Evolution of Transcatheter Aortic Valve Replacement

Closing the care gap: combining enhanced recovery with minimally invasive valve surgery

PURPOSE OF REVIEW

Patients with advanced age and frailty require interventions for structural heart disease at an increasing rate. These patients typically experience higher rates of postoperative morbidity, mortality and prolonged hospital length of stay, loss of independence as well as associated increased costs to the healthcare system. Therefore, it is becoming critically important to raise awareness and develop strategies to improve clinical outcomes in the contemporary, high-risk patient population undergoing cardiacprocedures.

RECENT FINDINGS

Percutaneous options for structural heart disease have dramatically improved the therapeutic options for some older, frail, high-risk patients; however, others may still require cardiac surgery. Minimally invasive techniques can reduce some of the physiologic burden experienced by patients undergoing surgery and improve recovery. Enhanced Recovery After Cardiac Surgery (ERAS Cardiac) is a comprehensive, interdisciplinary, evidence-based approach to perioperative care. It has been shown to improve recovery and patient satisfaction while reducing complications and length of stay.

SUMMARY

Combining minimally invasive cardiac surgery with enhanced recovery protocols may result in improved patient outcomes for a patient population at high risk of morbidity and mortality following cardiac surgery.

TAVR in Older Adults: Moving Toward a Comprehensive Geriatric Assessment and Away From Chronological Age: JACC Family Series

Calcific aortic stenosis can be considered a model for geriatric cardiovascular conditions due to a confluence of factors. The remarkable technological development of transcatheter aortic valve replacement was studied initially on older adult populations with prohibitive or high-risk for surgical valve replacement. Through these trials, the cardiovascular community has recognized that stratification of these chronologically older adults can be improved incrementally by invoking the concept of frailty and other geriatric risks. Given the complexity of the aging process, stratification by chronological age should only be the initial step but is no longer sufficient to optimally quantify cardiovascular and noncardiovascular risk. In this review, we employ a geriatric cardiology lens to focus on the diagnosis and the comprehensive management of aortic stenosis in older adults to enhance shared decision-making with patients and their families and optimize patient-centered outcomes. Finally, we highlight knowledge gaps that are critical for future areas of study.

Transcatheter aortic valve durability, predictors of bioprosthetic valve dysfunction, longer-term outcomes - a review

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is one of the most significant inventions in cardiology, as it provides a viable minimally invasive treatment option for patients with aortic stenosis, the most common valvular disease in the developed world and one with a poor prognosis when left untreated. Using data available to date, this review aims to discuss and identify possible predictors of TAVI valve durability - an essential requirement for the device's wide-spread use, especially in younger patients.

AREAS COVERED

This article explores the main causes of bioprosthetic valve dysfunction (BVD) based on pathophysiology and available data, and reviews possible predictors of BVD including prosthesis-related, procedure-related, and patient-related factors. An emphasis is made on affectable predictors, which could potentially be targeted with prevention management and improve valve durability. A literature search of online medical databases was conducted using relevant key words and dates; significant clinical trials were identified. A brief overview of important randomized controlled trials with mid to long-term follow-up is included in this article.

EXPERT OPINION

Identifying modifiable predictors of valve dysfunction presents an opportunity to enhance and predict valve durability - a necessity as patients with longer life-expectancies are being considered for the procedure.

Short-term outcome after transcatheter aortic valve replacement with a novel balloon-expandable valve

OBJECTIVES

Transcatheter aortic valve replacement (TAVR) has been expanding rapidly with numerous transcatheter heart valve (THV) systems currently available. The Myval balloon-expandable (BE) valve (Meril Life Sciences Pvt. Ltd., India) is a novel THV system indicated for the treatment of patients with severe aortic stenosis. The primary objective of this study is to assess the safety and performance of the Myval BE valve.

METHODS

In this prospective single-centre study, 120 consecutive patients who underwent TAVR with the Myval BE valve were included. Clinical outcomes were evaluated at 30 days and 6 months using Valve Academic Research Consortium‑2 criteria. All-cause mortality, stroke, acute kidney injury, major vascular complications, moderate or severe paravalvular leakage (PVL) and need for a permanent pacemaker implantation (PPI) were investigated.

RESULTS

At 6‑month follow-up, all-cause death and cardiac death were seen in 5.8% and 0.8% of the patients respectively. Periprocedural stroke and need for PPI were both seen in 3.3% of the patients. Access-site-related vascular and bleeding complications were absent. Improved valve haemodynamics and no moderate to severe PVL could be seen at 30 days. An intermediate valve size was selected in 51% of the patients.

CONCLUSIONS

The Myval BE valve demonstrates improved valve haemodynamics, absence of moderate to severe PVL and good safety outcomes at 6‑month follow-up with low cardiac death rate and acceptable rates of permanent pacemaker implantation and periprocedural stroke. Future randomised controlled trials will further establish the clinical utility of the Myval BE valve.

App-based assessment of memory functions in patients after transfemoral aortic valve replacement

BACKGROUND

Transfemoral aortic valve replacement (TAVR) is the standard treatment for elderly patients with aortic valve stenosis. Although safe and well-established, there is a risk of intraprocedural hemodynamic instability and silent cerebral embolism, which can lead to a decline in neurocognitive function and dementia. In clinical practice, comprehensive cognitive testing is difficult to perform. AI-assisted digital applications may help to optimize diagnosis and monitoring.

METHODS

Neurocognitive function was assessed by validated psychometric tests using "∆elta -App", which uses artificial intelligence and computational linguistic methods for extraction and analysis. Memory function was assessed using the 'Consortium to Establish a Registry for Alzheimer's Disease' (CERAD) word list and digit span task (DST) before TAVR and before hospital discharge. The study is registered in the German Register of Clinical Trials (https://drks.de/search/de/trial/DRKS00020813).

RESULTS

From October 2020 until March 2022, 141 patients were enrolled at University Hospital Heart Centre Brandenburg. Mean age was 81 ± 6 years, 42.6% were women. Time between the pre- and post-interventional test was on average 6 ± 3 days. Memory function before TAVR was found to be below average in relation to age and educational level. The pre-post TAVR comparison showed significant improvements in the wordlist repeat, P < 0.001 and wordlist recall test of CERAD, P < 0.001. There were no changes in the digital span test.

CONCLUSIONS

Despite impaired preoperative memory function before TAVR, no global negative effect on memory function after TVAR was detected. The improvements shown in the word list test should be interpreted as usual learning effects in this task.

Minimal Access Aortic Valve Surgery

Minimally invasive approaches to the aortic valve have been described since 1993, with great hopes that they would become universal and facilitate day-case cardiac surgery. The literature has shown that these procedures can be undertaken with equivalent mortality rates, similar operative times, comparable costs, and some benefits regarding hospital length of stay. The competing efforts of transcatheter aortic valve implantation for these same outcomes have provided an excellent range of treatment options for patients from cardiology teams. We describe the current state of the art, including technical considerations, caveats, and complications of minimal access aortic surgery and predict future directions in this space.

Assessing the Novel Myval Balloon-Expandable Valve with the Evolut Valve: A Propensity-Matched Study

BACKGROUND

The Myval balloon-expandable (BE) valve has shown encouraging early clinical data in terms of safety and efficacy. Comparative data with other well-established contemporary valves are nonetheless still scarce. This study aims to compare the performance of the Myval BE valve with the Evolut self-expanding (SE) valve.

METHODS

In this retrospective single-center study, 223 patients with symptomatic severe aortic stenosis (AS) were included and treated with the Myval BE valve (n = 120) or with the Evolut SE valve (n = 103). Then, 91 pairs were compared after matching. Clinical outcomes were evaluated at 30 days and 1 year. Echocardiographic follow-up was performed at 30 days.

RESULTS

Procedural complications were rare in both groups. At the 30-day follow-up, no significant difference in cardiac death (Myval: 1% vs. Evolut: 2%, p = 0.56), stroke (2% vs. 4%, p = 0.41) and myocardial infarction (1% vs. 3%, p = 0.31) was observed. A permanent pacemaker implantation (PPI) was significantly less needed in the Myval group (4% vs. 15%, p = 0.01). At 1 year, cardiac death (2% vs. 4%, p = 0.41) and the stroke rate (7% vs. 5%, p = 0.76) were similar. Moderate-severe paravalvular leakage (PVL) was also comparable in both groups (1% vs. 4%, p = 0.17).

CONCLUSION

Safety and efficacy outcomes were comparable between the two valves, except for a higher PPI rate for the Evolut SE valve. Up to 1-year follow-up, clinical outcomes showed acceptable rates of stroke and cardiac death with both valves. Valve hemodynamics were excellent with a low rate of moderate-severe PVL in both groups.

Impact of TAVR on coronary artery hemodynamics using clinical measurements and image-based patient-specific in silico modeling

In recent years, transcatheter aortic valve replacement (TAVR) has become the leading method for treating aortic stenosis. While the procedure has improved dramatically in the past decade, there are still uncertainties about the impact of TAVR on coronary blood flow. Recent research has indicated that negative coronary events after TAVR may be partially driven by impaired coronary blood flow dynamics. Furthermore, the current technologies to rapidly obtain non-invasive coronary blood flow data are relatively limited. Herein, we present a lumped parameter computational model to simulate coronary blood flow in the main arteries as well as a series of cardiovascular hemodynamic metrics. The model was designed to only use a few inputs parameters from echocardiography, computed tomography and a sphygmomanometer. The novel computational model was then validated and applied to 19 patients undergoing TAVR to examine the impact of the procedure on coronary blood flow in the left anterior descending (LAD) artery, left circumflex (LCX) artery and right coronary artery (RCA) and various global hemodynamics metrics. Based on our findings, the changes in coronary blood flow after TAVR varied and were subject specific (37% had increased flow in all three coronary arteries, 32% had decreased flow in all coronary arteries, and 31% had both increased and decreased flow in different coronary arteries). Additionally, valvular pressure gradient, left ventricle (LV) workload and maximum LV pressure decreased by 61.5%, 4.5% and 13.0% respectively, while mean arterial pressure and cardiac output increased by 6.9% and 9.9% after TAVR. By applying this proof-of-concept computational model, a series of hemodynamic metrics were generated non-invasively which can help to better understand the individual relationships between TAVR and mean and peak coronary flow rates. In the future, tools such as these may play a vital role by providing clinicians with rapid insight into various cardiac and coronary metrics, rendering the planning for TAVR and other cardiovascular procedures more personalized.

Body Mass Index and Mortality from Nonrheumatic Aortic Valve Disease among Japanese Men and Women

AIM

We aimed to examine the impact of overweight and obesity on mortality from nonrheumatic aortic valve disease.

METHODS

In the Japan Collaborative Cohort Study, we analyzed data of 98,378 participants aged 40-79 years, with no history of coronary heart disease, stroke, or cancer at baseline (1988-1990) and who completed a lifestyle questionnaire including height and body weight; they were followed for mortality until the end of 2009. The Cox proportional hazards model was used to calculate the multivariable hazard ratios (HRs) with 95% confidence intervals (CIs) of nonrheumatic aortic valve disease mortality according to body mass index (BMI) after adjusting for potential confounding factors.

RESULTS

During the median 19.2 years follow-up, 60 deaths from nonrheumatic aortic valve disease were reported. BMI was positively associated with the risk of mortality from nonrheumatic aortic valve disease; the multivariable HRs (95% CIs) were 0.90 (0.40-2.06) for persons with BMI ＜21 kg/m², 1.71 (0.81-3.58) for BMI 23-24.9 kg/m², 1.65 (0.69-3.94) for BMI 25-26.9 kg/m², and 2.83 (1.20-6.65) for BMI ≥ 27 kg/m² (p for trend=0.006), compared with persons with BMI 21-22.9 kg/m². Similar associations were observed between men and women (p for interaction=0.56). Excluding those who died during the first ten years of follow-up or a competing risk analysis with other causes of death as competing risk events did not change the association materially.

CONCLUSIONS

Overweight and obesity may be independent risk factors for nonrheumatic aortic valve disease mortality in Asian populations.

A Brief History of Cardiothoracic Surgical Critical Care Medicine in the United States

Cardiothoracic surgical intensive care has developed in response to advances in cardiothoracic surgery. The invention of the cardiopulmonary bypass machine facilitated a motionless and bloodless surgical field and made operations of increasing complexity feasible. By the mid-1950s, the first successful procedures utilizing cardiopulmonary bypass took place. This was soon followed by the establishment of postoperative recovery units, the precursors to current cardiothoracic surgical intensive care units. These developments fostered the emergence of a new medical specialty: the discipline of critical care medicine. Together, surgeons and intensivists transformed the landscape of acute, in-hospital care. It is important to celebrate these achievements by remembering the individuals responsible for their conception. This article describes the early days of cardiothoracic surgery and cardiothoracic intensive care medicine.

The application of 3D printing in preoperative planning for transcatheter aortic valve replacement: a systematic review

Background

Recently, transcatheter aortic valve replacement (TAVR) has been suggested as a less invasive treatment compared to surgical aortic valve replacement, for patients with severe aortic stenosis. Despite the attention, persisting evidence suggests that several procedural complications are more prevalent with the transcatheter approach. Consequently, a systematic review was undertaken to evaluate the application of three-dimensional (3D) printing in preoperative planning for TAVR, as a means of predicting and subsequently, reducing the incidence of adverse events.

Methods

MEDLINE, Web of Science and Embase were searched to identify studies that utilised patient-specific 3D printed models to predict or mitigate the risk of procedural complications.

Results

13 of 219 papers met the inclusion criteria of this review. The eligible studies have shown that 3D printing has most commonly been used to predict the occurrence and severity of paravalvular regurgitation, with relatively high accuracy. Studies have also explored the usefulness of 3D printed anatomical models in reducing the incidence of coronary artery obstruction, new-onset conduction disturbance and aortic annular rapture.

Conclusion

Patient-specific 3D models can be used in pre-procedural planning for challenging cases, to help deliver personalised treatment. However, the application of 3D printing is not recommended for routine clinical practice, due to practicality issues.

Transcatheter Heart Valves: A Biomaterials Perspective

Heart valve disease is prevalent throughout the world, and the number of heart valve replacements is expected to increase rapidly in the coming years. Transcatheter heart valve replacement (THVR) provides a safe and minimally invasive means for heart valve replacement in high-risk patients. The latest clinical data demonstrates that THVR is a practical solution for low-risk patients. Despite these promising results, there is no long-term (>20 years) durability data on transcatheter heart valves (THVs), raising concerns about material degeneration and long-term performance. This review presents a detailed account of the materials development for THVRs. It provides a brief overview of THVR, the native valve properties, the criteria for an ideal THV, and how these devices are tested. A comprehensive review of materials and their applications in THVR, including how these materials are fabricated, prepared, and assembled into THVs is presented, followed by a discussion of current and future THVR biomaterial trends. The field of THVR is proliferating, and this review serves as a guide for understanding the development of THVs from a materials science and engineering perspective.

New Model for the Assessment of Transcatheter Aortic Valve Replacement Devices in Sheep

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is an effective therapy in treating high-risk patients suffering from aortic stenosis. Animal models used to evaluate safety and efficacy of TAVR devices prior to clinical use lack a stenotic aortic annulus, a critical impediment to long-term TAVR device evaluation. We sought to create a reproducible model of aortic stenosis using a modified aortic annuloplasty (MAA) procedure in sheep, followed by deployment and long-term evaluation of TAVR devices using this model.

METHODS

Twelve sheep underwent the MAA procedure and were recovered. Transthoracic echocardiography (TTE) was used to monitor changes in the aortic annulus in the postoperative period. At 60 days post-MAA, Test group animals were anesthetized for TAVR insertion and Control animals underwent a necropsy. Test animals were recovered following TAVR insertion and observed for a postoperative period of 140 days.

RESULTS

Twelve sheep survived the annuloplasty procedure and the 60-day recovery period. Gross examination of seven Control group animals revealed the implanted annuloplasty ring segments formed hard protrusions into the aortic annulus. Five sheep in the Test group underwent successful deployment of Abbott's experimental TAVR device without evidence of migration. Examination at 140 days post-TAVR insertion showed all devices tightly anchored within the modified aortic annulus.

CONCLUSIONS

The MAA procedure creates stenotic segments in the aortic annulus with adequate rigidity for anchorage and long-term evaluation of TAVR devices. This represents the first model that successfully mimics human aortic stenosis and provides a clinically relevant TAVR deployment platform for long-term evaluation in sheep.

Evolution of outcome and complications in TAVR: a meta-analysis of observational and randomized studies

Aim of the present analysis was to collect and pool all available data currently in the literature regarding outcomes and complications of all approved TAVR prosthesis and to assess the transition from first to next generation TAVR devices by directly comparing both in regard of procedure related complications. Transcatheter aortic valve replacement is a well established treatment modality in patients with severe aortic stenosis deemed to be inoperable or at unacceptable risk for open heart surgery. First generation prostheses were associated with a high rate of peri-procedural complications like paravalvular regurgitation, valve malpositioning, vascular complications and conduction disorders. Refinement of the available devices incorporate features to address the limitations of the first-generation devices. A PRISMA checklist-guided systematic review and meta-analysis of prospective observational studies, national and device specific registries or randomized clinical trials was conducted. Studies were identified by searching PUBMED, SCOPUS, Cochrane Central Register of Controlled Trials and LILACs from January 2000 to October 2017. We extracted and pooled data on both mortality and complications from 273 studies for twelve different valves prostheses in a total of 68,193 patients. In second generation prostheses as compared to first generation devices, we observed a significant decrease in mortality (1.47 ± 1.73% vs. 5.41 ± 4.35%; p < 0.001), paravalvular regurgitation (1.75 ± 2.43vs. 12.39 ± 9.38, p < 0.001) and MACE. TAVR with contemporary next generation devices has led to an impressive improvement in TAVR safety driven by refined case selection, improved procedural techniques and increased site experience.

Myval transcatheter heart valve system in the treatment of severe symptomatic aortic stenosis

The transcatheter aortic valve replacement (TAVR) is an established treatment for patients with severe symptomatic aortic stenosis (AS) at prohibitive risk for surgery. It is an alternative treatment to surgical aortic valve replacement in patients with AS at intermediate- and high-surgical risk. Although regulatory authorities extend the indications of TAVR to treat patients at low-surgical risk, the limitations of earlier-generation transcatheter heart valve (THV) systems accelerate the development of improved newer generation of THV systems. Myval™ THV (Meril Life Sciences Pvt. Ltd., Vapi, Gujarat, India) is a newer-generation, balloon-expandable TAVR system with features that facilitate accurate positioning of the bioprosthetic valve and favorable procedural and clinical outcomes. This review summarizes existing preclinical and clinical data on Myval THV for the intervention of symptomatic native AS and lays out the plan for future research program.

The evolution of device technology in transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has rapidly evolved and changed the landscape of structural interventional cardiology. Advances in transcatheter heart valve (THV) prostheses and TAVI-enabling devices have simplified the procedure, reduced the risk of complications, improved short- and long-term outcomes and broadened the applications of TAVI, not only in challenging patients and complex anatomies but also in intermediate-risk or even in low-risk patients, where surgical valve replacement constitutes an effective and well-established therapy. In this review article, we provide an overview of the developments in TAVI devices which have played a vital role in TAVI evolution: we describe the prostheses that failed to reach clinical practice, we present the characteristics of the first valves that were tested in the clinical arena, we summarise the evidence from the first studies that highlighted the potential but also the limitations of TAVI, and we present the advanced next-generation THV prostheses that have an improved performance and safety profile.

Correlation Between Aortic Angulation and Outcomes of Transcatheter Aortic Valve Replacement With New-Generation Valves

The aim of this study was to assess the correlation of aortic angulation (AA) on immediate postprocedural and long-term outcomes following transcatheter aortic valve replacement (TAVR) with new-generation valves. There is limited and conflicting data on the impact of AA on short- and long-term outcomes in patients undergoing TAVR. Available studies to date were done with first-generation valves. We assessed 179 patients who underwent TAVR with either a balloon-expandable or self-expandable valve at our institute from May 2014 to June 2017 and had multislice computed tomography scans available for AA evaluation. All included patients received a second- or third-generation valve. TAVR endpoints, device success, and adverse events were defined according to the Valve Academic Research Consortium-2 criteria. The mean AA of the study population was 49.05 ± 10.07. Patients were divided into 2 groups: AA <49 and AA ≥49, and then further subdivided by valve type. There were no difference in mean age, The Society for Thoracic Surgery (STS) score, or race distribution between the AA <49 and AA ≥49 groups. The preimplantation balloon valvuloplasty rate was higher in patients with AA ≥ 49 compared to patients with AA <49, (70% vs 55.1%, P = 0.04). There was no difference in re-hospitalization, pacemaker implantation, postprocedural aortic regurgitation or mortality between patients with AA <49 and AA ≥49 irrespective of valve type (P < 0.05). AA does not significantly affect short- or long-term outcomes in patients who undergo TAVR with new-generation balloon-expandable or self-expandable valves.

The Red Kangaroo pericardium as a material source for the manufacture of percutaneous heart valves

BACKGROUND

The kangaroo pericardium might be considered to be a good candidate material for use in the manufacture of the leaflets of percutaneous heart valves based upon the unique lifestyle. The diet consists of herbs, forbs and strubs. The kangaroo pericardium holds an undulated structure of collagen.

MATERIAL AND METHOD

A Red Kangaroo was obtained after a traffic fatality and the pericardium was dissected. Four compasses were cut from four different sites: auricular (AUR), atrial (ATR), sternoperitoneal (SPL) and phrenopericardial (PPL). They were investigated by means of scanning electron microscopy, light microscopy and transmission electron microscopy.

RESULTS

All the samples showed dense and wavy collagen bundles without vascularisation from both the epicardium and the parietal pericardium. The AUR and the ATR were 150±25μm thick whereas the SPL and the PPL were thinner at 120±20μm. The surface of the epicardium was smooth and glistening. The filaments of collagen were well individualized without any aggregation, but the banding was poorly defined and somewhat blurry.

CONCLUSION

This detailed morphological analysis of the kangaroo pericardium illustrated a surface resistant to thrombosis and physical characteristics resistant to fatigue. The morphological characteristics of the kangaroo pericardium indicate that it represents an outstanding alternative to the current sources e.g., bovine and porcine. However, procurement of tissues from the wild raises supply and sanitary issues. Health concerns based upon sanitary uncertainty and reliability of supply of wild animals remain real problems.

Anatomic and procedural associations of transcatheter heart valve displacement following Evolut R implantation

OBJECTIVES

This study aimed to predict the displacement of self-expanding transcatheter heart valves (THV) during final deployment.

BACKGROUND

Accurate device positioning during transcatheter aortic valve implantation (TAVI) is crucial for optimal results.

METHODS

At our institution, 103 patients who underwent transfemoral TAVI with Evolut R were retrospectively identified. Multiple linear regression models were created, and a predictor equation was built to quantify the factors that may affect THV behavior.

RESULTS

Multiple linear regression analysis for THV displacement on the left coronary cusp (LCC) identified the angle between the THV and the ascending aorta (ATA), predilation, and less operator experience as independent predictors of upward displacement, whereas estimated glomerular filtration rate (eGFR) was inversely related with THV behavior (95% confidence interval: 0.219 to 0.340, 0.447 to 2.092, 0.165 to 1.757, and -0.053 to -0.011, respectively). Predictors of THV displacement on the noncoronary cusp side could not be identified using this model.

CONCLUSIONS

The ATA at the point of recapture, predilation, and less operator experience were independent predictors of upward displacement of THV on the LCC side. eGFR was an independent predictor of THV downward displacement on the LCC side. Of them, the ATA was the strongest predictor. Physicians may need to adjust this angle adequately before deployment to achieve the appropriate position.

Pre-procedural fit-testing of TAVR valves using parametric modeling and 3D printing

BACKGROUND

Successful transcatheter aortic valve replacement (TAVR) requires an understanding of how a prosthetic valve will interact with a patient's anatomy in advance of surgical deployment. To improve this understanding, we developed a benchtop workflow that allows for testing of physical interactions between prosthetic valves and patient-specific aortic root anatomy, including calcified leaflets, prior to actual prosthetic valve placement.

METHODS

This was a retrospective study of 30 patients who underwent TAVR at a single high volume center. By design, the dataset contained 15 patients with a successful annular seal (defined by an absence of paravalvular leaks) and 15 patients with a sub-optimal seal (presence of paravalvular leaks) on post-procedure transthoracic echocardiogram (TTE). Patients received either a balloon-expandable (Edwards Sapien or Sapien XT, n = 15), or a self-expanding (Medtronic CoreValve or Core Evolut, n = 14, St. Jude Portico, n = 1) valve. Pre-procedural computed tomography (CT) angiograms, parametric geometry modeling, and multi-material 3D printing were utilized to create flexible aortic root physical models, including displaceable calcified valve leaflets. A 3D printed adjustable sizing device was then positioned in the aortic root models and sequentially opened to larger valve sizes, progressively flattening the calcified leaflets against the aortic wall. Optimal valve size and fit were determined by visual inspection and quantitative pressure mapping of interactions between the sizer and models.

RESULTS

Benchtop-predicted "best fit" valve size showed a statistically significant correlation with gold standard CT measurements of the average annulus diameter (n = 30, p < 0.0001 Wilcoxon matched-pairs signed rank test). Adequateness of seal (presence or absence of paravalvular leak) was correctly predicted in 11/15 (73.3%) patients who received a balloon-expandable valve, and in 9/15 (60%) patients who received a self-expanding valve. Pressure testing provided a physical map of areas with an inadequate seal; these corresponded to areas of paravalvular leak documented by post-procedural transthoracic echocardiography.

CONCLUSION

We present and demonstrate the potential of a workflow for determining optimal prosthetic valve size that accounts for aortic annular dimensions as well as the active displacement of calcified valve leaflets during prosthetic valve deployment. The workflow's open source framework offers a platform for providing predictive insights into the design and testing of future prosthetic valves.

Transcatheter Aortic Valve Replacement: Efficiency and Safety Improvements With Progressive Experience and Improved Technology

OBJECTIVE

Transcatheter aortic valve replacement is now commercially available for intermediate-risk, high-risk, or inoperable patients with severe aortic stenosis. In this study, we investigated change in the safety and efficiency of the transcatheter aortic valve replacement procedure at our institution and patient outcomes comparing our first 100, second 100, and last 100 patients.

METHODS

From March 2012 to June 2016, 544 patients underwent transcatheter aortic valve replacement at our center. Three hundred patients were selected for this study and were categorized in the following three groups: group A, first to 100th patient; group B, 101st to 200th patient; and group C, 444th to 544th patient. Preoperative, intraoperative, and postoperative data were collected.

RESULTS

Three hundred patients, 162 male (54%) male and 138 female (46%) with a mean ± SD age of 79.10 ± 8.93 years and mean ± SD society of thoracic surgeons' risk score of 7.47 ± 0.76 were included. Fluoroscopy time, operation time, and incision time significantly decreased form group A to group C (all P < 0.05). Mean of contrast volume was also the highest in group A and the lowest in group C (P < 0.001). Acute kidney injury rate was 26% (n = 26) in group A versus 23% (n = 23) in group B (P = 0.743), and only one patient in group C (group C vs. group B, P < 0.001). Strokes declined over time: five (5%) stroke in group A; two (2%) stroke in group B, and no patient in group C (group C vs. group B, P = 0.1, and group C vs. group A, P = 0.059). In-hospital mortality was 5% (n = 5) in group A, 4% (n = 4) in group B, and 1% in group C (P = 0.21).

CONCLUSIONS

Progressive experience and technology advances with transcatheter aortic valve replacement procedures improved operators' expertise, making the transcatheter aortic valve replacement more efficient and safer over time.

Transcatheter heart valve for aortic valve implantation: republication of the article published in the Japanese Journal of Artificial Organs

This review was created based on a translation of the Japanese review first reported in the Japanese Journal of Artificial Organs in 2015 (vol. 44, no. 3, pp. 136-140), with some modifications.

Transcatheter aortic valve implantation at a high-volume center: the Bad Rothenfelde experience

Introduction

The “transfemoral (TF) first” approach to access route selection in transcatheter aortic valve implantation (TAVI) is popular; however, the risk of major vascular complications is substantial. The “best for TF” approach identifies only the patients with ideal anatomy for TF-TAVI, potentially minimizing complications.

Aim

To characterize the outcomes of patients undergoing TAVI at a large-volume site that employs this approach.

Material and methods

Patients who underwent TAVI at the Bad Rothenfelde Heart Centre between 2008 and 2016 were consecutively enrolled. Findings were compared to those from large, multicenter registries.

Results

Of the 1,644 patients enrolled, 1,140 underwent TA- and 504 TF-TAVI. Comorbidities were more frequent in TA patients, who also had higher risk scores (EuroSCORE: 25.5% vs. 21.2%; STS score: 11.0% vs. 7.5%; p < 0.001 for both). Rates of conversion to open surgery, major vascular complications and intra-procedural mortality did not differ between groups. At 30 days, mortality rates were higher in the TA group (3.9% vs. 1.9%, p = 0.036). Stroke/transient ischemic attack and permanent pacemaker implantation rates did not differ significantly between groups (2.0% and 9.1% overall, respectively). Compared to multicenter registries, trends in mortality and complication rates were similar, though magnitudes were lower in the present study. In contrast with the present study, major vascular complication rates in multicenter registries are significantly higher for TF compared to TA patients.

Conclusions

At this high-volume center, the use of a “best for TF” approach to TAVI resulted in low mortality and complication rates.

Correlation between structural changes and acute thrombogenicity in transcatheter pericardium valves after crimping and balloon deployment

INTRODUCTION

Transcathether heart valve replacement has gained considerable acceptance during the last decades. It is now part of the armamentarium for aortic valve replacement. The procedure proved to be highly efficient. However the issues of the blood compatibility and tissue durability were not raised and the adverse events were probably under-reported, according to observations of thrombosis after deployment.

MATERIAL AND METHOD

Bovine pericardium leaflets were sewn inside a 26mm diameter stainless steel stent to manufacture these valves (one control and two experimental). The correlation between the trauma and the acute thombogenicity of bovine pericardium leaflets, after crimping and ballooning, was investigated via an in vitro blood flow with labeled platelets. These leaflets were processed for histology: scanning electron microscopy, light microscopy, and transmission electron microscopy.

RESULTS

The control specimens showed a regular pericardium structure with some blood cells deposited on the collagen fibrous surface (inflow) and scarce blood cells deposited on the serous surface (outflow). After crimping and ballooning, the structure of the pericardium was severely injured, eventually with delaminations and ruptures. The blood cell uptake was considerably increased compared to the control.

CONCLUSION

It would therefore be appropriate to pay more attention to the design of the valves. Specifically, the incorporation of a buffer tissue or fabric between the pericardium and the metallic stent is suggested. The issue of ballooning deserves detailed and in depth investigation regarding the lifetime of the device.

Transcatheter heart valve crimping and the protecting effects of a polyester cuff

INTRODUCTION

Prior to deployment, the percutaneous heart valves must be crimped and loaded into sheaths of diameters that can be as low as 6mm for a 23mm diameter valve. However, as the valve leaflets are fragile, any damage caused during this crimping process may contribute to reducing its long-term durability in vivo.

MATERIAL AND METHOD

Bovine pericardium percutaneous valves were manufactured as follows. The leaflets were sutured on a nitinol frame. A polyester cuff fabric served as a buffer between the pericardium and the stent. Two valves were crimped and one valve was used as control. The valves were examined in gross observation and micro-CT scan and then the leaflets were processed for histology and analyzed in scanning electron microscopy, light microscopy and transmission electron microscopy.

RESULT

Crimping of the valves resulted in the increase thickness of the leaflets and there was no evidence of additional delamination. The heavy prints of the stents were irregularly distributed on the outflow surface in the crimped devices and were shallow and did not penetrate throughout the thickness of the leaflets. However, the wavy microscopy of collagen fiber bundles was well preserved. They were found to remain individualized without any agglutination as shown by the regular banding appearance.

CONCLUSION

Crimping of self-deployable valves per se caused only minor damages to the leaflets. However, the procedure could be refined in order to minimize areas of high pressure and swelling of the tissue that can be accompanied with flow surface disruption and increase of the hydraulic conductance. The incorporation of a polyester buffer serves to prevent the deleterious effects that may be caused if the pericardium tissue were in direct contact with the nitinol stent.

Morphology, Clinicopathologic Correlations, and Mechanisms in Heart Valve Health and Disease

The clinical and pathological features of the most frequent intrinsic structural diseases that affect the heart valves are well established, but heart valve disease mechanisms are poorly understood, and effective treatment options are evolving. Major advances in the understanding of the structure, function and biology of native valves and the pathobiology, biomaterials and biomedical engineering, and the clinical management of valvular heart disease have occurred over the past several decades. This communication reviews contemporary considerations relative to the pathology of valvular heart disease, including (1) clinical significance and epidemiology of valvular heart disease; (2) functional and dynamic valvular macro-, micro- and ultrastructure; (3) causes, morphology and mechanisms of human valvular heart disease; and (4) pathologic considerations in valve replacement, repair and, potentially, regeneration of the heart valves.

Aortic Angulation Attenuates Procedural Success Following Self-Expandable But Not Balloon-Expandable TAVR

OBJECTIVES

The aim of this study was to evaluate the impact of increased aortic angulation (AA) on acute procedural success following transcatheter aortic valve replacement (TAVR).

BACKGROUND

The degree of angulation between the aorta and the heart can make accurate positioning of the bioprosthesis during TAVR more demanding, particularly in instances of an extremely angulated or horizontal aortic root. Nonetheless, there are limited data on the impact of AA on the acute success of TAVR.

METHODS

We assessed 582 patients who underwent TAVR at our institute and had contrast computed tomography available for AA evaluation. TAVR endpoints, device success, and adverse events were considered according to the Valve Academic Research Consortium-2 definitions.

RESULTS

The mean angulation of the aorta was 47.3 ± 8.7°. Patients were therefore divided into 2 groups: AA <48° and AA ≥48°. AA in the 480 patients who underwent balloon-expandable (BE) TAVR did not influence acute procedural success or short-term clinical outcome. In contrast, increased AA among the 102 patients who underwent self-expandable (SE) TAVR was found to significantly attenuate procedural success (area under the curve: 0.73; 95% confidence interval: 0.61 to 0.85; p = 0.008). The numerical cutoff for AA with the highest sum of sensitivity and specificity for device success was ≥48° (sensitivity 85%, specificity 61%). Moreover, patients whose AA was ≥48° were also associated with an increased need for a second valve and post-dilation, had increased fluoroscopy time and increased valve embolization, and had increased post-procedural paravalvular regurgitation greater than or equal to mild following SE TAVR. Major complications at 30 days, including mortality were similar between AA groups. Six-month mortality was also similar between both AA groups.

CONCLUSIONS

Increased aortic root angulation adversely influences acute procedural success following SE but not BE TAVR. Because of these data, BE valves may be preferred when evaluating patients with high AA before TAVR.

Heart valve health, disease, replacement, and repair: a 25-year cardiovascular pathology perspective

The past several decades have witnessed major advances in the understanding of the structure, function, and biology of native valves and the pathobiology and clinical management of valvular heart disease. These improvements have enabled earlier and more precise diagnosis, assessment of the proper timing of surgical and interventional procedures, improved prosthetic and biologic valve replacements and repairs, recognition of postoperative complications and their management, and the introduction of minimally invasive approaches that have enabled definitive and durable treatment for patients who were previously considered inoperable. This review summarizes the current state of our understanding of the mechanisms of heart valve health and disease arrived at through innovative research on the cell and molecular biology of valves, clinical and pathological features of the most frequent intrinsic structural diseases that affect the valves, and the status and pathological considerations in the technological advances in valvular surgery and interventions. The contributions of many cardiovascular pathologists and other scientists, engineers, and clinicians are emphasized, and potentially fruitful areas for research are highlighted.

Assessment of quality of life in patients after surgical and transcatheter aortic valve replacement

OBJECTIVES

Transcatheter aortic valve implantation (TAVI) and minimally invasive aortic valve replacement (mini-thoracotomy, mini-sternotomy, MIAVR) have become an appealing alternative to conventional surgical (SAVR) treatment of severe aortic stenosis (AS) in high-risk patients.

BACKGROUND

Aim of the study was to evaluate the quality of life (QoL) in patients with AS and treated with transfemoral TAVI, SAVR, mini-thoracotomy and mini-sternotomy.

METHODS

One hundred and seventy-three patients with symptomatic AS were enrolled in 2011-2013. TAVI group consisted of 39 patients (22.5%), mini-sternotomy was performed in 44 patients (25.5%), mini-thoracotomy in 50 (29%), and AVR in 40 patients (23%). QoL was assessed perioperatively, 12 and 24 months after aortic valve replacement (AVR) by Minnesota Living with Heart Failure Questionnaire (MLHFQ) and EQ-5D-3L.

RESULTS

Median follow-up was 583.5 (IQR: 298-736) days. Improvement of health status after procedure in comparison with pre-operative period was significantly more often reported after TAVI in perioperative period (90.3%; P = 0.004) and 12 months after procedure (100%, P = 0.02). Global MLHFQ, physical and emotional dimension score at 30-day from AVR presented significant improvement after TAVI in comparison with surgical methods (respectively: 8.3(±8.6), P = 0.003; 4.1(±5.9), P = 0.01; 1.5(±2.6), P = 0.005). Total MLHFQ score was significantly lower (better outcome) in TAVI patients 1 year after procedure (4.8(±6.8), P = 0.004), no differences in somatic and emotional component were found. No differences were found in MLHFQ score 24 months after AVR. Data from EQ-D5-3L questionnaire demonstrated significant improvement of QoL at 30-day follow-up after TAVI in comparison with surgical methods (1.2(±1.7), P = 0.0008).

CONCLUSIONS

TAVI improves QoL in perioperative and 12 months observation in comparison with mini-thoracotomy, mini-sternotomy and SAVR. Improvement in QoL was obtained in both generic and disease specific questionnaires. © 2016 Wiley Periodicals, Inc.

In vitro study of coronary flow occlusion in transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has been developed recently for patients with high morbidities and who are believed to be not tolerate standard surgical aortic valve replacement. Nevertheless, the TAVI is associated with complications such as potential obstruction of coronary ostia, mitral valve insufficiency, and stent migration although it seems promising. Impairment of the coronary blood flow after TAVI is catastrophic and it was believed to be associated with the close position of the coronary orifice and the aortic leaflets and valve stent. However, few data was available as to the anatomic relationship between valve stent and aortic root anatomic structures including the coronary arterial ostia, aortic leaflets.

METHODS

The aortic roots were observed in 40 hearts specimens. The width of aortic leaflet, height of aortic sinus annulus to the sinutubular junction (STJ), distance between aortic sinus annulus to its corresponding coronary ostia, and coronary arterial ostia to its corresponding STJ level were measured. Moreover, the relationships of valve stent, aortic leaflets and coronary ostia before/post stent implantation and after the open of aorta were evaluated respectively.

RESULTS

Approximate three quarters of the coronary ostia were located below the STJ level. The mean distances from left, right and posterior aortic sinus annulus to the related STJ level was comparable, which was 18.5±2.7, 18.9±2.6, 18.7±2.6 mm, respectively. Meanwhile, the height of left and right aortic sinus annulus to its corresponding coronary ostia was 16.6±2.8 and 17.2±3.1 mm for left and right side respectively.

CONCLUSIONS

Most of the coronary ostia were located below the STJ level and could be covered by the leaflets. This highlights the need of modified stents to prevent occlusion of coronary flow after TAVI.