The Prophylactic Chimney Snorkel Technique for the Prevention of Acute Coronary Occlusion in High Risk for Coronary Obstruction Transcatheter Aortic Valve Replacement/Implantation Cases

Intracoronary Pacing during "Chimney Technique" in Transcatheter Aortic Valve-in-Valve Implantation: An Alternative Temporary Rapid Ventricular Stimulation?

Temporary rapid ventricular pacing (TRVP) is required during transcatheter aortic valve implantation (TAVI) in order to reduce cardiac output and to facilitate balloon aortic valvuloplasty, prosthesis deployment, and post-deployment balloon dilation. The two most frequently used TRVP techniques are right endocardial (RE)-TRVP and retrograde left endocardial temporary rapid ventricular pacing (RLE)-TRVP. The first one could be responsible for cardiac tamponade, one of the most serious procedural complications during TAVI, while the second one could often be unsuccessful. Intracoronary (IC)-TRVP through a coronary guidewire has been described as a safe and efficient procedure that could avoid such complications. We describe two clinical cases in which IC-TRVP has been effectively used during valve-in-valve TAVI with coronary protection via the "chimney technique", after unsuccessful RLE-TRVP.

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.

Post-procedural structural heart CT imaging: TAVR, TMVR, and other interventions

Transcatheter valve replacement has experienced substantial growth in the past decade and this technique can now be used for any of the four heart valves. Transcatheter aortic valve replacement (TAVR) has overtaken surgical aortic valve replacement. Transcatheter mitral valve replacement (TMVR) is often performed in pre-existing valves or after prior valve repair, although numerous devices are undergoing trials for replacement of native valves. Transcatheter tricuspid valve replacement (TTVR) is similarly under active development. Lastly, transcatheter pulmonic valve replacement (TPVR) is most often used for revision treatment of congenital heart disease. Given the growth of these techniques, radiologists are increasingly called upon to interpret post-procedural imaging for these patients, particularly with CT. These cases will often arise unexpectedly and require detailed knowledge of potential post-procedural appearances. We review both normal and abnormal post-procedural findings on CT. Certain complications-device migration or embolization, paravalvular leak, or leaflet thrombosis-can occur after replacement of any valve. Other complications are specific to each type of valve, including coronary artery occlusion after TAVR, coronary artery compression after TPVR, or left ventricular outflow tract obstruction after TMVR. Finally, we review access-related complications, which are of particular concern due to the requirement of large-bore catheters for these procedures.

Coronary Obstruction during Valve-in-Valve Transcatheter Aortic Valve Replacement: Pre-Procedural Risk Evaluation, Intra-Procedural Monitoring, and Follow-Up

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) is emerging as an effective treatment for patients with symptomatically failing bioprosthetic valves and a high prohibitive surgical risk; a longer life expectancy has led to a higher demand for these valve reinterventions due to the increased possibilities of outliving the bioprosthetic valve's durability. Coronary obstruction is the most feared complication of valve-in-valve (ViV) TAVR; it is a rare but life-threatening complication and occurs most frequently at the left coronary artery ostium. Accurate pre-procedural planning, mainly based on cardiac computed tomography, is crucial to determining the feasibility of a ViV TAVR and to assessing the anticipated risk of a coronary obstruction and the eventual need for coronary protection measures. Intraprocedurally, the aortic root and a selective coronary angiography are useful for evaluating the anatomic relationship between the aortic valve and coronary ostia; transesophageal echocardiographic real-time monitoring of the coronary flow with a color Doppler and pulsed-wave Doppler is a valuable tool that allows for a determination of real-time coronary patency and the detection of asymptomatic coronary obstructions. Because of the risk of developing a delayed coronary obstruction, the close postprocedural monitoring of patients at a high risk of developing coronary obstructions is advisable. CT simulations of ViV TAVR, 3D printing models, and fusion imaging represent the future directions that may help provide a personalized lifetime strategy and tailored approach for each patient, potentially minimizing complications and improving outcomes.

Novel technique for high-risk coronary protection during implantation of transcatheter aortic valve implants

Transcatheter aortic valve replacement (TAVR) has become increasingly common as the indications expanded to include valve-in-valve (ViV) applications and a wider patient population with lower surgical risk. Intra-operative coronary arterial occlusion remains a significant source of morbidity, particularly in ViV applications or cases with high-risk anatomy. We present a novel technique for coronary artery protection utilizing a guide extension catheter to secure coronary access during valve deployment and a ViV case demonstration in a patient with prior surgical aortic valve replacement.

Evolving computed tomography angiography for aortic valve replacement: Optimizing transcatheter and surgical therapies

Transcatheter aortic valve replacement (TAVR) has transformed the treatment of aortic stenosis and pre-procedure planning relies heavily on advanced imaging. Multidetector computed tomography angiography, the "TAVR CT," facilitates essential planning steps of measuring the aortic root for valve sizing and feasibility and assessment of potential access vessels, making it the guideline gold standard in preprocedural TAVR work up. This Impact of Advanced Imaging Techniques on Cardiac Surgery article will examine the development of TAVR CT, illustrate the current impact and utility, and highlight potential areas of future growth. Clinicians who keep informed of these changes and can become proficient with TAVR CT analyses will offer patients the most optimal results and fuel future therapeutic growth.

Transcatheter Aortic Valve Replacement in Patients at High Risk of Coronary Obstruction

Background

Coronary obstruction following transcatheter aortic valve replacement (TAVR) is a life-threatening complication. For patients at elevated risk, it is not known how valve choice is influenced by clinical and anatomic factors and how outcomes differ between valve platforms. For patients at high risk of coronary obstruction, we sought to describe the anatomical and clinical characteristics of patients treated with both balloon-expandable (BE) and self-expanding (SE) valves.

Methods

This was a multicenter international registry of patients undergoing TAVR who are considered to be at high risk of coronary obstruction and receiving pre-emptive coronary protection.

Results

A total of 236 patients were included. Patients receiving SE valves were more likely to undergo valve-in-valve procedures and also had smaller sinuses of Valsalva and valve-to-coronary distance. Three-year cardiac mortality was 21.6% with SE vs 3.7% with BE valves. This was primarily driven by increased rates of definite or probable coronary occlusion, which occurred in 12.1% of patients with SE valves vs 2.1% in patients with BE valves.

Conclusions

In patients undergoing TAVR with coronary protection, those treated with SE valves had increased rates of clinical and anatomic features that increase the risk of coronary obstruction. These include an increased frequency of valve-in-valve procedures, smaller sinuses of Valsalva, and smaller valve-to-coronary distances. These patients were observed to have increased cardiac mortality compared with patients treated with BE valves, but this is likely due to their higher risk clinical and anatomic phenotypes rather than as a function of the valve type itself.

Transcatether Aortic Valve Implantation to Treat Degenerated Surgical Bioprosthesis: Focus on the Specific Procedural Challenges

Actually transcatheter aortic valve implantation within failed surgically bioprosthetic valves (VIV-TAVI) is an established procedure in patients at high risk for repeat surgical aortic valve intervention. Although less invasive than surgical reintervention, VIV-TAVI procedure offers potential challenges, such as higher rates of prosthesis-patient mismatch and coronary obstruction. Thus, optimal procedural planning plays an important role to minimize the risk of procedure complications. In this review, we describe the key points of a VIV-TAVI procedure to optimize outcomes and reduce the risk of procedure complications.

Acute Ostial Right Coronary Artery Occlusion During Valve Deployment of Transcatheter Aortic Valve Replacement Leading to Acute Right Ventricular Failure: A Perfect Storm and Successful Navigation

Acute coronary obstruction is a relatively rare complication of transcatheter aortic valve replacement (TAVR). Left coronary ostial obstruction is much more common compared to right coronary occlusion due to its relatively lower ostial height from the aortic annulus. We present a case of acute ostial right coronary occlusion immediately upon deployment of a 29-mm Sapien 3 transcatheter aortic valve. The acute right coronary ostial occlusion manifested with ventricular fibrillation, acute right ventricular failure, and right-sided cardiogenic shock. The patient, after undergoing an initial unsuccessful attempt at percutaneous revascularization, was placed on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). This was later transitioned to percutaneous right atrial to pulmonary artery right ventricular support, which led to subsequent recovery.

Overcoming the transcatheter aortic valve replacement Achilles heel: coronary re-access

Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) for the treatment of symptomatic severe aortic stenosis (AS). Coronary artery disease (CAD) is common in patients with severe AS. As the indications for TAVR extend to lower risk patients with longer life expectancy and as CAD is a progressive condition, coronary angiography will become increasingly common in patients who have had a previous TAVR. Coronary artery re-access after TAVR may be challenging but is possible in most cases. Commissural alignment of the prosthesis with the native coronary ostia plays an important role in successful coronary re-access. Coronary artery obstruction is a potentially devastating complication of TAVR, particularly in valve-in-valve procedures. In the present keynote lecture, we review techniques used to mitigate the risk of coronary obstruction, as well as catheter selection and strategies for selective coronary artery engagement for specific transcatheter aortic valve (TAV) bioprostheses.

Use of Patient-Specific 3-Dimensional Printed Models for Planning a Valve-in-Valve Transcatheter Aortic Valve Replacement and Educating Health Personnel, Patients, and Families

Background: Aortic stenosis is a common disease of the elderly. Valve replacement with open surgery is the preferred therapy for many patients with low surgical risk. Bioprosthetic valve failure occurs in up to 66% of patients and has a worse prognosis when the mechanism of failure is stenosis compared to regurgitation.

Case Report: An 80-year-old female with a medical history of surgical aortic valve replacement, diabetes, chronic back pain, coronary artery disease, and hypertension was referred to the interventional cardiology clinic for heart failure symptoms. A bioprosthetic valve placement that was small for the patient's size (effective orifice area/body surface area 0.75 cm²/m²) resulted in symptomatic improvement that lasted for 7 years. The patient underwent an aortic valve-in-valve transcatheter valve replacement with excellent outcomes. Preoperative planning involved a patient-specific 3-dimensional printed patient model.

Conclusion: In patients at high surgical risk, transcatheter aortic valve replacement is a fundamental pillar of treatment. However, valve-in-valve procedures have specific anatomic challenges, such as the risk of coronary artery obstruction and the limitation of valve expansion inside a rigid bioprosthetic valve frame. In those difficult cases, interventional cardiologists must make precise decisions regarding the approach. Three-dimensional models can be printed with the patient's specific measurements. This approach represents truly personalized medicine and can serve as a tool for procedural planning, education of the health personnel involved in the case, and patient and family engagement.

Transcatheter aortic valve replacement: potential use in lower-risk aortic stenosis

INTRODUCTION

The widespread use of transcatheter aortic valve implantation (TAVI) is expanding to low-risk patients. Nevertheless, a low clinical risk does not always correspond to a low procedural risk for the percutaneous approach.

AREAS COVERED

The initial trials on TAVI in low-risk populations had encouraging results, showing non-inferiority in comparison to surgical aortic valve replacement (SAVR). However, the low-risk definition is based on risk score calculators developed for the surgical setting and not including other specific features that are more relevant to TAVI and can affect procedural outcomes. For example, the presence of bicuspid aortic valves, high calcific burden, low coronary height or conduction disturbances is all potentially associated with suboptimal results or even procedural complications. In addition, the lack of longer follow-up prevents us to draw conclusions about long-term outcomes, including data about valve durability and coronary re-access.

EXPERT OPINION

Although current evidence suggest similar results for TAVI and SAVR in low-risk populations, there are some technical and procedural limitations that still need to be addressed in order to close the gap between TAVI and surgery. Optimal, lasting results with a low rate of procedural complications are highly expected in low-risk, otherwise healthy subjects, with potential for longevity.

Guide Extension-Assisted Stent Implantation at Ostial Right Coronary Artery Creating Stent Tunnel During Transcatheter Aortic Valve Replacement

Coronary artery occlusion is an uncommon but life-threatening complication of transcatheter aortic valve replacement (TAVR). Both low coronary artery height and externally mounted stented bioprosthesis present an increased risk for coronary artery occlusion, and various prevention strategies have been recommended. We present an 86-year-old woman with failed surgical bioprosthesis, concomitant obstructive ostial right coronary artery (RCA) lesion, and low coronary ostial heights who underwent simultaneous TAVR and percutaneous coronary intervention of ostial RCA. Due to suprannular valve expansion after post-dilation, the RCA ostium was compromised, and a novel stent tunnel was created under the native leaflets towards the left coronary sinus to maintain RCA perfusion.

How to Avoid Coronary Occlusion During TAVR Valve-in-Valve Procedures

Transcatheter aortic valve-in-valve replacement has been recently reported as a less-invasive alternative to re-do surgery in patients with bioprosthetic valve failure. Although procedural success is achieved in the great majority of patients, this therapy is associated with several potential complications, and coronary occlusion is one of the most feared. This is a rare event, but it is associated with an extremely poor prognosis. In this review, the mechanisms, the identification of patients at high risk, the primary prevention strategies, and treatment of coronary occlusion will be discussed.

[Management of non-rhythmic complications of TAVI procedures]

Transcatheter aortic valve (TAVI) is the treatment of choice in patients with severe symptomatic aortic stenosis at high surgical risk. Recent data have also shown favorable results in patients considered to have an intermediate operative risk, which broadens the application of this new technology. Despite its success, the TAVI procedure has been associated with life-threatening complications. Advances in preoperative screening and patient selection have reduced the incidence of these complications. When these complications occur, early recognition and rapid management are essential. The purpose of this review is to describe non-rhythmic mechanical complications attributable to TAVI procedures with their predictive factors, how to prevent and manage them.