Development of transcatheter aortic valve implantation (TAVI): a 20-year odyssey

Is Transcatheter Aortic Valve Implantation (TAVI) Activity in Australia Consistent With International Guidelines?

BACKGROUND

Transcatheter aortic valve implantation (TAVI) did not receive regulatory approval in Australia until 2013, several years after Europe (2007) and America (2011). Consequently, the uptake of TAVI in Australia initially lagged behind international best practices. This study was undertaken to provide an update on the status of TAVI activity in Australia.

METHOD

A descriptive population-level epidemiological study was performed. Annual activity data for both surgical aortic valve replacement (SAVR) and TAVI were obtained from the Australian Institute of Health and Welfare (AIHW) for the period from 1 July 2012 to 30 June 2022. Dynamic contemporaneous population data were obtained from the Australian Bureau of Statistics (ABS). Trends in absolute activity, population-adjusted activity and age cohort-adjusted activity were examined.

RESULTS

Despite the impact of the COVID-19 pandemic on the Australian healthcare system, TAVI activity has continued to increase. Annual TAVI activity now exceeds annual SAVR activity (3,967 vs 3,870), albeit driven by TAVI in patients aged 85+ years. Population-adjusted TAVI activity now exceeds the reported European average (15.3 vs 14.1 per 100,000 persons). The point of equipoise for the choice between SAVR and TAVI is the 75-79 age cohort (50% vs 50%).

CONCLUSIONS

Australian TAVI activity is now consistent with international best practice.

Safety and feasibility of early discharge after transcatheter aortic valve implantation with ACURATE Neo-the POLESTAR trial

BACKGROUND

Transcatheter aortic valve implantation (TAVI) serves a growing range of patients with severe aortic stenosis (AS). TAVI has evolved to a streamlined procedure minimizing length of hospital stay.

AIMS

To evaluate the safety and efficacy of an early discharge (ED) strategy after TAVI.

METHODS

We performed an international, multi-center, prospective observational single-arm study in AS patients undergoing TAVI with the ACURATE valve platform. Eligibility for ED was assessed prior to TAVI and based on prespecified selection criteria. Discharge ≤ 48 h was defined as ED. Primary Valve Academic Research Consortium (VARC)-3-defined 30-day safety and efficacy composite endpoints were landmarked at 48 h and compared between ED and non-ED groups.

RESULTS

A total of 252 patients were included. The median age was 82 [25th-75th percentile, 78-85] years and the median Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score was 2.2% [25th-75th percentile, 1.6-3.3]. ED and non-ED were achieved in 173 (69%) and 79 (31%) patients respectively. Monitoring for conduction disturbances was the principal reason for non-ED (33%). Overall, at 30 days, all-cause mortality was 1%, new permanent pacemaker rate was 4%, and valve- or procedure-related rehospitalization was 4%. There was no difference in the primary safety and efficacy endpoint between the ED and non-ED cohorts (OR 0.84 [25th-75th percentile, 0.31-2.26], p = 0.73, and OR 0.97 [25th-75th percentile, 0.46-2.06], p = 0.94). The need for rehospitalization was similarly low for ED and non-ED groups.

CONCLUSION

Early discharge after TAVI with the ACURATE valve is safe and feasible in selected patients. Rhythm monitoring and extended clinical observation protracted hospital stay.

Impact of Procedure Volume on the Outcomes of Surgical Aortic Valve Replacement

BACKGROUND

 Literature demonstrated that procedure volumes affect outcomes of patients undergoing transcatheter aortic valve implantation. We evaluated the outcomes of surgical aortic valve replacement.

METHODS

 All isolated surgical aortic valve replacement procedures in Germany in 2017 were identified. Hospitals were divided into five groups from ≤25 (very low volume) until >100 (very high volume) annual procedures.

RESULTS

 In 2017, 5,533 patients underwent isolated surgical aortic valve replacement. All groups were of comparable risk (logistic EuroSCORE, 5.12-4.80%) and age (66.6-68.1 years). In-hospital mortality and complication rates were lowest in the very high-volume group. Multivariable logistic regression analyses showed no significant volume-outcome relationship for in-hospital mortality, stroke, postoperative delirium, and mechanical ventilation > 48 hours. Regarding acute kidney injury, patients in the very high-volume group were at lower risk than those in the very low volume group (odds ratio [OR] = 0.53, p = 0.04). Risk factors for in-hospital mortality were previous cardiac surgery (OR = 5.75, p < 0.001), high-grade renal disease (glomerular filtration rate < 15 mL/min, OR = 5.61, p = 0.002), surgery in emergency cases (OR = 2.71, p = 0.002), and higher grade heart failure (NYHA [New York Heart Association] III/IV; OR = 1.80, p = 0.02). Risk factors for all four complication rates were atrial fibrillation and diabetes mellitus.

CONCLUSION

 Patients treated in very low volume centers (≤25 operations/year) had a similar risk regarding in-hospital mortality and most complications compared with very high-volume centers (>100 operations/year). Only in the case of acute kidney injury, very high-volume centers showed better outcomes than very low volume centers. Therefore, surgical aortic valve replacement can be performed safely independent of case volume.

The Application of Precision Medicine in Structural Heart Diseases: A Step towards the Future

The personalized applications of 3D printing in interventional cardiology and cardiac surgery represent a transformative paradigm in the management of structural heart diseases. This review underscores the pivotal role of 3D printing in enhancing procedural precision, from preoperative planning to procedural simulation, particularly in valvular heart diseases, such as aortic stenosis and mitral regurgitation. The ability to create patient-specific models contributes significantly to predicting and preventing complications like paravalvular leakage, ensuring optimal device selection, and improving outcomes. Additionally, 3D printing extends its impact beyond valvular diseases to tricuspid regurgitation and non-valvular structural heart conditions. The comprehensive synthesis of the existing literature presented here emphasizes the promising trajectory of individualized approaches facilitated by 3D printing, promising a future where tailored interventions based on precise anatomical considerations become standard practice in cardiovascular care.

Predictive Value of the Modified Mehran Score for Contrast-Induced Nephropathy After Transcatheter Aortic Valve Implantation

Considering the increasing use of the transcatheter aortic valve implantation (TAVI) procedure, the relationship of contrast-induced nephropathy (CIN) with post-TAVI mortality has become important. The Mehran score was developed to detect the risk of CIN development after cardiac intervention. We aimed to compare the role of the modified Mehran score, which can be calculated pre-procedure, in predicting CIN development and compare it with the original Mehran score. We retrospectively collected data from TAVI procedures at our institution between December 2016 and June 2021; of 171 patients, 44 (25.7%) had CIN. We found no association between contrast media volume and CIN (387 ± 120 vs 418 ± 139 mL, P = .303). High and very high modified Mehran score and preoperative C-reactive protein (CRP) level were independent risk factors for CIN development after TAVI procedure. The area under curve (AUC) was .686 with 95% CI: .591-.780 and P < .001, and also, with a cut-off point of >7.5 points, there was 79.5% sensitivity and 63.0% specificity; otherwise, with a cut-off point of >9.5 points, there was 54.5% sensitivity and 71.7% specificity, for the modified Mehran score. The modified Mehran score comes into prominence compared with the original Mehran score since it can be calculated pre-procedure.

Third-Generation Transcatheter Aortic Heart Valve with Reverse Parachute Sealing Cuff in Patients with Aortic Valve Disease

BACKGROUND

The Navitor (Abbott Inc, IL, USA) transcatheter heart valve is a novel third-generation self-expanding bioprosthesis with specific features to mitigate paravalvular regurgitation (PVR). Owing to its novelty, there is a paucity of data on its application in clinical practice.

METHODS

Consecutive cohort analysis of the use of the Navitor system in an as-treated clinical setting at a quaternary heart hospital.

RESULTS

Sixty consecutive non-clinical trial patients treated with Navitor were identified. All patients underwent a successful procedure. The mean age was 79.3 years (±SD 7.82), 56.67% (n=34) were female, and the mean STS score was 4.87 (±SD 5.70). At 30 days post-procedure, all patients were alive with no readmissions for heart failure. One patient had a major vascular complication (1.7%). Four patients (7.14% of patients without a pre-existing pacemaker) received a new permanent pacemaker. Two patients (3.4%) had a non-disabling stroke. PVR at 30 days was trivial or none in 75% of patients, and no patient had worse than mild PVR.

CONCLUSIONS

The Navitor system in this as-treated cohort was associated with favourable clinical, haemodynamic, and safety outcomes.

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.

Urgent versus Non-Urgent Transcatheter Aortic Valve Implantation Outcomes

INTRODUCTION

There are limited data about the outcomes of nonelective transcatheter aortic valve implantation (TAVI). Some studies suggest that these patients (pts) have worst results. Our purpose was to compare outcomes in pts submitted to urgent versus elective TAVI.

METHODS

Retrospective analysis of 298 consecutive pts submitted to TAVI between 2018 and 2021 in a single tertiary center. Baseline characteristics and outcomes were collected and compared between elective and nonelective TAVI.

RESULTS

Pts submitted to urgent TAVI (79 pts) had worse baseline characteristics, with higher EuroScore risk (9.26 vs. 5.17%, p < 0.0001), STS score (7.09 vs. 4.4%, p < 0.0001), and NT pro-natriuretic peptide B (10,168 vs. 3,241 pg/mL, p = 0.001), lower left ventricle ejection fraction (45 vs. 52%, p = 0.003), more diabetes (46.8 vs. 32.4%, p = 0.0.22), peripheral artery disease (21.5 vs. 6.8%, p < 0.0001), and poor vascular accesses (18.4 vs. 7.4%, p = 0.007). Urgent TAVI was associated with higher mortality (25.3 vs. 15.1%, p = 0.043), 30-day cardiovascular mortality (17.5 vs. 4%, p = 0.001), life-threatening bleeding (11.5 vs. 4.1%, p = 0.018), vascular complications (11.5 vs. 4.6%, p = 0.031), and longer hospital stay (28 vs. 12 days, p < 0.0001), but not with intensive care unit or post-TAVI hospital stay (5 vs. 4 days, p = 0.197 and 11 vs. 10 days, p = 0.572). When adjusted to differences in baseline characteristics, urgent TAVI was only associated with longer hospital stay (p < 0.0001).

CONCLUSION

Pts submitted to urgent TAVI have worse short-term outcomes, but this seems to be attributable to the worse baseline characteristics instead of the urgent nature of the procedure.

A Systematic Review and Statistical Analysis of Factors Influencing the Cost-Effectiveness of Transcatheter Aortic Valve Implantation for Symptomatic Severe Aortic Stenosis

Objective

Transcatheter aortic valve implantation (TAVI) is a disruptive technology recommended for patients with symptomatic severe aortic stenosis (sSAS). Despite being available for over 15 years in Europe, with an extensive volume of clinical and economic evaluations across all surgical risk groups, there is little evidence on the identification of the key drivers of TAVI's cost-effectiveness. This study sought to identify these factors and quantify their role.

Methods

A systematic literature review was conducted to identify published economic evaluations of TAVI. This was supplemented by health technology assessment reports. The primary outcome was the likelihood of TAVI being found cost-effective. Secondary outcomes of TAVI being dominant, and the incremental health benefits of TAVI were also explored.

Results

Forty-two studies, reporting 65 unique analyses, were identified. TAVI was found to be cost-effective and dominant in 74% and 20% of analyses, respectively. The latest generation balloon-expandable TAVI device (SAPIEN 3) was more likely to be found cost-effective, as was TAVI use in low-risk populations and when performed via transfemoral access route. There was heterogeneity in the approach taken to economic modelling, which may also influence estimates of cost-effectiveness. Analyses that found TAVI to be dominant always compared it to surgery and usually considered the latest generation balloon-expandable TAVI device. Largest health benefits were observed for the inoperable risk group.

Conclusion

For patients with sSAS, TAVI is typically a cost-effective treatment option. There are important differences by device generation, risk group and access route. It is crucial to consider these differences when appraising the health economic evidence-base for TAVI.

Outcomes and predictors of periprocedural stroke after transcatheter aortic valve implantation

BACKGROUND

Risk factors for stroke after transcatheter aortic valve implantation (TAVI) are currently incompletely understood.

PURPOSE

To identify possible predictors of early post-TAVI stroke and explore its short-term outcomes.

METHODS

Retrospective analysis of consecutive patients (pts) submitted to TAVI between 2009 and 2020 in a tertiary center. Baseline characteristics, procedural information and stroke in first 30 days after TAVI were collected. In-hospital and 12 months outcomes were analyzed.

RESULTS

A total of 512pts (56,1% female, mean age of 82 ± 6years.) were included. In the first 30 days after TAVI 19pts (3,7%) had a stroke. In univariate analysis stroke was associated with higher body mass index (29 vs 27kg/m², p=0.035), higher triglyceridemia (> 117,5mg/dL, p=0,002), lower high-density lipoprotein (< 38,5mg/dL, p=0,009) and porcelain aorta (36,8% vs 15,5%, p=0,014) and more frequent use of post-dilatation (58,8% vs 32%, p=0,021). In multivariate analysis, triglycerides > 117,5mg/dL (p=0,032, OR = 3,751) and post-dilatation (p=0,019, OR = 3,694) were the independent predictors. Stroke after TAVI was associated with longer intensive care unit stay (12 vs 4 days, p<0,001) and post-TAVI hospital stay (25 vs 10 days, p<0,0001), higher intra-hospital mortality (21,1% vs 4,3%, p=0,003), cardiovascular 30-day mortality (15,8% vs 4,1%, p=0,026) and 1-year stroke (13,2% vs 1,1%, p=0,003).

CONCLUSION

Periprocedural and 30-day stroke is a relatively uncommon but potentially devastating complication after TAVI. In this cohort, 30-day stroke rate after TAVI was 3.7%. Hypertriglyceridemia and post-dilatation were found to be the only independent risk predictors. Outcomes after stroke, including 30-day mortality, were significantly worse.

Flaw-insensitive fatigue resistance of chemically fixed collagenous soft tissues

Bovine pericardium (BP) has been used as leaflets of prosthetic heart valves. The leaflets are sutured on metallic stents and can survive 400 million flaps (~10-year life span), unaffected by the suture holes. This flaw-insensitive fatigue resistance is unmatched by synthetic leaflets. We show that the endurance strength of BP under cyclic stretch is insensitive to cuts as long as 1 centimeter, about two orders of magnitude longer than that of a thermoplastic polyurethane (TPU). The flaw-insensitive fatigue resistance of BP results from the high strength of collagen fibers and soft matrix between them. When BP is stretched, the soft matrix enables a collagen fiber to transmit tension over a long length. The energy in the long length dissipates when the fiber breaks. We demonstrate that a BP leaflet greatly outperforms a TPU leaflet. It is hoped that these findings will aid the development of soft materials for flaw-insensitive fatigue resistance.

Treatment of pure aortic regurgitation using surgical or transcatheter aortic valve replacement between 2018 and 2020 in Germany

Background

In pure aortic regurgitation, transcatheter aortic valve replacement (TAVR) is not yet used on a regular base. Due to constant development of TAVR, it is necessary to analyze current data.

Methods

By use of health records, we analyzed all isolated TAVR or surgical aortic valve replacements (SAVR) for pure aortic regurgitation between 2018 and 2020 in Germany.

Results

4,861 procedures-4,025 SAVR and 836 TAVR-for aortic regurgitation were identified. Patients treated with TAVR were older, showed a higher logistic EuroSCORE, and had more pre-existing diseases. While results indicate a slightly higher unadjusted in-hospital mortality for transapical TAVR (6.00%) vs. SAVR (5.71%), transfemoral TAVR showed better outcomes, with self-expanding compared to balloon-expandable transfemoral TAVR having significantly lower in-hospital mortality (2.41% vs. 5.17%; p = 0.039). After risk adjustment, balloon-expandable as well as self-expanding transfemoral TAVR were associated with a significantly lower mortality vs. SAVR (balloon-expandable: risk adjusted OR = 0.50 [95% CI 0.27; 0.94], p = 0.031; self-expanding: OR = 0.20 [0.10; 0.41], p < 0.001). Furthermore, the observed in-hospital outcomes of stroke, major bleeding, delirium, and mechanical ventilation >48 h were significantly in favor of TAVR. In addition, TAVR showed a significantly shorter length of hospital stay compared to SAVR (transapical: risk adjusted Coefficient = -4.75d [-7.05d; -2.46d], p < 0.001; balloon-expandable: Coefficient = -6.88d [-9.06d; -4.69d], p < 0.001; self-expanding: Coefficient = -7.22 [-8.95; -5.49], p < 0.001).

Conclusions

TAVR is a viable alternative to SAVR in the treatment of pure aortic regurgitation for selected patients, showing overall low in-hospital mortality and complication rates, especially with regard to self-expanding transfemoral TAVR.

Similar clinical outcomes with transcatheter aortic valve implantation and surgical aortic valve replacement in octogenarians with aortic stenosis

Background

Transcatheter aortic valve implantation (TAVI) is the preferred treatment option for severe aortic stenosis in the elderly and in patients with comorbidities. We sought to compare outcomes after TAVI and surgical aortic valve replacement (SAVR) in octogenarians.

Methods

In this retrospective cohort study conducted at our tertiary center, clinical data were gathered before and after TAVI and SAVR procedures performed from January 2013 to May 2019; follow-up completed in March 2021. The primary outcome was 1-year mortality. Patients were stratified according to Society of Thoracic Surgeons (STS) score and procedure type. Propensity score-based matching was also performed.

Results

Of 542 patients who matched the inclusion criteria, 273 underwent TAVI and 269 SAVR. TAVI patients were older (85.8 ± 3.0 vs. 82.2 ± 2.2 years; P &lt; 0.001) and had a higher mean STS score (5.0 ± 4.0 vs. 2.8 ± 1.3; P &lt; 0.001) and EuroSCORE II (5.3 ± 4.1 vs. 2.8 ± 6.0; P &lt; 0.001). Rates of postoperative permanent pacemaker insertion (15.0% vs. 9.3%; P = 0.040) and paravalvular leak (9.9% vs. 0.8%; P &lt; 0.001) were higher and acute kidney injury lower (8.8% vs. 32.7%; P &lt; 0.001) after TAVI, with no difference between treatment groups for major bleeding (11.0% vs. 6.7%; P = 0.130) or 30-day mortality (5.5% vs. 3.7%; P = 0.315). A statistically significant difference was found between TAVI and SAVR in low- and intermediate-risk groups when it came to occurrence of paravalvular leak, acute kidney injury, and new onset AF (all P &lt; 0.001).

Conclusion

This analysis of an octogenarian “real-life” population undergoing TAVI or SAVR (with a biological valve) showed similar outcomes regarding clinical endpoints in low- and medium-risk (STS score) groups.

Hospital intervention volume affects outcomes of emergency transcatheter aortic valve implantations in Germany

The literature has shown an inverse volume-outcome relationship for transcatheter aortic valve implantation (TAVI). However, little is known about emergency admissions in Germany. Using German national electronic health records, we identified all isolated balloon-expandable and self-expanding transfemoral TAVI in 2018. The focus was on those patients with emergency admission. 17,295 patients were treated with TAVI, including 1682 emergency cases. 49.2% of the emergency admissions were female, the mean age was 81.2 years and the logistic EuroSCORE was 23.3%. The percentage of emergency cases was higher in lower volume than in higher volume centers (p < 0.001): In detail, centers performing < 50 TAVI showed an emergency admission rate of ~ 15%, those with > 200 TAVI a rate of ~ 11%. After propensity score adjustment, analyzing the outcomes for an increase in volume per 10 emergency admissions, higher volume centers showed significantly better outcomes regarding in-hospital mortality (OR = 0.872, p = 0.043), major bleeding (OR = 0.772, p = 0.001), stroke (OR = 0.816, p = 0.044), mechanical ventilation > 48 h (OR = 0.749, p = 0.001), length of hospital stay (risk adjusted difference in days of hospitalization per 10 emergency admissions: - 1.01 days, p < 0.001), and reimbursement (risk adjusted difference in reimbursement per 10 emergency admissions: -€314.89, p < 0.001). Results were not significant for acute kidney injury (OR = 0.951, p = 0.104), postoperative delirium (OR = 0.975, p = 0.480), and permanent pacemaker implantation (OR = 1.010, p = 0.732). In conclusion, regarding transfemoral TAVI, the percentage of emergency cases was higher in lower volume centers in Germany. However, higher volume centers show significantly better outcomes for in-hospital mortality and complication rates as well as resource utilization parameters.

Technical Aspects and Development of Transcatheter Aortic Valve Implantation

Aortic stenosis is the most common valve disease requiring surgery or percutaneous treatment. Since the first-in-man implantation in 2002 we have witnessed incredible progress in transcatheter aortic valve implantation (TAVI). In this article, we review the technical aspects of TAVI development with a look at the future. Durability, low thrombogenicity, good hydrodynamics, biocompatibility, low catheter profile, and deployment stability are the attributes of an ideal TAVI device. Two main design types exist-balloon-expandable and self-expanding prostheses. Balloon-expandable prostheses use a cobalt-chromium alloy frame providing high radial strength and radiopacity, while the self-expanding prostheses use a nickel-titanium (Nitinol) alloy frame, which expands to its original shape once unsheathed and heated to the body temperature. The valve is sewn onto the frame and consists of the porcine or bovine pericardium, which is specially treated to prevent calcinations and prolong durability. The lower part of the frame can be covered by polyethylene terephthalate fabric or a pericardial skirt, providing better sealing between the frame and aortic annulus. The main future challenges lie in achieving lower rates of paravalvular leaks and new pacemaker implantations following the procedure, lower delivery system profiles, more precise positioning, longer durability, and a good hemodynamic profile. Patient-specific design and the use of autologous tissue might solve these issues.

Trends in Mortality From Aortic Stenosis in Europe: 2000-2017

Background: Trends in mortality from aortic stenosis across European countries are not well-understood, especially given the significant growth in transcatheter aortic valve implantation (TAVI) in the last 10 years. Methods: Age-standardised death rates were extracted from the World Health Organisation Mortality Database, using the International Classification of Diseases 10th edition code for non-rheumatic aortic stenosis for those aged > 45 years between 2000 and 2017. The UK and countries from the European Union with at least 1,000,000 inhabitants and at least 50% available datapoints over the study period were included: a total of 23 countries. Trends were described using Joinpoint regression analysis. Results: No reductions in mortality were demonstrated across all countries 2000-2017. Large increases in mortality were found for Croatia, Poland and Slovakia for both sexes (>300% change). Mortality plateaued in Germany from 2008 in females and 2012 in males, whilst mortality in the Netherlands declined for both sexes from 2007. Mortality differences between the sexes were observed, with greater mortality for males than females across most countries. Conclusions: Mortality from aortic stenosis has increased across Europe from 2000 to 2017. There are, however, sizable differences in mortality trends between Eastern and Western European countries. The need for health resource planning strategies to specifically target AS, particularly given the expected increase with ageing populations, is highlighted.

Comparing Trajectory of Surgical Aortic Valve Replacement in the Early vs. Late Transcatheter Aortic Valve Replacement Era

Background: Traditionally, the only effective treatment for aortic stenosis was surgical aortic valve replacement (SAVR). Transcatheter aortic valve replacement (TAVR) was approved in the United States in late 2011 and provided a critical alternative therapy. Our aims were to investigate the trends in the utilization of SAVR in the early vs. late TAVR era and to assess SAVR and TAVR outcomes. Methods: Using the 2011-2017 National Inpatient Sample database, we identified hospitalizations for patients with a most responsible diagnosis of aortic stenosis during which an aortic valve replacement (AVR) was performed, either SAVR or TAVR. Patients' sociodemographic and clinical characteristics, procedure complications, length of stay, and mortality were analyzed. Multivariable analyses were performed to identify predictors of in-hospital mortality. Piecewise regression analyses were performed to assess temporal trends in SAVR and TAVR utilization. Results: A total of 542,734 AVR procedures were analyzed. The utilization of SAVR was steady until 2014 with a significant downward trend in the following years 2015-2017 (P = 0.026). In contrast, a steady upward trend was observed in the TAVR procedure with a significant increase during the years 2015-2017 (P = 0.006). Higher in-hospital mortality was observed in SAVR patients. The mortality rate declined from 2011 to 2017 in a significantly higher proportion in the TAVR compared with the SAVR group. Conclusion: Utilization of SAVR showed a downward trend during the late TAVR era (2015-2017), and TAVR utilization demonstrated a steady upward trend during the years 2011-2017. Higher in-hospital mortality was recorded in patients who underwent SAVR.

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.

Similarity measures and attribute selection for case-based reasoning in transcatheter aortic valve implantation

In a clinical decision support system, the purpose of case-based reasoning is to help clinicians make convenient decisions for diagnoses or interventional gestures. Past experience, which is represented by a case-base of previous patients, is exploited to solve similar current problems using four steps-retrieve, reuse, revise, and retain. The proposed case-based reasoning has been focused on transcatheter aortic valve implantation to respond to clinical issues pertaining vascular access and prosthesis choices. The computation of a relevant similarity measure is an essential processing step employed to obtain a set of retrieved cases from a case-base. A hierarchical similarity measure that is based on a clinical decision tree is proposed to better integrate the clinical knowledge, especially in terms of case representation, case selection and attributes weighting. A case-base of 138 patients is used to evaluate the case-based reasoning performance, and retrieve- and reuse-based criteria have been considered. The sensitivity for the vascular access and the prosthesis choice is found to 0.88 and 0.94, respectively, with the use of the hierarchical similarity measure as opposed to 0.53 and 0.79 for the standard similarity measure. Ninety percent of the suggested solutions are correctly classified for the proposed metric when four cases are retrieved. Using a dedicated similarity measure, with relevant and weighted attributes selected through a clinical decision tree, the set of retrieved cases, and consequently, the decision suggested by the case-based reasoning are substantially improved over state-of-the-art similarity measures.

Rapid development of an iatrogenic aortic dissection following transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) represents a catheter-based and minimally invasive replacement of the aortic valve. TAVI is considered to be a relatively safe procedure and has evolved to a standard procedure in inoperable and high-risk patients with aortic stenosis. We present a case of an octogenarian who died in hospital less than a day after an initially satisfactory TAVI. Cardiologists suspected a combination of cardiogenic and hemorrhagic shock as the cause of death. Autopsy showed rupture of an extensive aortic dissection, which had developed within 24 h after the procedure. The cause of death was eventually defined as internal bleeding due to a rapid two-stage vascular process. The manner of death was considered accidental because an iatrogenic vessel injury beyond the aortic arch was causative for the death. This unusual case highlights the potential for rare, but fatal, complications within the scope of cardiac catheterizations, such as TAVI. Additionally, our findings suggest that these complications need to be recognized in the diagnostic process and management of post-interventional complications.

Pressurized Perfusion System for Obtaining Completely Acellular Pulmonary Valve Scaffolds for Tissue Engineering

Introduction. Xenogeneic tissues decellularization represents the obtaining process of extracellular matrix derived scaffolds. Most antigens being cell based, non-immunogenicity is obtained by cells removal. Scaffolds are temporary structures with biologic and mechanical role. Scaffolds, stem cells and bioreactors represent premise of regenerative medicine, aiming towards the ideal valvular substitute. In previous studies, we decellularized pulmonary valves root by immersion histology revealing cellular residue, requiring a more efficient approach. We hypothesized that immersion is insufficient and thus a pressure gradient was added.

Material and Method. This is part of a grant approved by the UMFTS. Eleven porcine pulmonary valves were included in the study: n=6 underwent immersion decellularization and n=5 were cyclically perfused with a 20-25mmHg pressure gradient during a 10-day protocol. The acellular valves obtained underwent a quality control using DAPI (4′,6-diamidino-2-phenylindol) nuclear staining, histological Haematoxylin-Eosin, DNA extraction and quantification, harvested from different structural levels: arterial wall, sinus, cusp.

Results. Histological assessments highlighted integrity of extracellular matrix in both groups and overall cells absence at the different levels of valvular structures analyzed. Immersion decellularized valves exhibited DAPI positive structures identified as potential residual nucleic material. Comparatively, the perfusion decellularized valves, lacked in those structures, result confirmed by DNA extraction and quantitation procedure.

Conclusions. Perfusion decellularization represents a feasible approach to obtain acellular cardiac valvular scaffolds derived from the extracellular matrix, being superior to immersion decellularization method. Their nonimmunogenic potential is underlined by total absence of nuclei. The process is fast, allowing production of an abundant number of valvular biomaterials in a short time.

QT Dispersion Changes after Transcatheter Aortic Valve Implantation in Patients with Aortic Stenosis

Objective

The aim of this study was to evaluate the QT dispersion and echocardiographic parameters in patients before and after transcatheter aortic valve implantation (TAVI).

Methods

One hundred and fifty-two patients with severe aortic valve stenosis (AS) were included in our study. Ninety five patients who underwent aortic valve replacement with TAVI were included in the TAVI group and 57 patients, who refused TAVI, were included in the medical treatment group. The QT interval and echocardiographic parameters of all patients were assessed before and after the procedure (first and sixth months and first year). The QT intervals were taken from the onset of the QRS to the end of the T wave.

Results

All patients had severe AS. The average mean aortic valve gradient was 46.1±12. Left ventricular internal diastolic diameter (LVIDD) and interventricular septum diastolic thickness (IVSDT) did not change significantly after TAVI (P>0.05). QT dispersion, corrected QT dispersion, and mean aortic valve gradient changed significantly six months after TAVI (P<0.05). Compared to the medical treatment group, QT dispersion and corrected QT dispersion were significantly decreased at the sixth month in the TAVI group. The incidence of malignant arrhythmias was smaller in the TAVI group than in the medical treatment group. The mortality rate was lower at the first-year follow-up in the TAVI group than in the medical treatment group.

Conclusion

Increased QT dispersion is associated with severe symptomatic AS. After TAVI, QT dispersion reduces.

Fabrication and characterization of a large medical balloon with ultra-high strength

BACKGROUND

Transcatheter aortic valve implantation (TAVI) has emerged as a promising treatment strategy for patients with severe symptomatic aortic stenosis (AS). Moreover, characteristics of Chinese patients that are different from those of patients in Western countries, such as a high prevalence of bicuspid aortic valve (BAV), severe calcification, and a small peripheral artery diameter, have been observed.

OBJECTIVE

A novel large medical balloon with ultra-high strength was fabricated through the blending modification of PA12/TR55.

METHODS

The mechanical properties, particularly puncture resistance, of large balloons were thoroughly studied, and TR55, a modified nylon pellet with good mechanical properties and excellent compatibility with PA12, was applied to modify PA12.

RESULTS

Compared with pure PA12, the fabricated PA12/TR55 balloon exhibited a higher bursting pressure, lower compliance, and higher punctures resistance while retaining good processability and excellent biocompatibility. The improved mechanical properties can be attributed to an increase in crystallinity and densification.

CONCLUSIONS

The PA12/TR55 balloon is suitable for Chinese patients with bicuspid aortic valve and severe calcification and therefore has potential for clinical application in transcatheter aortic valve implantation. Moreover, this blending modification provides a simple but efficient method of solving other problems in cardiac angioplasty or cryoablation in which mechanical reinforcement of balloons may be necessary.

The Negative Effect of Mean Perfusion Pressure on the Development of Acute Kidney Injury after Transcatheter Aortic Valve Implantation

Objective

To evaluate the predictive value of mean perfusion pressure (mPP) in the development of acute kidney injury (AKIN) after transcatheter aortic valve implantation (TAVI).

Methods

One hundred and forty seven consecutive patients with aortic stenosis (AS) were evaluated for this study and 133 of them were included. Mean arterial pressure (mAP) and central venous pressure (CVP) were used to calculate mPP before TAVI procedure (mPP = mAP-CVP). The occurrence of AKIN was evaluated with AKIN classification according to the Valve Academic Research Consortium-2 recommendations. The patients were divided into two groups according to the receiver operating characteristic (ROC) analysis of their mPP levels (high-risk group and low-risk group).

Results

The AKIN prevalence was 22.6% in this study population. Baseline serum creatinine level, glomerular filtration rate, amount of contrast medium, and the level of mPP were determined as predictive factors for the development of AKIN.

Conclusion

The occurrence of AKIN is associated with increased morbidity and mortality rates in patients with TAVI. In addition to the amount of contrast medium and basal kidney functions, our study showed that lower mPP was strongly associated with development of AKIN after TAVI.

Animal chronic total occlusion models: A review of the current literature and future goals

Coronary chronic total occlusions (CTOs) are commonly found in patients undergoing coronary angiography and is associated with poorer prognosis than in those patients with other forms of stable coronary artery disease. As such, with an increasing appreciation of this clinical entity, there is a need to identify, firstly the pathophysiological process driving its formation, as well as new percutaneous strategies for revascularisation with long term durability and improved outcomes. An appropriate, reliable and reproducible animal model is vital for both of these objectives. We review the prevalence of spontaneous collaterals in different species, as well as review the current literature with respect to animal models of CTOs, and compare and contrast the advantages and disadvantages of these differing models. Whilst both extrinsic compression models and endoluminal procedures may create situations analogous to a CTO in a human, the ideal animal model of a CTO will include an occluded artery, functional collaterals and a viable myocardium. This would allow study of the process driving collateral formation and arteriogenesis as well as percutaneous intervention strategies for both acute and long term benefits.

Temporal Trends and Clinical Consequences of Wait Times for Transcatheter Aortic Valve Replacement

Background:

Transcatheter aortic valve replacement (TAVR) represents a paradigm shift in the therapeutic options for patients with severe aortic stenosis. However, rapid and exponential growth in TAVR demand may overwhelm capacity, translating to inadequate access and prolonged wait times. Our objective was to evaluate temporal trends in TAVR wait times and the associated clinical consequences.

Methods:

In this population-based study in Ontario, Canada, we identified all TAVR referrals from April 1, 2010, to March 31, 2016. The primary outcome was the median total wait time from referral to procedure. Piecewise regression analyses were performed to assess temporal trends in TAVR wait times, before and after provincial reimbursement in September 2012. Clinical outcomes included all-cause death and heart failure hospitalizations while on the wait list.

Results:

The study cohort included 4461 referrals, of which 50% led to a TAVR, 39% were off-listed for other reasons, and 11% remained on the wait list at the conclusion of the study. For patients who underwent a TAVR, the estimated median wait time in the postreimbursement period stabilized at 80 days and has remained unchanged. The cumulative probability of wait-list mortality and heart failure hospitalization at 80 days was ≈2% and 12%, respectively, with a relatively constant increase in events with increased wait times.

Conclusions:

Postreimbursement wait time has remained unchanged for patients undergoing a TAVR procedure, suggesting the increase in capacity has kept pace with the increase in demand. The current wait time of almost 3 months is associated with important morbidity and mortality, suggesting a need for greater capacity and access.

Aortic Valve Predilatation with a Small Balloon, without Rapid Pacing, prior to Transfemoral Transcatheter Aortic Valve Replacement

Objectives

The aim of this study is to assess the feasibility and clinical outcome of transcatheter aortic valve replacement (TAVR) using aortic valve predilatation (AVPD) with a small, nonocclusive balloon.

Background

Balloon aortic valvuloplasty (BAV) under rapid pacing is generally performed in TAVR to ensure the passage and sufficient deployment of the prosthesis in the stenotic AV. BAV may cause serious complications, such as left ventricular stunning or cerebrovascular embolism.

Methods

A cohort of 50 consecutive patients with severe aortic stenosis underwent transfemoral TAVR with the Edwards Sapien 3-heart valve. All patients underwent AVPD with a small, nonocclusive balloon (12 × 60 or 14 × 60 mm) without rapid pacing. Procedural data and clinical outcomes were analyzed.

Results

The mean age of the cohort was 81 ± 6 years and the mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 13 ± 9. Crossing the AV and prosthesis implantation was successful in all cases. The postprocedural mean AV gradient was 12 ± 5 mmHg. There were no cases of aortic regurgitation ≥ grade 2. No periprocedural stroke occurred. One patient (2%) with chronic atrial fibrillation displayed a transient Wernicke aphasia occurring more than 24 hours after TAVR. Mortality was 0% at 30 days after procedure.

Conclusion

In TAVR, AVPD with a small, nonocclusive balloon can be safely performed. By avoiding rapid pacing, this technique may be a valid alternative to traditional BAV. Whether or not the use of APVD without rapid pacing translates into less periprocedural complications needs to be assessed in future studies.

Degenerative Mitral Stenosis: From Pathophysiology to Challenging Interventional Treatment

Mitral stenosis (MS) is characterized by obstruction of left ventricular inflow as a result of narrowing of the mitral valve orifice. Although its prevalence has declined over the last decade, especially in developed countries, it remains an important cause of morbidity and mortality.  The most often cause of MS worldwide is still postrheumatic mitral valve disease. However, in developed countries, degenerative or calcific changes cause MS in a siginificant proportion of patients. Although the range of treatment for mitral valve disease has grown over the years in parallel with transcatheter therapies for aortic valve disease, these improvements in mitral valve disease therapy have experienced slower development. This is mainly due to the more complex anatomy of the mitral valve and entire mitral apparatus, and the interplay of the mitral valve with the left ventricle which hinders the development of effective implantable mitral valve devices. This is especially the case with degenerative MS where percutaneous or surgical comissurotomy is rarely employed due to the presence of extensive annular calcification and at the base of leaflets, without associated commissural fusion. However, the last few years have witnessed innovations in transcatheter interventional procedures for degenerative MS which consequently hinted that in the future, transcatheter mitral valve replacement could be the treatment of choice for these patients.

Transcatheter aortic valve implantation using the ACURATE TA™ system: 1-year outcomes and comparison of 500 patients from the SAVI registries

OBJECTIVES: The ACURATE TA^TM system is a self-expanding transcatheter heart valve system designed for transapical access which has been proven to be safe and effective in the controlled setting of clinical trials. The SAVI-1 and SAVI-2 registries aimed to assess whether these promising outcomes can be translated into all-comers clinical routine.

METHODS: From November 2011 to 2012 (SAVI-1), and November 2013 to 2014 (SAVI-2), a total of 500 patients were enrolled in the prospective, all-comers, multicentre, multinational SAVI registries. Patients were treated according to the standard of care at their respective hospitals. We report and compare 30-day and 1-year clinical outcomes between SAVI-1 and -2.

RESULTS: Patients were 80.8 ± 6.1 years old, the mean logistic EuroSCORE-I was 23.4 ± 14.3%. Valves were deployed under rapid pacing in 71.3% of the procedures in SAVI-1, and in 3.6% in SAVI-2. There was no relevant difference in clinical and echocardiographic outcomes between SAVI-1 and SAVI-2. Overall mortality at 30 days and 1 year was 6.8% and 19.9%, the stroke rate was 2.2% and 3.7%, respectively; 10.2% of patients had received a permanent pacemaker, and no transcatheter valve-related complications after discharge were observed. Paravalvular leakage ≥2+ was reported in 1.9% of the patients at the early follow-up, and in 2.6% at the 1-year follow-up.

CONCLUSIONS: The SAVI-registries have confirmed that transapical implantation using the ACURATE TA^TM device is safe and effective in an all-comers setting with low complication rates and stable performance outcomes at short-term and 1 year; outcomes were similar between SAVI-1 and -2. ClinicalTrials.gov: NCT02663375

Outcomes in 937 Intermediate-Risk Patients Undergoing Surgical Aortic Valve Replacement in PARTNER-2A

BACKGROUND

The Placement of Aortic Transcatheter Valves 2A (PARTNER-2A) randomized trial compared outcomes of transfemoral transcatheter and surgical aortic valve replacement (SAVR) in intermediate-risk patients with severe aortic stenosis. The purpose of the present study was to perform an in-depth analysis of outcomes after SAVR in the PARTNER-2A trial.

METHODS

From January 2012 to January 2014, 937 patients underwent SAVR at 57 centers. Mean age was 82 ± 6.7 years and 55% were men. Less-invasive operations were performed in 140 patients (15%) and concomitant procedures in 198 patients (21%). Major outcomes and echocardiograms were adjudicated by an independent events committee. Follow-up was 94% complete to 2 years.

RESULTS

Operative mortality was 4.1% (n = 38, Society of Thoracic Surgeons predicted risk of mortality: 5.2% ± 2.3%), observed to expected ratio (O/E) was 0.8, and in-hospital stroke was 5.4% (n = 51), twice expected. Aortic clamp and bypass times were 75 ± 30 minutes and 104 ± 46 minutes, respectively. Patients having severe prosthesis-patient mismatch (n = 260, 33%) had similar survival to patients without (p > 0.9), as did patients undergoing less-invasive SAVR (p = 0.3). Risk factors for death included cachexia (p = 0.004), tricuspid regurgitation (p = 0.01), coronary artery disease (p = 0.02), preoperative atrial fibrillation (p = 0.001), higher white blood cell count (p < 0.0001), and lower hemoglobin (p = 0.0002).

CONCLUSIONS

In this adjudicated prospective study, SAVR in intermediate-risk patients had excellent results at 2 years. However, there were more in-hospital strokes than expected, most likely attributable to mandatory neurologic assessment after the procedure. No pronounced structural valve deterioration was found during 2-year follow-up. Continued long-term surveillance remains important.

The optimal shape of an aortic heart valve replacement – on the road to the consensus

The steady increase in the number of patients with diseased aortic valves demands the development of effective aortic valve replacement procedures. Engineering and technology offer various manufactured alternatives, but none can exactly match the natural human valve. In addition to the experts of heart valve tissue engineering, many researchers focus on specific aspects of the manufacturing of artificial valves. The aim of this study was to benefit such manufacturing processes. From the contributor's perspective, it is vital to gain comprehensive knowledge before embarking on this project. The perfect/optimal shape of the valve is the fundamental aspect that needs to be considered by all participants. It is noteworthy that the geometry not only limits the functionality of the structure but also determines the choice of material and engineering methods. In this study, we attempt to determine if current knowledge is sufficient to reach consensus on the issue of the optimum shape of the valve. Here, we not only provide a brief overview of traditional literature but also include the opinions of experts. This innovative way of scientific communication is unprecedented in scientific literature, and we hope that both professionals and contributors will find this study useful.

Transcatheter mitral valve implantation: a percutaneous transapical system

Objectives

Despite recent achievements, implantation of a transcatheter mitral valved stent remains challenging. In this study, we present a different approach for implantation of a percutaneous mitral valved stent.

Methods

Percutaneous transapical access is combined with, respectively, a left-transatrial, right-transatrial/transseptal or transfemoral/transseptal approach for mitral valve stent implantation and secure fixation. The apical fixation and occlusion are ensured with an Amplatzer occluder. This novel approach was tested in 22 porcine hearts in an in vitro setting under the guidance of fluoroscopy ( n  = 11) and endoscopy ( n  = 11). The in vitro setup included continuous flushing at 37 °C. We determined the feasibility, time of implantation, stent deployment and stent fixation.

Results

Percutaneous mitral valved stent implantation was successful in all cases. Good handling properties and precise positioning were achieved. Time of implantation was comparable in the fluoroscopic and endoscopic groups at 10:41 ± 3:18 and 10:09 ± 2:42 min, respectively. Apical fixation with the occluder was excellent in all 22 cases.

Conclusions

The feasibility of percutaneous mitral valved stent implantation has been demonstrated in preliminary in vitro experiments. Subsequent studies are warranted to determine the efficacy of this minimally invasive catheter-based mitral valved stent implantation.

Primary Mitral Valve Regurgitation Outcome in Patients With Severe Aortic Stenosis 1 Year After Transcatheter Aortic Valve Implantation: Echocardiographic Evaluation

BACKGROUND:

Mitral valve regurgitation (MR), present in up to 74% of the patients with severe aortic stenosis (AS), can be a negative prognostic factor when moderate or severe. The outcome of MR after percutaneous transcatheter aortic valve implantation (TAVI) and predictors associated with that outcome have not been well established in the literature.

OBJECTIVE:

To assess the outcome of primary MR in patients submitted to TAVI and to identify associated factors.

METHODS:

Observational study of patients with symptomatic severe AS submitted to TAVI from January 2009 to April 2015 at two specialized centers. Echocardiographic outcome was assessed with data collected before and 1 year after TAVI.

RESULTS:

Of the 91 patients with MR submitted to TAVI and followed up for at least 12 months, 67 (73.6%) had minimum/mild MR before the procedure and 24 (26.4%) had moderate/severe MR. Of those with minimum/mild MR, 62 (92.5%) had no change in the MR grade (p < 0.001), while 5 (7.5%) showed worsening. Of those with moderate/severe MR, 8 (33.3%) maintained the same grade and 16 (66.7%) improved it (p = 0.076). Patients with moderate/severe MR who improved MR grade had lower EuroSCORE II (p = 0.023) and STS morbidity (p = 0.027) scores, as compared to those who maintained the MR grade.

CONCLUSION:

MR grades change after TAVI. This study suggests a trend towards improvement in moderate/severe MR after TAVI, which was associated with lower preoperative risk scores.

FUNDAMENTOS:

A insuficiência valvar mitral (IM), presente em até 74% dos pacientes com estenose aórtica (EA) grave, pode representar um fator prognóstico negativo quando moderada ou importante. A evolução da IM após implante percutâneo de valva aórtica transcateter (TAVI) e preditores associados a essa evolução não estão bem estabelecidos na literatura.

OBJETIVOS:

Avaliar a evolução da IM primária em pacientes submetidos ao TAVI e identificar fatores associados a essa evolução.

MÉTODOS:

Realizou-se um estudo observacional em pacientes com EA grave sintomática, submetidos ao TAVI no período de janeiro de 2009 a abril de 2015 em dois centros especializados. Foram avaliados desfechos ecocardiográficos com dados antes e 1 ano após a intervenção.

RESULTADOS:

Dos 91 pacientes com IM que realizaram TAVI e tinham acompanhamento de pelo menos 12 meses, 67 (73,6%) apresentavam IM mínima ou discreta antes da realização do procedimento e 24 (26,4%), IM moderada ou grave. Entre os com IM mínima ou discreta, 62 (92,5%) não apresentaram mudança no grau de refluxo (p < 0,001) e 5 (7,5%) tiveram piora. Entre os com IM moderada ou grave, 8 (33,3%) permaneceram na mesma classe e 16 (66,7%) tiveram melhora (p = 0,076). Pacientes com IM moderada ou grave que melhoraram o grau de insuficiência apresentavam menores valores de EuroSCORE II (p = 0,023) e STS morbidade (p = 0,027), quando comparados aos que continuaram na mesma classe.

CONCLUSÃO:

Observou-se mudança significativa no grau de IM após realização de TAVI. Este estudo sugere uma tendência de melhora da IM moderada ou grave após TAVI, o que se associou a escores de risco pré-operatórios menos elevados.

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.

Preprocedural but not periprocedural high-sensitive Troponin T levels predict outcome in patients undergoing transcatheter aortic valve implantation

AIM

Risk assessment of patients undergoing transcatheter aortic valve implantation (TAVI) remains difficult. Biomarkers have been shown to provide potential prognostic information. Here, we aimed to analyze whether the biomarker high-sensitivity Troponin T (hsTNT) could be used to improve risk stratification.

METHOD

We prospectively enrolled 267 patients undergoing TAVI. Biomarkers (hsTNT and NTproBNP) were measured 1 day before, and 3 and 7 days postprocedure. All possible prognostic factors upon survival time were analyzed by Cox regression analysis.

RESULTS

A total of 259 patients (mean age 82±6.1 years) were available for complete follow-up. The median Logistic EuroSCORE (Log ES) and Log ES II were 21.16% (Q1=13.92; Q3=34.27) and 6.42% (Q1=3.89; Q3=11.07), respectively. Median follow-up was 290 (Q1=88; Q3=529) days. A total of 71 deaths occurred during follow-up, and the 30-day mortality was 5.8%. Median baseline hsTNT was 27.4 pg/mL (Q1=16.2; Q3=46 pg/mL). From all potential mortality-associated factors, only preprocedural hsTNT level (P=.001), elevated Log ES (P=.03) as well as acute kidney injury (P<.001) and chronic obstructive pulmonary disease (COPD) (P=.039) emerged as independent prognostic parameters for adverse outcome. We also tested whether the Valve Academic Research Consortium-2 (VARC-II) cutoff for myocardial damage (hsTNT peak value exceeding 15× the upper reference limit + at least 50% increase) was of prognostic relevance. At 72-hours post-TAVI, 36.2% of the patients matched these VARC-II criteria of myocardial damage. However, these patients did not display a difference in survival compared to patients without significant myocardial injury.

CONCLUSION

Elevated preprocedural hsTNT represents an independent risk predictor of all-cause death while periprocedural hsTNT elevation failed to show prognostic relevance.

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.

Transapical Cannulation Through a Transcatheter Aortic Valve Implantation Valve: A Novel Approach for Cardiogenic Collapse

We report a case of rescue bypass cannulation of the ventricular apex during a transapical transcatheter aortic valve implantation procedure in a patient with peripheral vascular disease not amenable to peripheral cannulation. Following rapid pacing and deployment of the transcatheter valve, cardiac function did not recover. The arterial cannula was inserted through the left ventricular apex, at the site of the transapical sheath, and advanced across the prosthetic valve, allowing for rapid initiation of cardiopulmonary bypass. The patient׳s ventricular function recovered promptly and cardiopulmonary bypass was weaned without difficulty.

Role of Imaging in Transcatheter Aortic Valve Replacement

OPINION STATEMENT

Transcatheter aortic valve replacement (TAVR) has emerged as an effective treatment alternative in patients with severe aortic stenosis (AS) who are deemed surgically high-risk or ineligible for surgery. Pre-procedural imaging, in particular computed tomography (CT), plays an integral part in the planning and performance of TAVR and is crucial for a successful treatment. Novel technological advances in CT include high-pitch, low kV acquisitions, and iterative reconstruction resulting in high image quality at substantially reduced scan duration, contrast volume, and radiation exposure. Given the high spatial and temporal resolution of the acquisitions, CT angiography provides critical information on the eligibility for the peripheral vascular access, aortic root assessment, as well as the aortic annulus measurements, including the coronary ostia and concomitant cardiac pathology. Pre-procedural CT imaging is key for appropriate device size selection to minimize peri-procedural complications and optimize procedural success. In this article, we review the current state of imaging in the pre-interventional setting of TAVR with a special emphasis on CT.