Preventing Coronary Obstruction During Transcatheter Aortic Valve Replacement: From Computed Tomography to BASILICA

Electrosurgery in Structural Heart Interventions

Electrosurgery has emerged as a groundbreaking tool in the field of structural cardiac interventions, revolutionizing the approach to complex cardiac conditions. This review delves into the core principles, procedural techniques, outcomes, and potential challenges associated with various electrosurgical procedures within the realm of structural cardiology. Five key electrosurgical procedures performed in complex structural interventions are highlighted in this review. They are the Transcaval Access, BASILICA, LAMPOON, ELASTIC/ELASTA-Clip, and SESAME procedures. While these electrosurgery procedures hold promise and have demonstrated positive outcomes, their technical intricacies, patient selection criteria, and the need for further research remain important considerations. As technology continues to evolve and more data becomes available, electrosurgery is poised to continue shaping the landscape of cardiac care, offering minimally invasive alternatives, and improving patient outcomes in complex structural cardiac interventions.

Valve-in-Valve-in-Valve

In the case of the degeneration of surgical aortic valve replacement (SAVR), the transcatheter aortic valve implantation (TAVI) has become the standard. However, these valves are also susceptible to deterioration. In such instances, a new TAVI implantation may be considered. We present the case of a patient with a SAVR who underwent two TAVI procedures, spaced 8 years apart. We discuss important practical aspects, including the risk of coronary obstruction and the final valve diameter.

Cardiac computed tomography post-transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is performed to treat aortic stenosis and is increasingly being utilised in the low-to-intermediate-risk population. Currently, attention has shifted towards long-term outcomes, complications and lifelong maintenance of the bioprosthesis. Some patients with TAVR in-situ may develop significant coronary artery disease over time requiring invasive coronary angiography, which may be problematic with the TAVR bioprosthesis in close proximity to the coronary ostia. In addition, younger patients may require a second transcatheter heart valve (THV) to 'replace' their in-situ THV because of gradual structural valve degeneration. Implantation of a second THV carries a risk of coronary obstruction, thereby requiring comprehensive pre-procedural planning. Unlike in the pre-TAVR period, cardiac CT angiography in the post-TAVR period is not well established. However, post-TAVR cardiac CT is being increasingly utilised to evaluate mechanisms for structural valve degeneration and complications, including leaflet thrombosis. Post-TAVR CT is also expected to have a significant role in risk-stratifying and planning future invasive procedures including coronary angiography and valve-in-valve interventions. Overall, there is emerging evidence for post-TAVR CT to be eventually incorporated into long-term TAVR monitoring and lifelong planning.

Beyond Static Planning: Computational Predictive Modeling to Avoid Coronary Artery Occlusion in TAVR

BACKGROUND

Coronary artery occlusion (CO) during transcatheter aortic valve replacement (TAVR) is a devastating complication. The objective of this study was to assess the clinical impact of a computational predictive modeling algorithm for CO during TAVR planning.

METHODS

From January 2020 to December 2022, 116 patients (7.6%) who underwent TAVR evaluation were deemed to be at increased risk of CO on the basis of traditional criteria. Patients underwent prospective computational modeling (DASI Simulations) to assess their risk of CO during TAVR; procedural modifications and clinical results were reviewed retrospectively.

RESULTS

Of the 116 patients at risk for CO by traditional methodology, 53 had native aortic valve stenosis (45.7%), 47 had undergone previous surgical AVR (40.5%), and 16 had undergone previous TAVR (13.8%). Transcatheter valve choice, size, or implantation depth was modeled for all patients. Computational modeling predicted an increased risk of CO in 39 of 116 (31.9%) patients. Within this subcohort, 29 patients proceeded with TAVR. Procedural modifications to augment the risk of CO included bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (n = 10), chimney coronary stents (n = 8), and coronary access without stents (n = 3). There were no episodes of coronary artery compromise among patients after TAVR, either for those predicted to be at high risk of CO (with procedural modifications) or those predicted to be at low risk (standard TAVR).

CONCLUSIONS

The use of preoperative simulations for TAVR in patient-specific geometry through computational predictive modeling of CO is an effective enhancement to procedure planning.

Coronary Artery Obstruction After Transcatheter Aortic Valve Implantation: Past, Present, and Future

Coronary obstruction (CO) is a rare but critical complication of transcatheter aortic valve implantation. It is associated with significant morbidity and mortality. This comprehensive review elucidates the evolving landscape of CO risk assessment and management strategies in the contemporary era of transcatheter aortic valve implantation. Drawing upon recent advances in computed tomography angiography, we delve into the nuanced evaluation of anatomic parameters crucial for predicting CO risk. Furthermore, this review explores the utility of interventional and surgical techniques, including chimney stenting and leaflet modification systems, in mitigating CO complications. In summary, this review serves as a practical guide for clinicians navigating the complexities of CO prevention and management in the evolving landscape of transcatheter aortic valve implantation, with the goal of optimizing patient outcomes and ensuring procedural success.

Transcatheter Aortic Valve Implantation for Severe Chronic Aortic Regurgitation

Transcatheter aortic valve implantation (TAVI) has revolutionised the management of aortic valve disease, offering a less invasive alternative to traditional surgical valve replacement for severe aortic stenosis (AS). TAVI for pure aortic regurgitation (AR) is less well established, and, in fact, it was previously labelled as a relative contraindication. However, TAVI has been utilised for selected cases of pure or predominant AR. The primary limitations regarding the use of TAVI in AR are related to the absence of anatomical factors seen in patients with AS that have contributed to the safe and stable functioning of current-generation prostheses. These include aortic root dilatation, mobile valve leaflets and labile blood pressure within the aortic root, which may further increase the risk of valve migration and periprosthetic leak after deployment. Furthermore, patients with AR have more heterogeneous aortic root anatomies when compared to the population of patients with calcific or degenerative AS. This review article describes the current evidence for the off-label use of TAVI in pure AR and the various clinical syndromes associated with AR where there may be specific challenges in the application of TAVI.

Case Report: Double chimney in valve-in-valve procedures for high-risk coronary obstruction

The chimney technique has been utilized to minimize the risk of coronary artery obstruction during valve-in-valve procedures. Here, we present a case involving an 89-year-old female patient with low coronary ostia, severe aortic regurgitation, and intractable heart decompensation caused by degenerated aortic bioprosthesis. The patient underwent a successful transcatheter aortic valve implantation procedure using the chimney technique in both coronary ostia.

Aortic root geometry following composite valve graft implantation: Implications for future valve-in-valve procedures

OBJECTIVES

Biological composite valve grafts (CVGs) are being performed more frequently, which increases the need for interventions treating bioprosthetic valve failure. The feasibility of valve-in-valve procedures in this population is uncertain. This study aimed to assess changes in aortic root geometry and coronary height following CVG implantation to better understand future interventions.

METHODS

We retrospectively identified 64 patients following bioprosthetic CVG replacement with pre- and postoperative computed tomography angiography. Root assessment was conducted as in preprocedural transcatheter aortic valve evaluation using a virtual valve simulation.

RESULTS

In 64 patients (age, 67.6 ± 9.3 years; 76.6% men) the preoperative coronary height was 14.3 ± 6.8 mm for the left coronary artery (LCA) and 17.9 ± 5.9 mm for the right coronary artery (RCA), which significantly decreased after CVG implantation, with 8.7 ± 4.4 mm for the LCA and 11.3 ± 4.4 mm for the RCA (P < .001). The virtual valve-to-coronary distances measured 4.0 ± 1.3 mm (LCA) and 4.6 ± 1.4 mm (RCA). Overall, 59.4% (n = 38) of patients with bio-CVGs would have been at risk for coronary obstruction, 29.7% (n = 19) for LCA, 10.9% (n = 7) for RCA, and 18.8% (n = 12) for combined LCA and RCA.

CONCLUSIONS

Coronary height significantly decreased following CVG implantation. The majority of patients after bio-CVG were at a potential risk for coronary obstruction in future valve-in-valve procedures. Further studies are needed to identify the best possible technique for coronary reimplantation and other measures to diminish the risk for future coronary obstruction in this population.

Effect of leaflet laceration on transcatheter aortic valve replacement fluid mechanics and comparison with surgical aortic valve replacement

BACKGROUND

Leaflet thrombosis after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) may be caused by blood flow stagnation in the native and neosinus regions. To date, aortic leaflet laceration has been used to mitigate coronary obstruction following TAVR; however, its influence on the fluid mechanics of the native and neosinus regions is poorly understood. This in vitro study compared the flow velocities and flow patterns in the setting of SAVR vs TAVR with and without aortic leaflet lacerations.

METHODS

Two valves, (23-mm Perimount and 26-mm SAPIEN 3; Edwards Lifesciences) were studied in a validated mock flow loop under physiologic conditions. Neosinus and native sinus fluid mechanics were quantified using particle image velocimetry in the left and noncoronary cusp, with an increasing number of aortic leaflets lacerated or removed.

RESULTS

Across all conditions, SAVR had the highest average sinus and neosinus velocities, and this value was used as a reference to compare against the TAVR conditions. With an increasing number of leaflets lacerated or removed with TAVR, the average sinus and neosinus velocities increased from 25% to 70% of SAVR flow (100%). Diastolic velocities were substantially augmented by leaflet laceration. Also, the shorter frame of the SAVR led to higher flow velocities compared with the longer frame of the TAVR, even after complete leaflet removal.

CONCLUSIONS

Leaflet laceration augmented TAVR native and neosinus flow fields, approaching that of SAVR. These findings may have potential clinical implications for the use of single or multiple leaflet lacerations to reduce leaflet thrombosis and thus potentially improve TAVR durability.

Computed tomography to guide transcatheter aortic valve implantation

Since its introduction in 2022, transcatheter aortic valve implantation (TAVI) has revolutionized the treatment and prognosis of patients with aortic stenosis. Robust clinical trial data and a wealth of scientific evidence support its efficacy and safety. One of the key factors for success of the TAVI procedure is careful preprocedural planning using imaging. Computed tomography (CT) has developed into the standard imaging method for comprehensive patient assessment in this context. Suitability of the femoral and iliac arteries for transfemoral access, exact measurement of aortic annulus size and geometry as the basis for prosthesis selection, quantification of the spatial relationship of the coronary ostia to the aortic annular plane, and identification of optimal fluoroscopic projection angles for the implantation procedure are among the most important information that can be gained from preprocedural CT. Further research is aimed at improving risk stratification, for example, with respect to annular perforation, periprosthetic aortic regurgitation, and need for postprocedural implantation of a permanent pacemaker.

Electrocautery-assisted re-entry to resolve bilateral aorto-ostial chronic total occlusions due to leaflet obstruction following transcatheter aortic valve replacement

Coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve replacement (TAVR). While urgent percutaneous coronary intervention has been described in cases of acute occlusion, little is known about the interventional management of obstruction once it has occurred in the chronic setting. We describe a case in which electrocautery-assisted re-entry was successfully utilized to manage the right coronary artery and left main chronic total occlusion due to leaflet-induced coronary artery obstruction after TAVR.

TAVI after More Than 20 Years

It has been more than 20 years since the first in man transcatheter aortic valve intervention (TAVI), and during this period we have witnessed an impressive evolution of this technique, with an extension of its use from non-operable patients to high-, intermediate- and even low-risk patients with aortic stenosis, and with a decrease in the incidence of complications. In this review, we discuss the evaluation of patients before TAVI, the procedure and the changes it has seen over time, and we present the current main complications and challenges of TAVI.

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.

Aortic valve reintervention after transcatheter aortic valve replacement

BACKGROUND

Despite the rapid adoption of transcatheter aortic valve replacement (TAVR), there are scant data regarding aortic valve reintervention after initial TAVR.

METHODS

Between 2011 and 2019, 1487 patients underwent a TAVR at the University of Michigan. Among these, 24 (1.6%) patients required an aortic valve reintervention. Additionally, 4 patients who received a TAVR at another institution underwent a valve reintervention at our institution. We retrospectively reviewed these 28 patients.

RESULTS

The median age was 72 years, 36% were female and 86% of implanted TAVR devices were self-expandable. The leading indications for reintervention were structural valve degeneration (39%) and paravalvular leak (36%). The cumulative incidence of aortic valve reintervention was 4.6% at 8 years. Most (71%) were deemed unsuitable for repeat TAVR because of the need for concurrent cardiac procedures (50%), unfavorable anatomy (45%), or endocarditis (10%). TAVR valve explant was associated with frequent concurrent procedures, consisting of aortic repair (35%), mitral repair/replacement (35%), tricuspid repair (25%), and coronary artery bypass graft (20%). Seventy-one percent of aortic procedures were unplanned but proved necessary because of severe adhesion of the devices to the contacting tissue. There were 3 (15%) in-hospital mortalities in the TAVR valve explant group, whereas there was no mortality in the repeat TAVR group.

CONCLUSIONS

Repeat TAVR procedure was frequently not feasible because of unfavorable anatomy and/or the need for concurrent cardiac procedures. Careful assessment of TAVR procedure repeatability should be weighed at the initial TAVR workup especially in younger patients who are expected to require a valve reintervention.

Contemporary issues and lifetime management in patients underwent transcatheter aortic valve replacement

Latest clinical trials have indicated favorable outcomes following transcatheter aortic valve replacement (TAVR) in low surgical risk patients with severe aortic stenosis. However, there are unanswered questions particularly in younger patients with longer life expectancy. While current evidence are limited to short duration of clinical follow-up, there are certain factors which may impair patients clinical outcomes and quality-of-life at long-term. Contemporary issues in the current TAVR era include prosthesis-patient mismatch, heart failure hospitalization, subclinical thrombosis, future coronary access, and valve durability. In this review, the authors review available evidence and discuss each remaining issues and theoretical treatment strategies in lifetime management of TAVR patients.

Transcatheter Electrosurgery: A Narrative Review

Transcatheter electrosurgery describes the ability to cut and traverse tissue, at a distance, without an open surgical field and is possible using either purpose-built or off-the-shelf devices. Tissue traversal requires focused delivery of radiofrequency energy to a guidewire tip. Initially employed to cross atretic pulmonary valves, tissue traversal has enabled transcaval aortic access, recanalization of arterial and venous occlusions, transseptal access, and many other techniques. To cut tissue, the selectively denuded inner curvature of a kinked guidewire (the Flying-V) or a single-loop snare is energized during traction. Adjunctive techniques may complement or enable contemporary transcatheter procedures, whereas myocardial slicing or excision of ectopic masses may offer definitive therapy. In this contemporary review we discuss the principles of transcatheter electrosurgery, and through exemplary clinical applications highlight the range of therapeutic options offered by this versatile family of procedures.

Cardiac arrest caused by coronary occlusion during transcatheter aortic valve implantation: a unique cause

Coronary artery occlusion (CAO) is a rare but life-threatening complication of transcatheter aortic valve implantation (TAVI). The mechanism of CAO is the displacement of the native calcified valve leaflet over the coronary ostium. Here, we report on a woman who experienced sudden cardiac arrest and abrupt CAO during TAVI, which was caused by two different original obstructions, a rupture of aortic plaque or a partial tear of the aortic intima blocking the upper 2/3 of the left main trunk (LMT) ostium, and the transcatheter heart valve (THV) blocking the lower 1/3 of the LMT ostium. She was eventually successfully treated with the chimney stenting technique. Aortography other than coronary angiography was used to ascertain CAO. In patients presenting with abrupt cardiac arrest or cardiogenic shock with LMT occlusion, there must be prompt identification, and the causes of CAO may be various and rare. The identification of CAO relies not only on CAG but also on aortography, especially if the locations and origins of obstructions are special. Supportive therapy with an attempt at percutaneous revascularization is necessary. Pre-procedural assessment is crucial prior to TAVI interventions. In cases with high risk of CAO, upfront coronary artery protection can be provided.

Leaflet modification or chimney stenting in patients at risk for coronary artery obstruction in valve-in-valve procedure for a failed surgical bioprosthetic aortic valve

Valve-in-valve transcatheter aortic valve replacement (VIV-TAVR) for a degenerated surgical aortic bioprosthesis is a well-established treatment modality but carries an increased risk of coronary artery obstruction (CAO) with potentially catastrophic consequences. Both chimney stenting and leaflet modification by BASILICA (Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Obstruction) are increasingly employed and can be highly effective means of preventing CAO. Using a case report, in which both strategies were utilized, as a platform for detailed discussion, we address the indications, contraindications, and relative merits of each technique in the prevention of CAO.

First-in-Human Dedicated Leaflet Splitting Device for Prevention of Coronary Obstruction in Transcatheter Aortic Valve Replacement

BACKGROUND

Coronary artery obstruction is a life-threatening complication of transcatheter aortic valve replacement (TAVR) procedures. Current preventive strategies are suboptimal.

OBJECTIVES

The aim of this study was to describe bench testing and clinical experience with a novel device that splits valve leaflets that are at risk for causing coronary obstruction after TAVR, allowing normal coronary flow.

METHODS

The ShortCut device was initially tested in vitro and preclinically in a porcine model for functionality and safety. The device was subsequently offered to patients at elevated risk for coronary obstruction. Risk for coronary obstruction was based on computed tomography-based anatomical characteristics. Procedure success was determined as patient survival at 30 days with a functioning new valve, without stroke or coronary obstruction.

RESULTS

Following a successful completion of bench testing and preclinical trial, the device was used in 8 patients with failed bioprosthetic valves (median age 81 years; IQR: 72-85 years; 37.5% man) at 2 medical centers. A total of 11 leaflets were split: 5 patients (63.5%) were considered at risk for left main obstruction alone, and 3 patients (37.5%) were at risk for double coronary obstruction. All patients underwent successful TAVR without evidence of coronary obstruction. All patients were discharged from the hospital in good clinical condition, and no adverse neurologic events were noted. Procedure success was 100%.

CONCLUSIONS

Evaluation of the first dedicated transcatheter leaflet-splitting device shows that the device can successfully split degenerated bioprosthetic valve leaflets. The procedure was safe and successfully prevented coronary obstruction in patients at risk for this complication following TAVR.

Role of Multimodality Imaging in Transcatheter Structural Interventions

Cardiac imaging is the backbone for safe and optimal transcatheter structural interventions. Transthoracic echocardiogram is the initial modality to assess valvular disorders, while transesophageal echocardiogram is best to delineate the mechanism of valvular regurgitation, preprocedural assessment for transcatheter edge-to-edge repair, and for intraprocedural guidance. Cardiac computed tomography is the modality of choice for assessing calcifications, maneuvering multiplaner reconstruction of different cardiac structures, preprocedural planning for various transcatheter valve replacement, and assessing for hypoattenuated leaflet thickening and reduced leaflet motion. Cardiac magnetic resonance imaging is best known for most accurate volumetric assessment of valvular regurgitation and chamber size quantification. Cardiac positron emission tomography is the only modality that could assess active infection through using fluorine 18 fluorodeoxyglucose radiotracer.

Aortic valve leaflet disruption techniques in transcatheter aortic valve replacement

With continued technological advancement and technical improvement of transcatheter aortic valve replacement (TAVR), it has become a desirable treatment option for aortic valve stenosis. Its minimally invasive approach compared to surgical aortic valve replacement offers the treatment to a broader patient population, mainly non-surgical candidates. A feared complication of TAVR is the occlusion of coronary artery ostium by the native aortic valve leaflet due to its displacement by the expanded transcatheter valve. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) is a technique developed to mitigate this risk by creating a lengthwise laceration of the left and/or right aortic valve leaflets prior to TAVR. Patient outcomes following TAVR with BASILICA have been promising. Meticulous preoperative examination, patient selection, and hemodynamic management are imperative. With continued refinement, BASILICA may further expand the application of TAVR to patients at high risk for coronary occlusion associated with the procedure.

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.

Transcatheter Aortic Valve Implantation for Bioprosthetic Valve Failure: Placement of Aortic Transcatheter Valves 3 Aortic Valve-in-Valve Study

Background

Transcatheter aortic valve implantation is safe and effective for high-risk patients with bioprosthetic valve failure (BVF) but has not been studied in low- and intermediate-risk patients. One year outcomes of the PARTNER 3 Aortic Valve-in-valve (AViV) Study were evaluated.

Methods

This prospective, single-arm, multicenter study enrolled 100 patients from 29 sites with surgical BVF. The primary endpoint was a composite of all-cause mortality and stroke at 1 year. The key secondary outcomes included mean gradient, functional capacity, and rehospitalization (valve-related, procedure-related, or heart failure related).

Results

A total of 97 patients underwent AViV with a balloon-expandable valve from 2017 to 2019. Patients were 79.4% male with a mean age of 67.1 years and Society of Thoracic Surgeons score of 2.9%. The primary endpoint occurred in 2 patients (2.1%) who had strokes; there was no mortality at 1 year. Five patients (5.2%) had valve thrombosis events, and 9 patients (9.3%) had rehospitalizations, including 2 (2.1%) for strokes, 1 (1.0%) for heart failure, and 6 (6.2%) for aortic valve reinterventions (3 explants, 3 balloon dilations, and 1 percutaneous paravalvular regurgitation closure). From baseline to 1 year, New York Heart Association class III/IV decreased from 43.3% to 4.5%, mean gradient from 39.1 ± 18.2 mm Hg to 19.7 ± 7.6 mm Hg, and ≥moderate aortic regurgitation from 41.1% to 1.1%.

Conclusions

AViV with a balloon-expandable valve improved hemodynamic and functional status at 1 year and can provide an additional therapeutic option in selected low- or intermediate-risk patients with surgical BVF, although longer term follow-up is necessary.

Coronary Artery Disease in Patients Undergoing Transvalvular Aortic Valve Implantation

Coronary artery disease (CAD) is common in patients with severe aortic stenosis. With the advent of transcatheter aortic valve implantation (TAVI) as a therapeutic option, management of CAD in such patients has undergone a revolution. Younger patients are now candidates for treatment, and have a greater life-time probability of requiring post-TAVI coronary access. Considerations include pre-procedural assessment and revascularisation, procedural planning to avoid coronary obstruction as well as optimisation of post-procedural coronary access. The authors review the challenges of managing CAD in TAVI patients, shed light on the evidence base, and provide guidance on how to optimise management.

Transcatheter Aortic Valve Replacement in Failed Transcatheter Bioprosthetic Valves

Transcatheter aortic valve replacement (TAVR) is increasingly being performed in younger and lower surgical risk patients. Given the longer life expectancy of these patients, the bioprosthetic valve will eventually fail, and aortic valve reintervention may be necessary. Although currently rare, redo-TAVR will likely increase in the future as younger patients are expected to outlive their transcatheter bioprosthesis. This review provides a contemporary overview of the indications, procedural planning, implantation technique, and outcomes of TAVR in failed transcatheter bioprosthetic aortic valves.

New adverse coronary events in valve-in-valve TAVR and native TAVR—A 2-year matched cohort

Objective

To assess the incidence of new adverse coronary events (NACE) following transcatheter aortic valve replacement (TAVR) and valve-in-valve TAVR (ViV-TAVR).

Background

ViV-TAVR is an accepted treatment for degenerative prostheses among patients with high surgical-risk. TAVR studies have suggested an increased risk of coronary artery obstruction and flow stasis causing thrombus formation. Whether contemporary ViV-TAVR is associated with higher rate of coronary events compared to TAVR is unknown.

Methods

We used data from 1,224 TAVR patients between 2016 and 2021. We propensity-matched patients following ViV-TAVR and TAVR by significant predictors to overcome confounders in patients' baseline characteristics and procedural factors.

Results

The matched population included 129 patients in each group. In line with prior reports, there was a higher in-hospital coronary artery obstruction rate with ViV-TAVR (3.1 vs. 1.6%; p = 0.23). Despite this, 2-year cumulative NACE rates were similar between groups (4.7 vs. 6.2%, respectively, p = 0.79), with no difference between its components: myocardial infarction (MI) (p = 0.210), unplanned coronary catheterization (p = 0.477), or coronary artery bypass grafting (CABG) (p = 0.998). Moreover, hypoattenuated leaflets thickening (HALT) at 30-day CT was observed in nearly a quarter of the patients with no difference between groups (23.9 vs. 23.1%, HR 1.02, 95% CI 0.50–1.28, p = 0.872). The progression rate of the coronary artery calcium score (CACS), assessed in a third of patients, was similar between groups (p log-rank = 0.468, 95% CI 0.12–1.24). Low coronary artery height was an unfavorable predictor for in-hospital coronary obstruction and 2-year NACE rate (HR 1.20 and HR 1.25, p = 0.001 and p < 0.0001, respectively).

Conclusion

At 2-year follow-up, ViV-TAVR was not associated with a higher rate of myocardial infarction, unplanned catheterization, coronary artery bypass grafting, or hypoattenuated leaflet thickening.

Use of Electrosurgery in Interventional Cardiology

Transcatheter electrosurgery is a versatile tool that can be used to cut cardiac tissue without the need for a sternotomy, cardiopulmonary bypass, and cardioplegia. With adequate imaging and suitable anatomy, any cardiac tissue can be cut. Thus, transcatheter electrosurgery can provide bespoke therapies for complex patients who often have no other good treatment options. In this review, we will discuss the common applications for electrosurgical tissue traversal and laceration, including transcaval access, BASILICA, LAMPOON, and ELASTA-Clip, summarizing the evidence and the key technical steps for each.

Interventional echocardiography: Opportunities and challenges in an emerging field

The growth of transcatheter structural heart disease interventions has created a subspecialty of interventional imagers who focus on preprocedural planning and the periprocedural guidance of these complex cases. In particular interventional imagers who focus on periprocedural guidance have developed a specific expertise in interventional transesophageal echocardiography (iTEE). This nascent field has challenges in training, reimbursement, and occupational hazards which are unique to this field. This review encompasses the evolution of iTEE, current challenges, and future opportunities.

Expanding our horizons for the use of transcatheter self-expanding valves: what does the future hold?

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is an established alternative to aortic valve surgery in patient with severe aortic valve stenosis. As interventionalists are pushing towards treatment of patients with lower risk profile with a wide range of anatomies, contemporary transcatheter heart valves (THV) should offer an excellent performance in terms of residual gradient, rate of pacemaker and perivalvular leak.

AREAS COVERED

Self-expandable (SE) valve offer a valid alternative to balloon-expandable (BE) valves, nevertheless comparative trials suggest a better outcome of patients treated with BE over SE platforms. New generation SE valves offer an excellent outcome in terms of procedural safety, however implementations in valve design and performance are required to reach the BE valves performance.

EXPERT COMMENTARY

in the near future, new devices should be able to obtain optimal results with a negligible rate of complications. Developments in the design of the delivery system together with refinements in valve technology are desirable to achieve results which are comparable to surgical aortic valve replacement.

Risk of Coronary Obstruction During Redo-TAVR in Patients With Bicuspid Versus Tricuspid Aortic Valve Stenosis

OBJECTIVES

The aim of this study was to investigate the risk of coronary obstruction during redo-transcatheter aortic valve replacement (TAVR) within a previously implanted self-expanding valve in bicuspid aortic valve (BAV) versus tricuspid aortic valve (TAV) stenosis.

BACKGROUND

The prevalence of BAV in TAVR patients is expected to increase as the indication expands; however, no study has investigated the risk of coronary obstruction for future redo-TAVR in these patients.

METHODS

Computed tomography (CT) simulation analysis was performed in 86 type 0 BAV, 70 type 1 BAV, and 132 TAV patients who underwent TAVR with 1 VenusA-Valve (Venus Medtech) between January 2014 and December 2019.

RESULTS

CT-identified risk of coronary obstruction during redo-TAVR was observed in 36.1% of patients for the left coronary ostium (LCO) and 27.8% of patients for the right coronary ostium (RCO); however, the incidences were significantly lower in the type 0 BAV group than in the type 1 BAV or TAV group (for LCO: OR: 1.00 [reference] vs OR: 2.49; 95% CI: 1.24-5.01 vs OR: 2.60; 95% CI: 1.40-4.81; for RCO: OR: 1.00 [reference] vs OR: 2.14; 95% CI: 1.02-4.48 vs OR: 1.97; 95% CI: 1.02-3.80). The leaflet laceration technique may be unfeasible to improve coronary flow in 61.5% of the threatened LCOs and 58.8% of the threatened RCOs during redo-TAVR. The percentages were significantly or numerically lower in the type 0 BAV group than other groups (for LCO: 26.3% vs 62.1% vs 73.2%; P overall = 0.001; for RCO: 43.8% vs 65.2% vs 61.0%; P overall = 0.374).

CONCLUSIONS

Differences in anatomical features may impact the feasibility of future redo-TAVR. Type 0 BAV anatomy was associated with the lower incidence of CT-identified risk of coronary obstruction during redo-TAVR, and the leaflet laceration technique may be more feasible to ensure coronary flow in this population.

Valve-in-valve Transcatheter Aortic Valve Replacement for Failed Surgical Valves and Adjunctive Therapies

While redo surgical aortic valve replacement has traditionally been the gold standard for the treatment of failed surgical valves, valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) has arisen as a viable, less invasive option with the potential for improved short-term morbidity and mortality. Retrospective registry data regarding ViV TAVR outcomes have been encouraging, with excellent 1-year mortality, and sustained valve performance and quality of life improvement out to 3 years. Operators must be comfortable with CT analysis for procedural planning, and be able to identify and troubleshoot patients who are at risk for coronary obstruction and patient prosthesis mismatch. The authors provide a review of clinical outcomes associated with ViV TAVR, procedural planning recommendations, and strategies to overcome technical challenges that can occur during ViV TAVR.

2021. The year in review. Structural heart interventions

Since the beginning of 2020, the corona virus (COVID-19) pandemic redefined in many ways the practice of cardiology, research and cardiology conferences. Virtual conferences replaced most major in-person venues. The number of “elective” structural heart interventions declined and clinical research endured major setbacks in regards to academic and industry-sponsored clinical trials. In this review, we attempt to provide a broad overview of the field for general and interventional cardiologists with a specific interest in structural heart interventions.

Risk Assessment of Coronary Obstruction During Transcatheter Aortic Valve Replacement: Insights From Post-BASILICA Computed Tomography

OBJECTIVES

The aim of this study was to examine the predictive value of preprocedural computed tomography (CT)-based risk stratification of coronary obstruction during transcatheter aortic valve replacement (TAVR) on the basis of geometric measurements on postprocedural CT.

BACKGROUND

Proper patient selection for additional procedures to prevent coronary obstruction during TAVR has not been adequately evaluated.

METHODS

Pre- and postprocedural computed tomographic scans of 28 patients treated using bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) and TAVR were analyzed. Using the postprocedural computed tomographic images, threatened coronary obstruction (TCO) was defined as: 1) ostial obstruction (adherence of the transcatheter heart valve [THV] to the coronary ostium with leaflet extension above the ostium); and/or 2) sinus sequestration (THV adherence to the sinotubular junction [STJ] with leaflet extension above the STJ) and was substratified into complete and incomplete types.

RESULTS

A total of 51 leaflets were evaluated (88% surgical tissue valves) after excluding leaflets not visible on CT (n = 5). On postprocedural CT, complete TCO was observed in 25.4% (13 of 51 leaflets). On preprocedural CT, leaflets were at high risk for complete TCO (incidence 53%) if the virtual THV-to-coronary distance (VTC) was <3.0 mm, or if the virtual THV-to-STJ distance (VTSTJ) was <1.0 mm with STJ height - leaflet length <0 mm (leaflet-STJ mismatch). Leaflets were at low risk (incidence 0%) if the VTC was ≥3 mm and VTSTJ was ≥3.0 mm or STJ height - leaflet length was ≥+2.0 mm. Of 28 leaflets treated using BASILICA, complete TCO was seen in 35.7% (n = 10), due to sinus sequestration (100%) with coexisting ostial obstruction (30%). Actual coronary events occurred in 7.1% (n = 2) because of leaflet prolapse, corresponding to an absolute risk reduction by BASILICA of 29% (P = 0.021).

CONCLUSIONS

Risk assessment of coronary obstruction after TAVR may improve with a multiparametric approach incorporating VTC, VTSTJ, and leaflet-STJ mismatch. BASILICA appeared to reduce actual coronary events even in leaflets with anticipated coronary obstruction.

Practical Approach to Transcatheter Aortic Valve Implantation and Bioprosthetic Valve Fracture in a Failed Bioprosthetic Surgical Valve

Bioprosthetic surgical aortic valve failure requiring reintervention is a frequent clinical problem with event rates up to 20% at 10 years after surgery. Transcatheter aortic valve-in-valve implantation (ViV-TAVI) has become a valuable treatment option for these patients, although it requires careful procedural planning. We here describe and illustrate a stepwise approach to plan and perform ViV-TAVI and discuss preprocedural computerized tomography planning, transcatheter heart valve selection, and implantation techniques. Particular attention is paid to coronary artery protection and the possible need for bioprosthetic valve fracture since patients with small surgical aortic bioprostheses are at a risk of high residual gradients after ViV-TAVI. Considering updated clinical data on long-term outcomes following ViV-TAVI, this approach may become the default treatment strategy for patients with a failing surgical aortic bioprosthesis.

Recommendations in pre-procedural imaging assessment for TAVI intervention: SIC-SIRM position paper part 2 (CT and MR angiography, standard medical reporting, future perspectives)

Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patient candidates for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. This document has been developed by a joined group of experts of the Italian Society of Cardiology and the Italian Society of Medical and Interventional Radiology and aims to produce an updated consensus statement about the pre-procedural imaging assessment in candidate patients for TAVI intervention. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac and vascular radiology. Part 2 of the document will cover CT and MR angiography, standard medical reporting, and future perspectives.

The Use of BASILICA Technique to Prevent Coronary Obstruction in a TAVI-TAVI Procedure

Transcatheter aortic valve implantation (TAVI) to manage structural bioprosthetic valve deterioration has been successful in mitigating the risk of a redo cardiac surgery. However, TAVI-in-TAVI is a complex intervention, potentially associated with feared complications such as coronary artery obstruction. Coronary obstruction risk is especially high when the previously implanted prosthesis had supra-annular leaflets and/or the distance between the prosthesis and the coronary ostia is short. The BASILICA technique (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction) was developed to prevent coronary obstruction during native or valve-in-valve interventions but has now also been considered for TAVI-in-TAVI interventions. Despite its utility, the technique requires a not so widely available toolbox. Herein, we discuss the TAVI-in-TAVI BASILICA technique and how to perform it using more widely available tools, which could spread its use.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Safeguards and pitfalls for Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction during transcatheter aortic valve replacement-the BASILICA technique

Coronary artery obstruction is a devastating complication of transcatheter aortic valve replacement (TAVR). Bioprosthetic or native Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery Obstruction (BASILICA) is a transcatheter, electrosurgical technique that was developed to prevent obstruction due to sinus effacement or sinus sequestration. BASILICA creates a midline laceration of one (solo) or both (doppio) offending aortic leaflets and has been performed in over 1,000 patients at high risk for obstruction. The procedure has been studied in the prospective BASILICA IDE Trial and data from the International BASILICA Registry of 214 patients supports efficacy and safety; procedural success was achieved in 94.4% and at thirty days 95.3% were free from culprit coronary artery obstruction, all-cause mortality was 2.8% and disabling stroke was reported in only 0.5%. In this review we discuss screening for patients at high risk for coronary artery obstruction, technical details related to performing the BASILICA procedure and how to troubleshoot a BASILICA procedure.

Balloon-Augmented Leaflet Modification With Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction and Laceration of the Anterior Mitral Leaflet to Prevent Outflow Obstruction: Benchtop Validation and First In-Man Experience

BACKGROUND

Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) and laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) reduce the risk of coronary and left ventricular outflow obstruction obstruction during transcatheter aortic valve replacement and transcatheter mitral valve replacement. Despite successful laceration, BASILICA or LAMPOON may fail to prevent obstruction caused by inadequate leaflet splay in patients having challenging anatomy such as very small valve-to-coronary distance, diffusely calcified, rigid leaflets, or undergoing transcatheter aortic valve replacement inside existing transcatheter aortic valve replacement. We describe a novel technique of balloon-augmented (BA) leaflet laceration to enhance leaflet splay.

METHODS

We measured the incremental leaflet splay from BA-BASILICA in vitro. From November 2019 to March 2021, 16 patients underwent BA-BASILICA and 4 BA-LAMPOON at 3 centers.

RESULTS

BA-BASILICA increased benchtop leaflet tip splay 17%, maximum splay angle 30%, and splay area 23%, resulting in a more rounded apex and larger effective area. Sixteen patients at risk for inadequate BASILICA leaflet splay, including 4 transcatheter aortic valve replacement inside existing transcatheter aortic valve replacement, underwent BA-BASILICA. All had successful leaflet laceration. One had coronary obstruction requiring immediate orthotopic stenting. Two underwent elective orthotopic coronary stenting through the transcatheter valve cells for leaflet prolapse without coronary ischemia. There were no deaths during the procedure or at 30 days. Four patients at risk for inadequate anterior mitral leaflet splay underwent BA-LAMPOON. All had successful target leaflet laceration without left ventricular outflow obstruction obstruction or procedural death. One died within 30 days.

CONCLUSIONS

BA leaflet laceration enhances leaflet splay in vitro and may allow transcatheter aortic valve replacement and transcatheter mitral valve replacement in patients otherwise ineligible for traditional BASILICA or LAMPOON due to challenging anatomy. Graphic Abstract: A graphic abstract is available for this article.

Conventional versus modified delivery system technique in commissural alignment from the Evolut low-risk CT substudy

OBJECTIVES

We assessed the impact of conventional delivery system (DS) insertion technique on "Hat-marker" orientation/commissural alignment in patients who underwent transcatheter aortic valve replacement (TAVR) in the Evolut Low Risk Trial CT substudy versus a modified technique.

BACKGROUND

Unlike surgical aortic valve replacement, where alignment of the surgical valve commissures with native commissures can be achieved virtually 100% of the time, commissural alignment during TAVR is not achieved consistently. This may subsequently impact the feasibility of both coronary access and reintervention after TAVR.

METHODS

"Hat-marker" orientations during deployment were characterized as outer curve (OC), center front (CF), inner curve, and center back. Severe commissure-to-CA overlap was 0-20°. "Hat-marker" orientations and CA overlap were compared to 240 patients from a single center using the modified 3-o'clock flush port DS technique.

RESULTS

In the CT substudy in which conventional DS insertion was performed (flush port at 12 o'clock); 154/249 had both analyzable CT and procedural fluoroscopy to validate "Hat-marker" to C-tab/commissural orientation. On post-TAVR CT, Evolut valve commissural orientation and coronary artery (CA) ostia were identified. Compared to conventional DS technique in the CT substudy, the modified technique had higher rates of "Hat-marker" at OC/CF orientation, improved commissural alignment and reduced severe CA overlap; (left main, 14.2 vs. 27.9%; right coronary artery, 11.7 vs. 27.3% both, 5.0 vs. 13.6%; 1 or both CA, 20.8 vs. 41.6%, all p < 0.01).

CONCLUSIONS

The modified technique improved initial "Hat-marker" orientation during Evolut deployment and resulted in better commissural alignment and reduced CA overlap.

Transcatheter Aortic Valve Replacement with a Self-Expanding Prosthesis

The self-expanding transcatheter heart valve (Medtronic Cardiovascular Corevalve and Evolut) is a supra-annular, trileafet porcine pericardial valves on a diamond lattice nickel-titanium alloy frame. The TAVR device has undergone significant improvements in design and procedural techniques to further increase safety, efficacy, and durability since they it was first released. Unique design characteristics, as well as patient and procedural factors, favor self-expanding over balloon-expandable prostheses in certain situations. The self-expanding transcatheter heart valve has proven to be an excellent option for severe aortic stenosis patients with any level of surgical risk and preliminary data suggest a comparable durability to surgical tissue valves.

Risk and Mitigation of Coronary Obstruction in Transcatheter Aortic Valve Replacement

Acute coronary artery occlusion is a rare but devastating complication of transcatheter aortic valve replacement. Coronary obstruction is angiographic evidence of a new-partial or complete-obstruction of a coronary artery. Key factors identifying patients at risk are aortic root anatomy, type of aortic valve, and type of transcatheter heart valve. Techniques to prevent coronary obstruction include intentional leaflet laceration. If acute coronary obstruction does occur, bailout stenting can be challenging and conversion to emergent open heart surgery may be required, both of which are associated with high morbidity and mortality.

5 Year Outcomes of Patients With Aortic Structural Valve Deterioration Treated With Transcatheter Valve in Valve - A Single Center Prospective Registry

The Valve-in-Valve (ViV) technique is an established alternative for the treatment of structural bioprosthetic valve deterioration (SVD). Data describing the intermediate term follow up of patients treated with this approach is scarce. We report on our intermediate-term outcomes of patients with SVD in the Aortic position treated with ViV. Included were patients with symptomatic SVD in the aortic position valve who were treated by Valve in valve transcatheter aortic valve implantation (ViV-TAVI) during the years 2010-2019 in our center. Three main outcomes were examined during the follow up period: NYHA functional class, ViV-TAVI hemodynamic per echocardiography, and mortality. Our cohort consisted of 85 patients (mean age 78.8 ± 8.9 years). The indications for aortic ViV were: SVD isolated aortic stenosis in 37.6%, SVD isolated aortic regurgitation in 42.2% and combined valve pathology in 20.0%. Self-expandable and balloon-expandable devices were used in 73 (85.9%) and 12 (14.1%), respectively. Average follow up was 3.7 ± 2.4 years. 95 and 91% of patients were in NYHA functional class I/II at 1 and 5 year follow up respectively. At one year, the mean trans-aortic valve pressure was 15 ± 9 mmHg and rates of ≥ moderate aortic regurgitation were 3.7%. Mortality at one year was 8.6% (95% CI 2.3–14.4) and 31% (95% CI 16.5–42.5) at 5 years. ViV in the aortic position offers an effective and durable treatment option for patient with SVD, with low rates of all-cause mortality, excellent hemodynamic and improved functional capacity at intermediate follow up.

Long-Term Stability and Biocompatibility of Pericardial Bioprosthetic Heart Valves

The use of bioprostheses for heart valve therapy has gradually evolved over several decades and both surgical and transcatheter devices are now highly successful. The rapid expansion of the transcatheter concept has clearly placed a significant onus on the need for improved production methods, particularly the pre-treatment of bovine pericardium. Two of the difficulties associated with the biocompatibility of bioprosthetic valves are the possibilities of immune responses and calcification, which have led to either catastrophic failure or slow dystrophic changes. These have been addressed by evolutionary trends in cross-linking and decellularization techniques and, over the last two decades, the improvements have resulted in somewhat greater durability. However, as the need to consider the use of bioprosthetic valves in younger patients has become an important clinical and sociological issue, the requirement for even greater longevity and safety is now paramount. This is especially true with respect to potential therapies for young people who are afflicted by rheumatic heart disease, mostly in low- to middle-income countries, for whom no clinically acceptable and cost-effective treatments currently exist. To extend longevity to this new level, it has been necessary to evaluate the mechanisms of pericardium biocompatibility, with special emphasis on the interplay between cross-linking, decellularization and anti-immunogenicity processes. These mechanisms are reviewed in this paper. On the basis of a better understanding of these mechanisms, a few alternative treatment protocols have been developed in the last few years. The most promising protocol here is based on a carefully designed combination of phases of tissue-protective decellularization with a finely-titrated cross-linking sequence. Such refined protocols offer considerable potential in the progress toward superior longevity of pericardial heart valves and introduce a scientific dimension beyond the largely disappointing 'anti-calcification' treatments of past decades.