Transcatheter Aortic Valve Implantation for Failing Surgical Aortic Bioprosthetic Valve

Transcatheter aortic valve implantation for structural valve deterioration of homograft surgical aortic valve using SAPIEN3 Ultra RESILIA: a case report

Background

There are a few case reports regarding transcatheter aortic valve implantation (TAVI) for deteriorated surgical homograft.

Case summary

We present a case of severe structural valve deterioration (SVD) of homograft surgical aortic valve presenting severe aortic regurgitation in an 84-year-old man with decompensated heart failure. We performed TAVI in homograft valve using 23 mm SAPIEN3 Ultra RESILIA. The resulting grade of paravalvular regurgitation was trace, the post-operative effective orifice area (EOA) was 1.66 cm2 (index EOA: 1.19 cm2/m2), and device success was achieved.

Discussion

Stented bioprosthetic valves are more commonly implanted than mechanical and stentless bioprosthetic valves. In the 1980s and the early 1990s, homografts became particularly popular as alternatives to stented valves. There are several reports of TAVI for homograft SVD, but the paravalvular leakage grade is worse than that of redo-surgical aortic valve replacement, although the mortality rate is lower. However, the valves used in these reports were from older valves such as SAPIEN XT or SAPIEN3. There are no reports using SAPIEN3 Ultra RESILIA with a significant reduction in paravalvular leak due to an external textured polyethylene terephthalate skirt extending 40% higher above the valve inflow than the classical SAPIEN3, which is now available. Transcatheter aortic valve implantation using SAPIEN3 Ultra RESILIA showed good therapeutic efficacy.

Hemodynamic follow-up after valve-in-valve TAVR for failed aortic bioprosthesis

BACKGROUND

"valve-in-valve" TAVR (VIV-TAVR) is established and provides good initial clinical and hemodynamic outcomes. Lacking long-term durability data baffle the expand to lower risk patients. For those purposes, the present study adds a hemodynamic 3-years follow-up.

METHODS

A total of 77 patients underwent VIV-TAVR for failing aortic bioprosthesis during a 7-years period. Predominant mode of failure was stenosis in 87.0%. Patients had a mean age of 79.4 ± 5.8 years and a logistic EuroSCORE of 30.8 ± 15.7%. The Society of Thoracic Surgeons-PROM averaged 5.79 ± 2.63%. Clinical results and hemodynamic outcomes are reported for 30-days, 1-, 2-, and 3-years. Completeness of follow-up was 100% with 44 patients at risk after 3-years. Follow-up ranged up to 7.1 years.

RESULTS

Majority of the surgical valves were stented (94.8%) with a mean labeled size of 23.1 ± 2.3 mm and true-ID of 20.4 ± 2.6 mm. A true-ID ≤21 mm had 58.4% of the patients. Self-expanding valves were implanted in 68.8% (mean labeled size 24.1 ± 1.8 mm) and balloon-expanded in 31.2% (mean size 24.1 ± 1.8 mm). No patient died intraoperatively. Hospital mortality was 1.3% and three-years survival 57.1%. All patients experienced an initial significant dPmean-reduction to 16.8 ± 7.1 mmHg. After 3-years mean dPmean raised to 26.0 ± 12.2 mmHg. This observation was independent from true-ID or type of transcatheter aortic valve replacement (TAVR)-prosthesis. Patients with a true-ID ≤21 mm had a higher initial (18.3 ± 5.3 vs. 14.9 ± 7.1 mmHg; p = .005) and dPmean after 1-year (29.2 ± 8.2 vs. 13.0 ± 6.7 mmHg; p = .004). There were no significant differences in survival.

CONCLUSIONS

VIV-TAVR is safe and effective in the early period. In surgical valves with a true-ID ≤21 mm inferior hemodynamic and survival outcomes must be expected. Nonetheless, also patients with larger true-IDs showed steadily increasing transvalvular gradients. This raises concern about durability.

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.

Transcatheter valve-in-valve implantation for degenerated stentless aortic bioroots

Background

Open surgical repair of a failed valve-sparing aortic root replacement (VSARR) or stentless bioroot aortic root replacement (bio-ARR) entails significant operative risks. Whether valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) is feasible in patients with a previous VSARR or stentless bio-ARR remains unclear, given lingering concerns about the ill-defined aortic annulus in these patients and the potential for coronary obstruction. We present our experience with patients who had a previous VSARR or stentless bio-ARR and underwent ViV-TAVR to repair a degenerated aortic valve with combined valvular disease, aortic insufficiency and aortic stenosis.

Methods

In this retrospective data review, we identified and analyzed consecutive patients with a previous VSARR or stentless bio-ARR who underwent ViV-TAVR between December 1, 2014 and August 31, 2019.

Results

ViV-TAVR was performed in twelve high-risk patients with previous VSARR or bio-ARR during the study period. Of these, seven received Medtronic Freestyle porcine stentless bioprosthetic aortic roots, three received homograft aortic roots, one underwent a Ross procedure and one underwent VSARR. ViV-TAVR restored satisfactory valve function in all patients, and technical success was 100%. No patient had more than mild regurgitation after implantation. No thirty-day mortality was seen. One patient had major bleeding after transapical access, one patient had a transient ischemic stroke, and one patient needed permanent pacemaker implantation. At a median last follow-up of 21.5 months (interquartile range, 9.0-69.0 months), all patients remained alive and had satisfactory valve function.

Conclusions

In this study, ViV-TAVR was a clinically effective option for treating patients with a failed stentless bio-ARR or previous VSARR. Short-term and intermediate-term results after these procedures were favorable. These findings may have important implications for treating high-risk patients with structural aortic root deterioration and call for better transcatheter heart valves that are suitable for treating aortic insufficiency.

Transoesophageal echocardiography-guided 'primary' valve-in-valve technique in cardiogenic shock: a case report

Background

Transcatheter aortic valve implantation inside a previously implanted bioprosthesis is an alternative treatment for patients with degenerated surgical aortic bioprosthesis (AB) at high surgical risk. Pre-operative computed tomography (CT) scan provides essential information to the procedure planning, although in case of acute presentation it is not always feasible.

Case summary

A 32-year-old man with history of surgical treatment of aortic coarctation and Bio-Bentall procedure was transferred to our department in cardiogenic shock with a suspected diagnosis of acute myocarditis. A transthoracic echocardiogram (TTE) revealed a severely impaired biventricular function and AB degeneration causing severe stenosis. It was decided to undertake an urgent trans-apical valve-in-valve (ViV) procedure. Due to haemodynamic instability, a preoperative CT scan was not performed and transoesophageal echocardiography (TOE) was the main intraprocedural guiding imaging technique. Neither intraprocedural nor periprocedural complications occurred. Serial post-procedural TTE exams showed good functioning of the bioprosthesis and progressive improvement of left ventricular ejection fraction. Patient was discharged from the hospital 8 days after the intervention.

Discussion

A patient with cardiogenic shock due to severe degeneration of the AB was treated with urgent transapical ViV procedure. In this case, where urgent ViV technique was needed, TOE appeared to be a crucial alternative to CT scan and allowed us to perform a successful procedure.

Bioprosthetic valve fracture during valve-in-valve transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) valve-in-valve (VIV) therapy has been approved for select patients with surgically inoperable bioprosthetic valves that need replacement. Bioprosthetic valve fracturing (BVF) used in conjunction with VIV TAVR can reduce transvalvular gradients and increase the aortic valve area. Twelve patients who underwent BVF VIV TAVR at a single center were retrospectively analyzed. Measurements of hemodynamics and aortic valve area were performed at baseline, after VIV TAVR, after BVF, and at 30-day follow-up. The mean Society of Thoracic Surgeons Predicted Risk of Mortality score was 7.12 ± 3.5%, with 75% of patients deemed high risk by the heart team. Mean gradients decreased from 44 mm Hg to 15 mm Hg following VIV TAVR, and to 7 mm Hg following BVF. The mean aortic valve area increased from 0.6 cm² to 1 cm² following VIV TAVR, and to 1.3 cm² following BVF. There were no postoperative permanent pacemaker implantations or vascular complications, and at 30 days, only one patient had died. While we report intraoperative mortality, BVF with VIV TAVR can be performed to reduce transvalvular gradients and increase effective aortic valve area in high-surgical-risk patients with failed bioprosthetic valves.

Quality of life in sexagenarians after aortic biological vs mechanical valve replacement: a single-center study in China

Objective

This article aimed to study the quality of life and anxiety of sexagenarian patients who underwent aortic biological vs mechanical valve replacement in a single center in China.

Methods

The clinical data of 78 patients aged 60 to 70 years who underwent aortic prosthetic valve replacement were retrospectively analyzed in our hospital from June 2017 to February 2018. Patients were divided into two groups depending on the type of prosthetic valve they received (biological valve group vs mechanical valve group). The SF-36 was completed by all patients at discharge and at one-year follow-up, and the cardiac anxiety questionnaire (CAQ) was also completed at one-year follow-up.

Results

There was no statistically significant difference between the two groups in general clinical data or SF-36 score at discharge. However, at one-year follow-up, the SF-36 scores were significantly higher in the biological valve group than in the mechanical valve group, and the CAQ scores in fear and anxiety, avoidance and attention in the mechanical valve group were significantly higher than those in the biological valve group.

Conclusions

Based on the postoperative quality of life and anxiety scores of sexagenarian patients who underwent biological vs mechanical valve replacement in this study, a biological valve has more value than a mechanical valve for sexagenarians undergoing aortic valve replacement.

Successful implantation of self-expanding valve for a failed stentless prosthesis

Valve-in-valve transcatheter aortic valve implantation is currently used for failed bioprosthesis. The use of a transcatheter prosthesis in a regurgitant noncalcified root implanted Medtronic Freestyle prosthesis is particularly challenging. We present a successful transaxillary valve-in-valve implantation of a self-expandable transcatheter aortic valve prosthesis in a failed Freestyle bioprothesis implanted eleven years earlier. Tips and tricks are discussed.

Studying Xenograft Rejection of Bioprosthetic Heart Valves

Millions of patients with valvular heart disease have benefitted from heart valve replacement since the procedure was first introduced in the 1960s; however, there are still many patients who get early structural valve deterioration (SVD) of their bioprosthetic heart valves (BHV). BHV are porcine, bovine, or equine tissues that have been glutaraldehyde fixed to preserve the tissue and presumably make the tissue immunologically inert. These glutaraldehyde-fixed BHV with anti-calcification treatments last long periods of time in older adults but develop early SVD in younger patients. The consensus at present is that the early SVD in younger patients is due to more "wear and tear" of the valves and higher calcium turnover in younger patients. However, as younger patients likely have a more robust immune system than older adults, there is a new hypothesis that BHV xenografts may undergo xenograft rejection, and this may contribute to the early SVD seen in younger patients.At present, the technology to noninvasively study in vivo whether an implanted BHV in a human patient is undergoing rejection is not available. Thus, a small animal discordant xenotransplant model in young rodents (to match the young patient getting a pig/bovine/equine BHV) was developed to study whether the hypothesis that glutaraldehyde-fixed BHV undergo xenograft rejection had any merit. In this chapter, we describe our model and its merits and the results of our investigations. Our work provides clear evidence of xenograft rejection in glutaraldehyde-fixed tissue, and our small animal model offers an opportunity to study this process in detail.

Donkey pericardium compares favorably with commercial xenopericardia used in the manufacture of transcatheter heart valves

Transcatheter aortic valve implantation (TAVI) has gained considerable acceptance in the past decade due to its lower risks than conventional open-heart surgery. However, the deformation and delamination of the leaflets during the crimping procedure have raised questions about the durability and long-term serviceability of the pericardium tissue from which the leaflets are made. The collagen architecture, wall thickness and mechanical properties of donkey pericardium were investigated to assess its suitability as an alternative material for the manufacture of heart valves. Coupons sampled from different locations of donkey pericardium were investigated. Bovine, equine, and porcine pericardium specimens served as controls. The donkey pericardium had a similar surface morphology to that of the control pericardia except for the wavy topology on both the fibrous and serous sides. The average thickness of donkey pericardium (ca. 120 µm) was significantly lower than that from bovine (375 µm) and equine (410 µm), but slightly higher than that from porcine (99 µm) specimens. The interlaced wavy collagen bundles in the pericardium were composed of collagen fibers about 100 nm in diameter. This unique structure ensures that the donkey pericardium has a comparable ultimate tensile strength (UTS) and a much higher failure strain than the commercial pericardia used for the manufacture of heart valves. The donkey pericardium has an organized wavy collagen bundle architecture similar to that of bovine pericardium and has a satisfactory UTS and high failure strain. The thin and strong donkey pericardium might be a good candidate valve leaflet material for TAVI.

Direct Transcatheter Valve Deployment via Sternotomy for Complex Aortic Valve Reoperation

Reoperative aortic valve replacement is associated with increased morbidity. Valve-in-valve transcatheter aortic valve replacement offers a less invasive alternative to traditional reoperation. However, cases of valve failure after valve-in-valve transcatheter aortic valve replacement represent a complex surgical challenge. We present a case requiring a complex reoperative aortic valve replacement due to structural valve deterioration after multiple previous valve-in-valve transcatheter aortic valve replacements. We performed removal of 3 previous valve-in-valve transcatheter aortic valves, bioprosthetic leaflet excision, and intentional bioprosthetic fracture under direct vision for annular enlargement. This facilitated direct insertion of a new transcatheter aortic valve for expedient and successful management of recurrent aortic stenosis in a very high-risk patient. Creative use of leaflet excision, intentional bioprosthetic fracture, and insertion of a new transcatheter aortic valve under direct vision, proved efficient and successful in a high-risk patient with few surgical options.

A comparison of valve-in-valve transcatheter aortic valve replacement in failed stentless versus stented surgical bioprosthetic aortic valves

Objectives

The objectives of this study were to compare short‐ and intermediate‐term clinical outcomes, procedural complications, TAVR prosthesis hemodynamics, and paravalvular leak (PVL) in stentless and stented groups.

Background

Valve‐in‐valve (ViV) transcatheter aortic valve replacement (TAVR) is an alternative to surgical redo for bioprosthetic valve failure. There have been limited data on ViV in stentless surgical valves.

Methods

We retrospectively analyzed 40 patients who underwent ViV TAVR in prior surgical bioprosthetic valves at Wake Forest Baptist Medical Center from October 2014 to September 2017. Eighty percent (32/40) ViV TAVRs were in stentless, while 20% (8/40) were in stented bioprosthetic valves.

Results

The primary mode of bioprosthetic valve failure for ViV implantation in the stentless group was aortic insufficiency (78%, 25/32), while in the stented group was aortic stenosis (75%, 6/8). The ViV procedure success was 96.9% (31/32) in stentless group and 100% in stented group (8/8). There were no significant differences in all‐cause mortality at 30 days between stentless and stented groups (6.9%, 2/31 versus 0%, 0/8, P = 0.33) and at 1 year (0%, 0/25 versus 0%, 0/5). In the stentless group, 34.4% (11/32) required a second valve compared to the stented group of 0% (0/8). There was a significant difference in the mean aortic gradient at 30‐day follow‐up (12.33 ± 6.33 mmHg and 22.63 ± 8.45 mmHg in stentless and stented groups, P < 0.05) and at 6‐month follow‐up (9.75 ± 5.07 mmHg and 24.00 ± 11.28 mmHg, P < 0.05), respectively.

Conclusions

ViV in the stentless bioprosthetic aortic valve has excellent procedural success and intermediate‐term results. Our study shows promising data that may support the application of TAVR in stentless surgical aortic valve. However, further and larger studies need to further validate our single center's experience.

Conventional redo biological valve replacement over 20 years: Surgical benchmarks should guide patient selection for transcatheter valve-in-valve therapy

OBJECTIVES

Although primary transcatheter valve interventions have demonstrated acceptable early- and intermediate-term outcomes, data are lacking to guide patient selection for transcatheter valve-in-valve therapy. Furthermore, very few surgical benchmarks have been established for repeat conventional biological valve replacement to refine momentum for broad application of transcatheter intervention for a degenerated bioprosthesis.

METHODS

From January 1993 to July 2014, 694 patients underwent repeat biological valve replacement at our clinic. Median age at repeat operation was 71 years (range, 26-95 years) and there were 437 men (63%). Hypertension was present in 453 patients (65%), diabetes in 128 patients (18%), prior myocardial infarction in 85 patients (12%), and prior stroke in 81 patients (12%). Prior coronary bypass grafting was performed in 212 patients (31%). Median left ventricular ejection fraction was 41% (range, 20-61) and New York Heart Association functional class III or IV was present in 529 patients (76%).

RESULTS

Biological valve re-replacement included most commonly aortic valve in 464 patients (67%) and mitral valve in 170 (24%). Concomitant coronary bypass grafting was performed in 134 patients (19%). Mortality at 30 days occurred in 56 patients (8%). Multivariable analysis with backward stepwise regression identified New York Heart Association functional class (per 1 increment) (hazard ratio, 2.1; 95% confidence interval, 1.06-4.3; P = .03) and prior coronary bypass grafting (hazard ratio, 3.5; 95% confidence interval, 1.2-10.9; P = .03) as independent predictors of early death. Patients with the combination of prior coronary bypass grafting and New York Heart Association functional class III or IV accounted for 26 out of 56 early deaths (46%) and in the absence of this combination, early death in the cohort was 30 out of 694 (4%). Follow-up was available in 602 out of 638 early survivors (94%) for a median of 45 months (range, 1 month-23.4 years). Survival at 5 and 10 years was 63% and 34%, respectively. For patients who died during follow-up, 2-dimensional scatter plots demonstrate durable length of postoperative survival (median, 5.5 years; maximum, 22 years).

CONCLUSIONS

In a large population of patients undergoing repeat biological valve replacement, prior coronary bypass grafting and advanced New York Heart Association functional class were associated with increased 30-day mortality, with the remaining population having a low 30-day mortality of 4%. This study could serve as a surgical benchmark to guide patient selection for transcatheter valve-in-valve technology rather than employing a broader application of these techniques to those who may otherwise have low early risk of mortality and durable long-term survival after conventional valve surgery.

1-Year Results in Patients Undergoing Transcatheter Aortic Valve Replacement With Failed Surgical Bioprostheses

OBJECTIVES

This study evaluated the safety and effectiveness of self-expanding transcatheter aortic valve replacement (TAVR) in patients with surgical valve failure (SVF).

BACKGROUND

Self-expanding TAVR is superior to medical therapy for patients with severe native aortic valve stenosis at increased surgical risk.

METHODS

The CoreValve U.S. Expanded Use Study was a prospective, nonrandomized study that enrolled 233 patients with symptomatic SVF who were deemed unsuitable for reoperation. Patients were treated with self-expanding TAVR and evaluated for 30-day and 1-year outcomes after the procedure. An independent core laboratory was used to evaluate serial echocardiograms for valve hemodynamics and aortic regurgitation.

RESULTS

SVF occurred through stenosis (56.4%), regurgitation (22.0%), or a combination (21.6%). A total of 227 patients underwent attempted TAVR and successful TAVR was achieved in 225 (99.1%) patients. Patients were elderly (76.7 ± 10.8 years), had a Society of Thoracic Surgeons Predicted Risk of Mortality score of 9.0 ± 6.7%, and were severely symptomatic (86.8% New York Heart Association functional class III or IV). The all-cause mortality rate was 2.2% at 30 days and 14.6% at 1 year; major stroke rate was 0.4% at 30 days and 1.8% at 1 year. Moderate aortic regurgitation occurred in 3.5% of patients at 30 days and 7.4% of patients at 1 year, with no severe aortic regurgitation. The rate of new permanent pacemaker implantation was 8.1% at 30 days and 11.0% at 1 year. The mean valve gradient was 17.0 ± 8.8 mm Hg at 30 days and 16.6 ± 8.9 mm Hg at 1 year. Factors significantly associated with higher discharge mean aortic gradients were surgical valve size, stenosis as modality of SVF, and presence of surgical valve prosthesis patient mismatch (all p < 0.001).

CONCLUSIONS

Self-expanding TAVR in patients with SVF at increased risk for surgery was associated with a low 1-year mortality and major stroke rate, significantly improved aortic valve hemodynamics, and low rates of moderate and no severe residual aortic regurgitation, with improved quality of life.

Transcatheter heart valve in valve implantation with Edwards SAPIEN bioprosthetic valve for different degenerated bioprosthetic valve positions (First Iranian ViV report with mid-term follow up)

Introduction: After early successful experience with transcatheter aortic valve replacement (TAVR), concept of transcatheter implantation of a new valve within a failing bioprosthetic valve emerged. Valve-in-valve (ViV) implantation seems to be a simpler option for high risk surgical patients.

Methods: We performed five ViV procedures in different valve positions. We included patients with failing bioprosthetic valves with high surgical risk due to concomitant comorbidities. We performed 2 transapical ViV procedures for failing mitral bioprosthetic valves, 1 transfemoral procedure for failing pulmonary valve and 2 transfemoral ViV implantation for failing tricuspid bioprosthetic valves.

Results: The procedures were successfully completed in all 5 cases with initial excellent fluoroscopic and echocardiographic verification. There was no valve embolization or paravalvular leakage in any of the cases. Transcatheter valve function was appropriate with echocardiography. Post procedural clinical adverse events like pleural effusion and transient ischemic attack were managed successfully. In midterm follow up all cases remained in appropriate functional class except from the transcatheter pulmonary valve which became moderately stenotic and regurgitant.

Conclusion: As the first Iranian all-comers case series with midterm follow up for ViV implantation, we had no mortality. Interestingly none of our patients had neurologic sequelae after the procedure. Midterm follow up for our patients was acceptable with good functional class and appropriate echocardiographic findings. Due to high surgical risk of the redo procedure after failing of a bioprosthetic valve especially in elderly patients with comorbidities, ViV implantation would be a good alternative to surgery for this high risk group.

Microstructural alterations owing to handling of bovine pericardium to manufacture bioprosthetic heart valves: A potential risk for cusp dehiscence

INTRODUCTION

Cross-linking and anti-calcification of prosthetic heart valves have been continuously improved to prevent degeneration and calcification. However, non-calcific structural deteriorations such as cuspal dehiscences along the stent still require further analysis.

MATERIAL AND METHOD

Based upon the previous analysis of an explanted valve after 7 years, a fresh commercial aortic valve was embedded in poly(methyl methacrylate) (PMMA) and cut into slices to ensure the detailed observation of the assembly and material structures. A pericardial patch embossed to provide the adequate shape of the cusps was investigated after paraffin embedding and appropriate staining. The microstructural damages that occurred during manufacturing process were identified and evaluated by light microscopy, polarized microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

RESULTS

The wavy collagen bundles, the key structure of the pericardium patch, were damaged to a great extent at suture sites along the stent and in the compressed areas around the stent post. The fixation of the embossed pericardium patch along the plots of the stent aggravated the microstructural modifications. The damages mainly appeared as the elimination of collagen bundle waviness and delamination between the bundles.

CONCLUSION

Considering the modes of failure of the explant, the damages to the collagen bundles may identify the vulnerable sites that play an important role in the cusp dehiscence of heart valve implants. Such information is important to the manufacturers. Recommendations to prevent in vivo cusp dehiscence can therefore be formulated.

Transcatheter aortic valve implantation: new hope in the management of valvular heart disease

Severe calcific aortic stenosis is relatively common, and unless treated with valve replacement it carries an adverse prognosis. A large number of patients, however, are denied surgery due to their advanced age or coexistent medical conditions that increase perioperative cardiovascular risks. Transcatheter aortic valve implantation (TAVI), a technique in which a bioprosthetic valve is inserted via a catheter and implanted within the diseased native aortic valve, is a new therapeutic modality for treatment of older patients with severe symptomatic aortic stenosis and other comorbidities, who have an inherently high surgical risk. This review will provide an overview of the pivotal trials in the development of TAVI; while also investigating important complications and limitations of the procedure and evaluating how new valves are being designed and clinically evaluated, with the ultimate goal of reducing potential complications and expanding the use of TAVI to lower-risk patient cohorts.

Factors influencing left ventricular outflow tract obstruction following a mitral valve-in-valve or valve-in-ring procedure, part 1

OBJECTIVES

To determine the factors influencing left ventricular outflow tract (LVOT) area reduction after a mitral valve-in-valve (VIV) or a valve-in-ring (VIR) procedure.

BACKGROUND

Transcatheter heart valves (THVs) are increasingly used in performing a VIV or a VIR procedure in high-risk patients. Although less invasive, a potential complication is LVOT obstruction. However, the factors predisposing to LVOT obstruction are ill defined.

METHODS AND RESULTS

To understand the effects of the various factors, the study was carried out in three parts: To understand the effect of VIV and VIR on reduction in LVOT area with special attention to different surgical heart valve (SHV) orientations and depth of THV implant. This was carried out in porcine and cadaver hearts. To quantify aorto-mitral-annular (AMA) angle in 20 patients with or without mitral disease and to derive a static computational model to predict LVOT obstruction. To study the effect of SHV design on LVOT obstruction after VIV. This was carried out as a bench test. LVOT area reduction was similar after VIV irrespective of orientation of the mitral SHV implantation as it pinned open the SHV leaflets. Similar effect was seen after VIR. The degree of LVOT obstruction was partly determined by AMAangle and was inversely proportional. SHV design, ring design, and depth of SPAIEN XT implantation also had effect on LVOT obstruction.

CONCLUSIONS

A possibility of LVOT obstruction should be considered when performing a VIV and VIR procedure. Type of SHV, flexible ring, less obtuse AMA angle, and depth of SAPIEN XT implant can influence the risk.

The expanding indications of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI), also known as transcatheter aortic valve replacement, is increasingly performed worldwide and is a technology that is here to stay. It has become the treatment of choice for inoperable patients and an alternative option for patients at high surgical risk with severe aortic stenosis. Early results of TAVI in intermediate-risk patients appear promising although larger randomized trial results are awaited before the widespread adoption of this technology in this big pool of patients. In patients with bicuspid aortic stenosis and degenerated surgical bioprostheses, TAVI has been shown to be feasible and relatively safe, though certain important considerations remain. Indications for TAVI are likely to grow as newer generation and improved devices and delivery systems become available.

Is the EuroSCORE II best suited for reoperative risk estimation in patients with structural deterioration of aortic bioprostheses?

BACKGROUND

Operative risk prediction systems (logistic EuroSCORE I, EuroSCORE II and STS Score) are employed together with multidisciplinary discussion to contraindicate conventional surgery in patients with valvular heart disease and propose the employment of alternative transcatheter procedures. The EuroSCORE I has been reported to underperform in these circumstances; we hypothesize that the EuroSCORE II is best suited for the stratification of risk in patients with structural deterioration (SVD) of valvular bioprostheses and potential candidates to the Valve-in-Valve procedure (deployment of a transcatheter valve within a failing valvular bioprosthesis).

METHODS AND EVALUATION OF THE HYPOTHESIS

A multi-institutional collaboration is required to fully address such hypothesis. Therefore, we performed a preliminary validation study by retrieval of the complete records of 81 patients undergoing reoperative aortic valve replacement for preoperative diagnosis of bioprosthetic SVD at our Institution. Logistic EuroSCORE I, EuroSCORE II and STS Score were calculated by preoperatively available data. Faced to an observed reoperative mortality of 4.9%, average EuroSCORE I was 15.8%±13.4, EuroSCORE II was 7.3%±7.4 and the STS Score was 15%±9.8. The three systems provided sufficient adequacy (Hosmer-Lemeshow p=0.847, p=0.999 and p=0.9948, respectively). Yet, the area under the ROC curve was significantly higher for the EuroSCORE II (0.9903) vs. the EuroSCORE I (0.8994) (p=0.044). The STS Score yielded an intermediate figure (0.9643). The odds ratios (logistic regression) were 1.079 for EuroSCORE I, 1.223 for the STS Score and 1.474 for EuroSCORE II.

CONCLUSIONS

The three investigated algorithms showed reasonable calibration in the prediction of mortality for reoperative aortic valve replacement, but they evenly overestimated the observed mortality. The hypothesis that the EuroSCORE II is better suited for the selection of candidates to Valve-in-Valve implantation is worth of further multi-institutional investigations on the basis of our preliminary findings and due to the expanding role of transcatheter techniques.

Transcatheter aortic valve implantation

Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease.

Transcatheter valve-in-valve implantation: a systematic review of literature

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) has become an alternative to open surgery in those deemed high risk. The purpose of this study was to evaluate the effectiveness and outcomes of this emerging procedure. We have examined available literature to provide an overview of valve-in-valve implantation using transcatheter heart valves (THVs) in aortic, mitral, pulmonary, tricuspid positions.

METHODS

A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science.

RESULTS

Only 61 studies met full criteria and were included the review. This included 31 studies reporting transcatheter aortic valve-in-valve implantation, mitral valve-in-valve implantation (13 studies), tricuspid valve-in-valve implantation (12 studies), and pure native aortic valve regurgitation (nine studies). One of the limitations of this review is that most of the studies included were case reports, together with some case series.

CONCLUSION

Valve-in-valve implantation can be considered as an acceptable alternative to conventional open heart surgery for elderly high-risk surgical patients with bioprosthetic degeneration. Long-term follow-up of treated patients will be necessary to establish the true role of valve-in-valve implantation for bioprosthetic degeneration. Patients should be evaluated on an individual basis until outcomes are proven in large cohort studies or randomised trials.

Transcatheter aortic valve replacement: historical perspectives, current evidence, and future directions

Severe aortic stenosis (AS) results in considerable morbidity and mortality without aortic valve replacement and is expected to increase in prevalence with the aging population. Because AS primarily affects the elderly, many patients with comorbidities are poor candidates for surgical aortic valve replacement (SAVR) and may not be referred. Transcatheter aortic valve replacement (TAVR) has emerged as transformative technology for the management of AS over the past decade. Randomized trials have established the safety and efficacy of TAVR with improved mortality and quality of life compared with medical therapy in inoperable patients, while demonstrating noninferiority and even superiority to SAVR among high-risk operative candidates. However, early studies demonstrated an early penalty of stroke and vascular complications with TAVR as well as increased paravalvular leak as compared with SAVR. Two device platforms have been evaluated and approved for use in the United States: the Edwards SAPIEN and the Medtronic CoreValve. Early studies also suggest cost-effectiveness for TAVR. Ongoing studies are evaluating new iterations of the aforementioned TAVR devices, novel device designs, and applications of TAVR in expanded populations of patients including those with lower risk profiles as well as those with comorbidities that were excluded from early clinical trials. Future improvements in TAVR technology will likely reduce periprocedural and long-term complications. Further studies are needed to confirm device durability over long-term follow-up and explore the applicability of TAVR to broader AS patient populations.

Evolution of Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement emerged ≈20 years ago and changed the landscape of structural interventional cardiology. The first experiments in animal models provided proofs of the concept and the substrate for the first percutaneous valve implantation in patients. The initial promising results in a clinical setting drew the attention of the industry and of the scientific community, and an effort was made for the past 12 years to address the limitations of the technology, facilitate the procedure, minimize the risk of complications, and broaden the applications of transcatheter aortic valve replacement. This article reviews the evolution of transcatheter aortic valve replacement, presents the first steps in this field, cites the evidence from registries and clinical trials, highlights the limitations of this treatment, and discusses the future perspectives and the developments proposed to address the current pitfalls.

Valve-in-valve implantations: is this the new standard for degenerated bioprostheses? Review of the literature

Transcatheter aortic valve implantation has established itself as an alternative treatment for patients with valvular disease. In the current context of increasing bioprosthetic valve implants and an ageing population with growing comorbidities, a less invasive approach to the treatment of bioprosthetic dysfunction would be an appealing alternative to the standard of care. Transcatheter valve-in-valve implantation could be an alternative for patients who are deemed to be a high surgical risk. The valve-in-valve procedure is a minimally invasive percutaneous procedure where a valve can be implanted directly within a failing bioprosthetic valve. This technique can be applied to dysfunctional aortic bioprosthetic valves and can also be used in the pulmonary and atrioventricular valve bioprosthesis. We review the current literature to assess whether this technique may be the new standard for degenerated bioposthesis.