Transcatheter Aortic Valve-in-Valve Procedure in Patients with Bioprosthetic Structural Valve Deterioration

Aortic Valve-in-Valve Procedures: Challenges and Future Directions

Aortic valve-in-valve (ViV) procedures are increasingly performed for the treatment of surgical bioprosthetic valve failure in patients at intermediate to high surgical risk. Although ViV procedures offer indisputable benefits in terms of procedural time, in-hospital length of stay, and avoidance of surgical complications, they also present unique challenges. Growing awareness of the technical difficulties and potential threats associated with ViV procedures mandates careful preprocedural planning. This review article offers an overview of the current state-of-the-art ViV procedures, with focus on patient and device selection, procedural planning, potential complications, and long-term outcomes. Finally, it discusses current research efforts and future directions aimed at improving ViV procedural success and patient outcomes.

Comparison of modes of failure and clinical outcomes between explanted porcine and bovine pericardial bioprosthetic valves

OBJECTIVE

To compare pathological and hemodynamic modes of failure and operative outcomes between explanted porcine and bovine pericardial bioprosthetic valves.

METHODS

Patients who underwent explantation of their bioprosthetic valves at Toronto General Hospital from 2007 to 2019 were identified. Retrospective chart review was conducted to attain demographic information, operative outcomes, and echocardiography and pathology reports.

RESULTS

A total of 278 patients underwent explantation of their porcine (n=183) or bovine pericardial (n=95) valves. A greater proportion of the porcine group had severe regurgitation, compared to the bovine group (45.3% vs. 19.8%, p<.001). Porcine valves had higher rates of cusp flail (19.4% vs. 3.3%, p<.001). The rates of moderate or worse stenosis were higher among bovine pericardial valves (37.9% vs. 15.8%, p<.001). On pathologic examination, the porcine valves exhibited more cusp tears (67.6% vs. 50.5%, p=.006), while higher incidences of calcification were found in the bovine group (p<.001). Rate of stroke was higher during the explantation procedure of the bovine valves (5.3% vs. 0.5%, p=.040).

CONCLUSIONS

The primary mode of failure was regurgitation in porcine valves due to cusp tears and stenosis in bovine valves due to calcification. Establishing a clear understanding of failure modes based on valve material may improve design and guide valve selection at the time of surgery.

Valve-in-valve transcatheter aortic valve implantation versus repeat surgical aortic valve replacement in patients with a failed aortic bioprosthesis

BACKGROUND

Limited data are available regarding clinical outcomes of valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) following the United States Food and Drug Administration approval of ViV TAVI in 2015.

AIMS

The aim of this study was to evaluate in-hospital, 30-day, and 6-month outcomes of ViV TAVI versus repeat surgical aortic valve replacement (SAVR) in patients with a failed aortic bioprosthetic valve.

METHODS

This retrospective cohort study identified patients who underwent ViV TAVI or repeat SAVR utilising the Nationwide Readmission Database from 2016 to 2018. Primary outcomes were all-cause readmission (at 30 days and 6 months) and in-hospital death. Secondary outcomes were in-hospital stroke, pacemaker implantation, 30-day/6-month major adverse cardiac events (MACE), and mortality during readmission. Propensity score-matching (inverse probability of treatment weighting) analyses were implemented.

RESULTS

Out of 6,769 procedures performed, 3,724 (55%) patients underwent ViV TAVI, and 3,045 (45%) underwent repeat SAVR. ViV TAVI was associated with lower in-hospital all-cause mortality (odds ratio [OR] 0.42, 95% confidence interval [CI]: 0.20-0.90, p=0.026) and a higher rate of 30-day (hazard ratio [HR] 1.46, 95% CI: 1.13-1.90, p=0.004) and 6-month all-cause readmission (HR 1.54, 95% CI: 1.14-2.10, p=0.006) compared with repeat SAVR. All secondary outcomes were comparable between the two groups.

CONCLUSIONS

ViV TAVI was associated with lower in-hospital mortality but higher 30-day and 6-month all-cause readmission. However, there was no difference in risk of in-hospital stroke, post-procedure pacemaker implantation, MACE, and mortality during 30-day and 6-month readmission compared with repeat SAVR, suggesting that ViV TAVI can be performed safely in carefully selected patients.

The role of echocardiography in the management of structural valve degeneration of transcatheter valves

Transcatheter valve implantation in patients with aortic stenosis has evolved as an acceptable alternative to surgical aortic valve replacement in a subset of patients at excessively high risk from surgery. The structural valve degeneration (SVD) is a known phenomenon in catheter-based valves too, which was hitherto seen with surgical bioprosthetic valves. Echocardiography plays a pivotal role not only in early detection but also in the management of SVD of Transcatheter valves. The goal of this report is to agglomerate our experience of an unusual case of SVD of a catheter-based valve implanted inside the bioprosthetic aortic and mitral valve apparatus and its management with aortic and mitral valve replacement with mechanical valve prosthesis.

Hemodynamic outcomes after valve-in-valve transcatheter aortic valve replacement: a single-center experience

Background

Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) has emerged as a safe, effective alternative to redo aortic valve surgery in high-risk patients with degenerated surgical bioprosthetic valves. However, ViV-TAVR has been associated high postprocedural valvular gradients, compared with TAVR for native-valve aortic stenosis.

Methods

We performed a retrospective study of all patients who underwent ViV-TAVR for a degenerated aortic valve bioprosthesis between January 1, 2013 and March 31, 2019 at our center. The primary outcome was postprocedural mean aortic valve gradient. Outcomes were compared across surgical valve type (stented versus stentless), surgical valve internal diameter (≤19 versus >19 mm), and transcatheter aortic valve type (self-expanding vs. balloon-expandable).

Results

Overall, 89 patients underwent ViV-TAVR. Mean age was 69.0±12.6 years, 61% were male, and median Society of Thoracic Surgeons Predicted Risk of Mortality score was 5.4 [interquartile range, 3.2-8.5]. Bioprosthesis mode of failure was stenotic (58% of patients), regurgitant (24%), or mixed (18%). The surgical valve was stented in 75% of patients and stentless in 25%. The surgical valve's internal diameter was ≤19 mm in 45% of cases. A balloon-expandable transcatheter valve was used in 53% of procedures. Baseline aortic valve area and mean gradients were 0.87±0.31 cm² and 36±18 mmHg, respectively. These improved after ViV-TAVR to 1.38±0.55 cm² and 18±11 mmHg at a median outpatient follow-up of 331 [67-394] days. Higher postprocedural mean gradients were associated with surgical valves having an internal diameter ≤19 mm (24±13 versus 16±8, P=0.002) and with stented surgical valves (22±11 versus 12±6, P<0.001).

Conclusions

ViV-TAVR is an effective option for treating degenerated surgical aortic bioprostheses, with acceptable hemodynamic outcomes. Small surgical valves and stented surgical valves are associated with higher postprocedural gradients.

Valve-in-Valve Transcatheter Aortic Valve Replacement, with Present-Day Innovations and Up-to-Date Techniques

Approximately 51,000 to 65,000 surgical aortic valve replacement (SAVR) cases are performed in the United States anually. Bioprosthetic degeneration commonly occurs within 10 to 15 years, and nearly 800 redo SAVR cases occur each year. Valve-in-valve transcatheter aortic valve replacement (ViV TAVR) has emerged as a safe and effective alternative, as the Food and Drug Administration approved ViV TAVR with self-expanding transcatheter heart valve in 2015 and balloon-expandable valve in 2017 for failed surgical valves cases at high risk of reoperation. We review ViV TAVR, with specific attention to procedural planning, technical challenges, associated complications, and long-term follow-up.

Incidence, Predictors, and Implications of Permanent Pacemaker Requirement After Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is a safe and feasible alternative to surgery in patients with symptomatic severe aortic stenosis regardless of the surgical risk. Conduction abnormalities requiring permanent pacemaker (PPM) implantation remain a common finding after TAVR due to the close proximity of the atrioventricular conduction system to the aortic root. High-grade atrioventricular block and new onset left bundle branch block (LBBB) are the most commonly reported conduction abnormalities after TAVR. The overall rate of PPM implantation after TAVR varies and is related to pre-procedural and intraprocedural factors. The available literature regarding the impact of conduction abnormalities and PPM requirement on morbidity and mortality is still conflicting. Pre-procedural conduction abnormalities such as right bundle branch block and LBBB have been linked with increased PPM implantation and mortality after TAVR. When screening patients for TAVR, heart teams should be aware of various anatomical and pathophysiological conditions that make patients more susceptible to increased risk of conduction abnormalities and PPM requirement after the procedure. This is particularly important as TAVR has been recently approved for patients with low surgical risk. The purpose of this review is to discuss the incidence, predictors, impact, and management of the various conduction abnormalities requiring PPM implantation in patients undergoing TAVR.

Bioprosthetic aortic valve diameter and thickness are directly related to leaflet fluttering: Results from a combined experimental and computational modeling study

OBJECTIVE

Bioprosthetic heart valves (BHVs) are commonly used in surgical and percutaneous valve replacement. The durability of percutaneous valve replacement is unknown, but surgical valves have been shown to require reintervention after 10 to 15 years. Further, smaller-diameter surgical BHVs generally experience higher rates of prosthesis-patient mismatch, which leads to higher rates of failure. Bioprosthetic aortic valves can flutter in systole, and fluttering is associated with fatigue and failure in flexible structures. The determinants of flutter in BHVs have not been well characterized, despite their potential to influence durability.

METHODS

We use an experimental pulse duplicator and a computational fluid-structure interaction model of this system to study the role of device geometry on BHV dynamics. The experimental system mimics physiological conditions, and the computational model enables precise control of leaflet biomechanics and flow conditions to isolate the effects of variations in BHV geometry on leaflet dynamics.

RESULTS

Both experimental and computational models demonstrate that smaller-diameter BHVs yield markedly higher leaflet fluttering frequencies across a range of conditions. The computational model also predicts that fluttering frequency is directly related to leaflet thickness. A scaling model is introduced that rationalizes these findings.

CONCLUSIONS

We systematically characterize the influence of BHV diameter and leaflet thickness on fluttering dynamics. Although this study does not determine how flutter influences device durability, increased flutter in smaller-diameter BHVs may explain how prosthesis-patient mismatch could induce BHV leaflet fatigue and failure. Ultimately, understanding the effects of device geometry on leaflet kinematics may lead to more durable valve replacements.

Sutureless Valve in Repeated Aortic Valve Replacement: Results from an International Prospective Registry

OBJECTIVE

To report early and midterm results registry of patients undergoing repeated aortic valve replacement (RAVR) with sutureless prostheses from an international prospective registry (SURE-AVR).

METHODS

Between March 2011 and June 2019, 69 patients underwent RAVR with self-expandable sutureless aortic bioprostheses at 22 international cardiac centers.

RESULTS

Overall mortality was 2.9% with a predicted logistic EuroSCORE II of 10.7%. Indications for RAVR were structural valve dysfunction (84.1%) and infective prosthetic endocarditis (15.9%) and were performed in patients with previously implanted bioprostheses (79.7%), mechanical valves (15.9%), and transcatheter valves (4.3%). Minimally invasive approach was performed in 15.9% of patients. Rate of stroke was 1.4% and rate of early valve-related reintervention was 1.4%. Overall survival rate at 1 and 5 years was 97% and 91%, respectively. No major paravalvular leak occurred. Rate of pacemaker implantation was 5.8% and 0.9% per patient-year early and at follow-up, respectively. The mean transvalvular gradient at 1-year and 5-year follow-up was 10.5 mm Hg and 11.5 mm Hg with a median effective orifice area of 1.8 cm²and 1.8 cm², respectively.

CONCLUSIONS

RAVR with sutureless valves is a safe and effective approach and provides excellent clinical and hemodynamic results up to 5 years.

Noncalcific Mechanisms of Bioprosthetic Structural Valve Degeneration

Bioprosthetic heart valves (BHVs) largely circumvent the need for long‐term anticoagulation compared with mechanical valves but are increasingly susceptible to deterioration and reduced durability with reoperation rates of ≈10% and 30% at 10 and 15 years, respectively. Structural valve degeneration is a common, unpreventable, and untreatable consequence of BHV implantation and is frequently characterized by leaflet calcification. However, 25% of BHV reoperations attributed to structural valve degeneration occur with minimal leaflet mineralization. This review discusses the noncalcific mechanisms of BHV structural valve degeneration, highlighting the putative roles and pathophysiological relationships between protein infiltration, glycation, oxidative and mechanical stress, and inflammation and the structural consequences for surgical and transcatheter BHVs.

Transcatheter Aortic Valve Replacement Programs: Clinical Outcomes and Developments

Transcatheter aortic valve replacement is a relatively recent revolutionary treatment that has now become a standard procedure for treating severe aortic stenosis. In this article, the authors review the clinical history of transcatheter aortic valve replacement, summarize the major clinical trials, and describe the evolution of the technique over time. In doing so, the authors hope to provide a clear and concise review of the history and clinical evidence behind transcatheter aortic valve replacement.

Percutaneous valve-in-valve procedure and simultaneous paravalvular leak closure

Concern for early degeneration limits the use of bioprosthetic heart valves. A 77-year-old man who underwent surgical aortic valve replacement at age 70 for severe aortic stenosis (AoS) presented with premature bioprosthesis degeneration and AoS recurrence. Transthoracic echocardiography demonstrated severe AoS and aortic regurgitation, a 30% ejection fraction, and pulmonary hypertension. Transesophageal echocardiography revealed that the aortic regurgitation was due to a 5-mm paravalvular leak (PVL). A high EuroScoreII excluded surgical treatment. Simultaneous transcatheter aortic valve replacement and PVL closure with an Occlutech PLD Square 5 Twist PVL closure device were performed with good results and improved clinical status.

Double Valve-in-Valve Transcatheter Valve Replacements for Failed Surgical Bioprosthetic Aortic and Tricuspid Valves

Transcatheter technology has revolutionized the treatment of valvular disease in the field of cardiology and cardiac surgery. We present an interesting case of a patient with prior double valve replacements, which had degenerated after a decade, with symptoms of decompensated heart failure. The patient was successfully treated with double valve-in-valve transcatheter aortic and tricuspid valve replacement.

Tissue versus mechanical aortic valve replacement in younger patients: A multicenter analysis

OBJECTIVE

The goal of this study was to examine the long-term survival of patients between the ages of 50 and 65 years who underwent tissue versus mechanical aortic valve replacement (AVR) in a multicenter cohort.

METHODS

A multicenter, retrospective analysis of all AVR patients (n = 9388) from 1991 to 2015 among 7 medical centers reporting to a prospectively maintained clinical registry was conducted. Inclusion criteria were: patients aged 50 to 65 years who underwent isolated AVR. Baseline comorbidities were balanced using inverse probability weighting for a study cohort of 1449 AVRs: 840 tissue and 609 mechanical. The primary end point of the analysis was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation.

RESULTS

During the study period, there was a significant shift from mechanical to tissue valves (P < .001). There was no significant difference in major in-hospital morbidity, mortality, or length of hospitalization. Also, there was no significant difference in adjusted 15-year survival between mechanical versus tissue valves (hazard ratio, 0.87; 95% confidence interval [CI], 0.67-1.13; P = .29), although tissue valves were associated with a higher risk of reoperation with a cumulative incidence of 19.1% (95% CI, 14.4%-24.3%) versus 3.0% (95% CI, 1.7%-4.9%) for mechanical valves. The reoperative 30-day mortality rate was 2.4% (n = 2) for the series.

CONCLUSIONS

Among patients 50 to 65 years old who underwent AVR, there was no difference in adjusted long-term survival according to prosthesis type, but tissue valves were associated with a higher risk of reoperation.

Description of the aortic root anatomy in relation to transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) has emerged as a less invasive treatment than surgical aortic valve replacement in patients with aortic stenosis. Understanding the anatomy of aortic valve complex may help in optimal positioning of prosthetic valve and circumvent complications that can arise during its implantation.

MATERIAL AND METHODS

The anatomy of aortic root was studied in 30 formalin-fixed cadavers. Aortic root and left ventricular cavity was opened to measure the diameter at the base of aortic root and sinotubular junction (STJ); distance of coronary ostia from base of aortic root and STJ; height and width of aortic valve leaflets; length and thickness of membranous septum (MS).

RESULTS

The diameter of aorta at the base of aortic root and STJ was 22.4±2.1 mm and 21.8±2.4 mm, respectively. The height of aortic leaflets was smaller than the width. The right and left coronary ostia were 10.7±1.9 mm and 10.5±1.9 mm above the base of aortic root. Membranous septum was 4.7±1.23 mm (range 2.9-6.1 mm) long and formed part of the wall of aortic root in 40% (12/30) cases.

CONCLUSIONS

Low lying coronary ostia speculate the use of a small prosthesis size to avoid or reduce the degree of coronary compression. Length of MS may help in deciding the extent of devise penetration into left ventricular outflow tract to avoid conduction block. Membranous septum forming wall of aortic root increases the risk of aortic root rupture and iatrogenic membranous defect during TAVI.