Commissural or Coronary Alignment for TAVR?: Align What and by How Much?

Impact of commissural versus coronary alignment on risk of coronary obstruction following transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) with commissural alignment aims to limit the risk of coronary occlusion and maintain good coronary access. However, due to coronary origin eccentricity within the coronary cusp, coronary-commissural overlap (CCO) may still occur. TAVI using coronary alignment, rather than commissural alignment, may further improve coronary access. To compare rates of CCO after TAVI using commissural versus coronary alignment methodology. Cardiac CT scans from 102 patients with severe (tricuspid) aortic stenosis referred for TAVI were analysed. Native cusp asymmetry and coronary eccentricity were defined and used to simulate TAVI using commissural versus coronary alignment. Rates of optimal coronary alignment (< 10° from cusp centre) and severe misalignment (< 15° from coronary-commissural overlap) were compared. Additionally, the impact of valve misalignment during implantation was assessed. The native right coronary artery (RCA) origin was 15.8° (9.5 to 24°) closer to the right coronary cusp/non-coronary cusp (RCC-NCC) commissure than the centre of the right coronary cusp. The native left coronary artery (LCA) origin was 4.5° (0 to 11.5°) closer to the left coronary cusp/non-coronary cusp (LCC-NCC) commissure than the centre of the left coronary cusp (p < 0.01). Compared to commissural alignment, coronary alignment doubled the proportion of optimally-aligned RCAs (62/102 [60.8%] vs. 31/102 [30.4%]; p < 0.001), without a significant change in optimal LCA alignment (62/102 [60.8% vs. 74/102 [72.6%]; p = 0.07). There were no cases of severe misalignment with either strategy. Simulating 15° of valve misalignment resulted in severe RCA compromise risk in 7/102 (6.9%) of commissural alignment cases, compared to none using coronary alignment. Fluoroscopic projection was similar with both approaches. Coronary alignment resulted in a 2-fold increase of optimal TAVI positioning relative to the RCA ostium when compared to commissural alignment without impacting the LCA. Use of coronary alignment rather than commissural alignment may improve coronary access after TAVI and is less sensitive to valve rotational error, particularly for the right coronary artery.

Commissural vs Coronary Alignment to Avoid Coronary Overlap With THV-Commissure in TAVR: A CT-Simulation Study

BACKGROUND

Coronary alignment is proposed as an alternative to commissural alignment for reducing coronary overlap during transcatheter aortic valve replacement (TAVR). However, largescale studies are lacking.

OBJECTIVES

This study aimed to determine the incidence of coronary overlap with commissural vs coronary alignment using computed tomography (CT) simulation in patients undergoing TAVR evaluation.

METHODS

In 1,851 CT scans of native aortic stenosis patients undergoing TAVR evaluation (April 2018 to December 2022),virtual valves simulating commissural and coronary alignment were superimposed on axial aortic root images. Coronary overlap was assessed based on the angular gap between coronary artery origin and the nearest transcatheter heart valve commissure, categorized as severe (≤15°), moderate (15°-30°), mild (30°-45°), and no-overlap (45°-60°).

RESULTS

The overall incidence of moderate/severe and severe overlap with either coronary artery remained rare with either coronary or commissural alignment (coronary 0.52% left, 0.52% right; commissural 0.30% left, 3.27% right). Comparing techniques, coronary alignment reduced moderate/severe overlap only for the right coronary artery (0.38% vs 2.97%; P <0.0001). For the left coronary artery, both techniques showed similar moderate/severe overlap, but commissural alignment had significantly higher no-overlap rates (91.1% vs 84.9%; P < 0.0001). Fluoroscopic angle during valve deployment was strongly correlated between commissural and coronary alignment (r = 0.80; P < 0.001).

CONCLUSIONS

Using CT simulation, the incidence of coronary overlap with transcatheter heart valve-commissure is rare with commissural alignment. Coronary alignment reduced right coronary overlap, whereas commissural alignment had higher rates of no left coronary overlap. Coronary alignment should be reserved only when commissural alignment results in severe coronary overlap.

The Incidence, Impact, and Techniques of Commissural Alignment in Transcatheter Aortic Valve Implantation: A Review

In current clinical practice, commissural alignment of the transcatheter heart valve (THV) during transcatheter aortic valve implantation (TAVI) is seldom achieved. Orientation of the THV within the aortic root and the subsequent influence upon leaflet haemodynamic function, coronary blood flow, and ease of access to the coronary ostia are gaining significant interest. Herein, we review the incidence and clinical implications of commissural misalignment in TAVI and offer thorough descriptions of how optimal alignment can be achieved with several different contemporary THV devices.

TAVR Interventions and Coronary Access: How to Prevent Coronary Occlusion

Due to technological advancements during the past 20 years, transcatheter aortic valve replacements (TAVRs) have significantly improved the treatment of symptomatic and severe aortic stenosis, significantly improving patient outcomes. The continuous evolution of transcatheter valve models, refined imaging planning for enhanced accuracy, and the growing expertise of technicians have collectively contributed to increased safety and procedural success over time. These notable advancements have expanded the scope of TAVR to include patients with lower risk profiles as it has consistently demonstrated more favorable outcomes than surgical aortic valve replacement (SAVR). As the field progresses, coronary angiography is anticipated to become increasingly prevalent among patients who have previously undergone TAVR, particularly in younger cohorts. It is worth noting that aortic stenosis is often associated with coronary artery disease. While the task of re-accessing coronary artery access following TAVR is challenging, it is generally feasible. In the context of valve-in-valve procedures, several crucial factors must be carefully considered to optimize coronary re-access. To obtain successful coronary re-access, it is essential to align the prosthesis with the native coronary ostia. As part of preventive measures, strategies have been developed to safeguard against coronary obstruction during TAVR. One such approach involves placing wires and non-deployed coronary balloons or scaffolds inside an at-risk coronary artery, a procedure known as chimney stenting. Additionally, the bioprosthetic or native aortic scallops intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) procedure offers an effective and safer alternative to prevent coronary artery obstructions. The key objective of our study was to evaluate the techniques and procedures employed to achieve commissural alignment in TAVR, as well as to assess the efficacy and measure the impact on coronary re-access in valve-in-valve procedures.

Emerging transcatheter heart valve technologies for severe aortic stenosis

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is the standard of care for selected patients with severe aortic stenosis, irrespective of the surgical risk. Over the last two decades of TAVI practice, multiple limitations were identified. In addition, the extension of TAVI into a wider patient spectrum created new challenges.

AREAS COVERED

This review provides an overview of emerging transcatheter heart valves (THVs) beyond the approved contemporary THVs for the treatment of aortic stenosis.

EXPERT OPINION

The incidence of degenerative aortic stenosis is expected to increase with more aging of the population. Therefore, TAVI needs to meet this increase in the number of patients indicated for aortic valve replacement alongside a wide and complex anatomical variability. An increasing number of Aortic THVs are available in the market. This includes upgraded iterations of contemporary devices and innovative devices developed by emerging manufacturers. The new devices aim for the reduction or elimination of undesirable outcomes like paravalvular leakage and conduction disturbances requiring permanent pacemaker implantation. Alternatively, emerging THVs should provide feasibility regarding yet unproven TAVI indications like Bicuspid aortic valve, aortic regurgitation, or very large anatomy. Furthermore, some of the emerging THVs are designed to tackle the long-term durability issue of biological valves.

Transcatheter heart valve commissural alignment: an updated review

Transcatheter aortic valve replacement (TAVR) indications recently extended to lower surgical risk patients with longer life expectancy. Commissural alignment (CA) is one of the emerging concepts and is becoming one of the cornerstones of the TAVR procedure in a patient with increased longevity. Indeed, CA may improve transcatheter heart valve (THV) hemodynamics, future coronary access, and repeatability. The definition of CA has been recently standardized by the ALIGN-TAVR consortium using a four-tier scale based on CT analysis. Progress has been made during the index TAVR procedure to optimize CA, especially with self-expandable platforms. Indeed, specific delivery catheter orientation, THV rotation, and computed-tomography-derived views have been proposed to achieve a reasonable degree of CA. Recent data demonstrate feasibility, safety, and a significant reduction in coronary overlap using these techniques, especially with self-expandable platforms. This review provides an overview of THV CA including assessment methods, alignment techniques during the index TAVR procedure with different THV platforms, the clinical impact of commissural misalignment, and challenging situations for CA.

Aortic Annulus S-Curve: Implications for Transcatheter Aortic Valve Replacement and Related Procedures, Part 1

Most transcatheter aortic valve replacement-related procedures (eg, transcatheter aortic valve replacement implantation depth, commissural alignment, coronary access, bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction, paravalvular leak closure) require an optimal fluoroscopic viewing angle located somewhere along the aortic annulus S-curve. Chamber views, coronary cusp and coronary anatomy, can be understood along the aortic annulus S-curve. A better understanding of the optimal fluoroscopic viewing angles along the S-curve may translate into increased operator confidence and improved safety and efficacy while reducing procedural time, radiation dose, contrast volume, and complication rates.

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.