotic therapy after TAVI were outlined.

EXPERT OPINION

Initial experience with antithrombotic therapy after TAVI was derived from percutaneous coronary intervention practice. Accruing evidence in the field led to the current monotherapy paradigm, which prioritizes oral anticoagulant and single antiplatelet therapy in patients with or without an established indication for long-term anticoagulation, respectively. Future studies will investigate the role of alternative antithrombotic strategies to improve clinical outcomes of TAVI patients by minimizing both thrombotic and bleeding complications.

Coronary access after TAVR with a cylindrical shaped valve: Learning from LOTUS

BACKGROUND/PURPOSE

Data on the feasibility of coronary access (CA) through above or outside of the cylindrical shaped-transcatheter heart valve (THV) are very limited. The aims of the present study were to assess the feasibility of CA after transcatheter aortic valve replacement (TAVR) with the LOTUS using multi detector computed tomography (MDCT) and the reliability of algorithm detecting unfavorable CA.

METHODS/MATERIALS

Post-TAVR MDCT of 41 patients with 82 coronary arteries were evaluated. The relationship and distance between the THV flame and sinotubular junction (STJ) and coronary ostia were assessed. Unfavorable CA was defined as the valve-to-STJ distance < 2-mm or the valve-to-coronary ostia distance < 2-mm if the THV flame was above STJ or coronary ostia.

RESULTS

MDCT-identified unfavorable CA was observed in 29.3% for the left coronary artery and 41.5% for the right coronary artery. In total, 53.7% of patients had at least one unfavorable CA and 14.6% of those had unfavorable CA for both left and right coronary artery. While patients underwent coronary angiography after TAVR, the success rates of selective coronary cannulation were significantly lower in patients with MDCT-identified unfavorable CA in comparison to those with favorable CA for left (20.0% vs. 100%, P = 0.002) and right coronary artery (0% vs. 100%, P < 0.001).

CONCLUSIONS

Future CA through above or outside of a cylindrical shaped THV may be challenging with a significant probability. Our algorithm identifying unfavorable CA using post-MDCT seems to be useful for estimating the risk of unsuccessful selective cannulation.