5-Year Outcomes After TAVR With Balloon-Expandable Versus Self-Expanding Valves: Results From the CHOICE Randomized Clinical Trial

Balloon-Expandable versus Self-Expandable Valves in Transcatheter Aortic Valve Implantation: Complications and Outcomes from a Large International Patient Cohort

Background: Both balloon-expandable (BE) and self-expandable (SE) valves for transcatheter aortic valve implantation (TAVI) are broadly used in clinical practice. However, adequately powered randomized controlled trials comparing these two valve designs are lacking. Methods: The CENTER-study included 12,381 patients undergoing transfemoral TAVI. Patients undergoing TAVI with a BE-valve (n = 4096) were compared to patients undergoing TAVI with an SE-valve (n = 4096) after propensity score matching. Clinical outcomes including one-year mortality and stroke rates were assessed. Results: In the matched population of n = 5410 patients, the mean age was 81 ± 3 years, 60% was female, and the STS-PROM predicted 30-day mortality was 6.2% (IQR 4.0–12.4). One-year mortality was not different between patients treated with BE- or SE-valves (BE: 16.4% vs. SE: 17.0%, Relative Risk 1.04, 95%CI 0.02–1.21, p = 0.57). One-year stroke rates were also comparable (BE: 4.9% vs. SE: 5.3%, RR 1.09, 95%CI 0.86–1.37, p = 0.48). Conclusion: This study suggests that one-year mortality and stroke rates were comparable in patients with severe aortic valve stenosis undergoing TAVI with either BE or SE-valves.

Aortic valve reintervention in patients with failing transcatheter aortic bioprostheses: A statewide experience

BACKGROUND

Despite the rapid adoption of transcatheter aortic valve replacement since its approval, the frequency and outcomes of aortic valve reintervention after transcatheter aortic valve replacement are poorly understood.

METHODS

Valve reinterventions, either surgical transcatheter aortic valve replacement valve explantation or repeat transcatheter aortic valve replacement, between 2012 and 2019 were queried using the Society of Thoracic Surgeons Database and the Transcatheter Valve Therapy Registry through the Michigan Statewide quality collaborative. The reintervention frequency and clinical outcomes including observed-to-expected mortality ratio using Society of Thoracic Surgeons Predicted Risk of Mortality were reviewed.

RESULTS

Among 9694 transcatheter aortic valve replacement recipients, a total of 87 patients (0.90%) received a reintervention, consisting of 34 transcatheter aortic valve replacement explants and 53 repeat transcatheter aortic valve replacement procedures. The transcatheter aortic valve replacement explant group demonstrated a higher Society of Thoracic Surgeons Predicted Risk of Mortality. Reintervention cases increased from 0 in 2012 and 2013 to 26 in 2019. The proportion of transcatheter aortic valve replacement explants among all reinterventions increased and was 65% in 2019. Self-expandable devices had a higher reintervention rate than balloon-expandable devices secondary to a higher transcatheter aortic valve replacement explant frequency (0.58% [23/3957] vs 0.19% [11/5737]; P = .001), whereas repeat transcatheter aortic valve replacement rates were similar (0.61% [24/3957] vs 0.51% [29/5737]; P = .51). Among patients with transcatheter aortic valve replacement explants, contraindications to repeat transcatheter aortic valve replacement included unfavorable anatomy (75%), need for other cardiac surgery (29%), other structural issues by transcatheter aortic valve replacement device (18%), and endocarditis (12%). For transcatheter aortic valve replacement explant and repeat transcatheter aortic valve replacement, the 30-day mortality was 15% and 2% (P = .032) and the observed-to-expected mortality ratio was 1.8 and 0.3 (P = .018), respectively.

CONCLUSIONS

Aortic valve reintervention remains rare but is increasing. The clinical impact of transcatheter aortic valve replacement explant was substantial, and the proportion of transcatheter aortic valve replacement explants was significantly higher in patients with a self-expandable device.

TAVI Beyond 3 Years: Durability and Predictors for Survival

The use of transcatheter aortic valve implantation (TAVI) has greatly increased over the past 2 decades and now has overtaken surgical aortic valve replacement. We have limited data regarding the long-term durability of TAVI and the predictors of survival. Calcification, inflammation, fibrous tissue deposition, and mechanical stress are important in the structural deterioration of surgical bioprosthetic valves and likely contribute to TAVI durability. However, TAVI has several differences to surgical valve replacement such as valve preparation, valve to native anatomy interaction, and valve sizing which all likely contribute to durability and long-term survival. Most procedures have been performed on older patients and therefore long-term follow-up studies have noted mortality of approximately 50% at 5 years and 75% by 7 years. Current data are limited by the high mortality of patients who have received TAVI often as a result of age, frailty, and other competing comorbidities. TAVI as compared with surgical valve replacement is associated with several differences including higher conduction abnormalities (i.e., need for pacemakers) and paravalvular leak, both of which may affect long-term morbidity and mortality. In this review, we discuss the current status of our knowledge and identify areas that require further investigation.

Transcatheter Aortic Valve Replacement for Degenerated Transcatheter Aortic Valves: The TRANSIT International Project

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Clinical and Technical Challenges of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Implantation

Prosthesis-patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Predictors and Clinical Impact of Prosthesis-Patient Mismatch After Self-Expandable TAVR in Small Annuli

OBJECTIVES

The aim of this study was to define predictors of prosthesis-patient mismatch (PPM) and its impact on mortality after transcatheter aortic valve replacement (TAVR) with self-expandable valves (SEVs) in patients with small annuli.

BACKGROUND

TAVR seems to reduce the risk for PPM compared with surgical aortic valve replacement, especially in patients with small aortic annuli. Nevertheless, predictors and impact of PPM in this population have not been clarified yet.

METHODS

Predictors of PPM and all-cause mortality were investigated using multivariable logistic regression analysis from the cohort of the TAVI-SMALL (International Multicenter Registry to Evaluate the Performance of Self-Expandable Valves in Small Aortic Annuli) registry, which included patients with severe aortic stenosis and small annuli (annular perimeter <72 mm or area <400 mm² on computed tomography) treated with transcatheter SEVs: 445 patients with (n = 129) and without (n = 316) PPM were enrolled.

RESULTS

Intra-annular valves conferred increased risk for PPM (odds ratio [OR]: 2.36; 95% confidence interval [CI]: 1.16 to 4.81), while post-dilation (OR: 0.46; 95% CI: 0.25-0.84) and valve oversizing (OR: 0.53; 95% CI: 0.28-1.00) seemed to protect against PPM occurrence. At a median follow-up of 354 days, patients with severe PPM, but not those with moderate PPM, had a higher all-cause mortality rate compared with those without PPM (log-rank p = 0.008). Multivariable Cox regression confirmed severe PPM as an independent predictor of all-cause mortality (hazard ratio: 4.27; 95% CI: 1.34 to 13.6).

CONCLUSIONS

Among patients with aortic stenosis and small aortic annuli undergoing transcatheter SEV implantation, use of intra-annular valves yielded higher risk for PPM; conversely, post-dilation and valve oversizing protected against PPM occurrence. Severe PPM was independently associated with all-cause mortality.

Aortic valve replacement vs. balloon-expandable and self-expandable transcatheter implantation: A network meta-analysis

INTRODUCTION

Recently, observational data have raised concerns about safety of selfexpandable (SE) compared to balloon-expandable (BE) valves in TAVI, although potentially limited by patient selection bias.

METHODS

All Randomized Controlled Trials (RCTs) comparing BE vs. SE TAVI or/and vs. aortic valve replacement (AVR) were included and compared through Network Meta Analysis (NMA). All-cause and cardiovascular (CV) mortality were the primary endpoints, stroke, rates of permanent pacemaker implantation (PPI), moderate/severe paravalvular leak (PVL) and reintervention were the secondary endpoints. Results We obtained data from 11 RCTs, encompassing 9752 patients. After one and two years, no significant differences for allcause and CV mortality were observed. Compared to surgical bioprostheses, both BE and SE TAVI reduced the risk of acute kidney injury (OR 0.42; CI 95% 0.30-0.60 and OR 0.44; CI 95% 0.32-0.60), new-onset atrial fibrillation (OR 0.24; CI 95% 0.14-0.42 and OR 0.21; CI 95% 0.13-0.34) and major bleedings (OR 0.32; CI 95% 0.16-0.65 and OR 0.47; CI 95% 0.25-0.89). The BE prostheses reduced the risk of moderate/severe PVL at 30-day (OR 0.31; CI 95% 0.17-0.55) and of PPI both at 30-day (OR 0.51; CI 95% 0.33-0.79) and 1 year (OR 0.40; CI 95% 0.30-0.55) as compared to SE TAVI. Conclusions A TAVI strategy, independently from BE or SE prostheses, offers a midterm survival comparable to AVR. The BE prostheses are associated with a reduction of PPI and PVL compared to SE prostheses without any differences in all-cause and CV mortality during two years of follow up. PROSPERO ID CRD42020182407.

Current Therapeutic Options in Aortic Stenosis

Aortic stenosis is the most common valvular disease requiring valve replacement. Valve replacement therapies have undergone progressive evolution since the 1960s. Over the last 20 years, transcatheter aortic valve replacement has radically transformed the care of aortic stenosis, such that it is now the treatment of choice for many, particularly elderly, patients. This review provides an overview of the pathophysiology, presentation, diagnosis, indications for intervention, and current therapeutic options for aortic stenosis.

Neurocognitive Status after Aortic Valve Replacement: Differences between TAVI and Surgery

Over the past decade, indications for transcatheter aortic valve implantation (TAVI) have progressed rapidly—procedural numbers now exceed those of surgical aortic valve replacement (SAVR) in many countries, and TAVI is now a realistic and attractive alternative to SAVR in low-risk patients. Neurocognitive outcomes after TAVI and SAVR remain an issue and sit firmly under the spotlight as TAVI moves into low-risk cohorts. Cognitive decline and stroke carry a significant burden and predict future functional decline, reduced mobility, poor quality of life and increased mortality. Early TAVI trials used varying neurocognitive definitions, and outcomes differed significantly as a result. Recent international consensus statements defining endpoints following TAVI and SAVR have standardised neurological outcomes and facilitate interpretation and comparison between trials. The latest TAVI and SAVR trials have demonstrated more consistent and favourable neurocognitive outcomes for TAVI patients, and cerebral embolic protection devices offer the prospect of further refinement and improvement.

Long-term outcomes of self-expanding versus balloon-expandable transcatheter aortic valves: Insights from the OBSERVANT study

OBJECTIVES

To compare clinical outcomes of balloon-expandable (BE) and self-expanding (SE) transcatheter aortic valves (TAVs) up to 5 years.

BACKGROUND

To date, no robust, comparative data of BE and SE TAVs at long-term are available.

METHODS

We considered a total of 1,440 patients enrolled in the multicenter OBSERVANT study and undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI) with either supra-annular SE (n = 830, 57.6%) and intra-annular BE (n = 610, 42.4%) valves. Clinical outcomes of the two groups were compared after adjustment using inverse probability of treatment weighting (IPTW) and confirmed by sensitivity analysis with propensity score matching.

RESULTS

Patients receiving SE valve showed a higher all-cause mortality at 5 years (Kaplan-Meier estimates 52.3% vs. 47.7%; Hazard ratio [HR] 1.18, 95% confidence interval [CI] 1.01-1.38, p = .04). Landmark analyses showed that there was a not statistically significant reversal of risk excess against the BE group starting from 3 years after TAVI (3-5 years HR 0.97, 95% CI 0.76-1.25, p = .86). Post-procedural, moderate/severe paravalvular regurgitation (PVR)(HR 1.46, 95% CI 1.14-1.87; p < .01) and acute kidney injury (AKI)(HR 3.89, 95% CI 2.47-6.38; p < .01) showed to be independent predictors of 5-year all-cause mortality in multivariable analysis.

CONCLUSIONS

Considering the intrinsic limitations of the OBSERVANT study, we found that patients undergoing TF-TAVI with a supra-annular SE valve had a higher all-cause mortality compared to those receiving an intra-annular BE valve at 5 years. A late catch up phenomenon of patients receiving the BE valve was observed beyond 3 years. Post-procedural moderate/severe PVR seems to play a crucial role in determining this finding. Comparative studies of new generation devices with longer follow-up are needed to evaluate the benefit of each specific TAV type.

The current diagnosis and treatment of patients with aortic valve stenosis

Aortic valve stenosis (AS) is the third most frequent cardiovascular abnormality after coronary artery disease and hypertension. A bicuspid aortic valve is the most common cause for AS until seventh decade and calcific valve degeneration is responsible thereafter. In symptomatic patients, The risk of death increases from ≤1%/year to 2%/month. An echo valve area ≤1 cm², peak transaortic velocity ≥4 m/s, mean valve gradient ≥40 mmHg and/or computerized tomography valve calcium score >2000 Agatston units (AU) for males or more than 1200 AU for females indicate severe AS. AS stages and management are discussed. Valve replacement is based on surgical risk, valve durability/hemodynamics, need for anticoagulation and patient preferences. EuroSCORE ≥20%, Society of Thoracic Surgeons Predicted Risk of Mortality ≥8% and co-morbidities indicate high surgical risk. Surgery is recommended for low-intermediate risk patients. Transcatheter aortic valve implantation is an alternative in older patients at low, intermediate, high or prohibitive risk. Transaortic valve implantation/replacement trials are summarized.

Three-Year Survival after Transcatheter Aortic Valve Replacement: Findings from the Marshfield Aortic Valve Experience (MAVE) Study

Background: Transcatheter aortic valve replacement (TAVR) is a rapidly evolving treatment for severe aortic stenosis. However, uncertainties exist for optimal valve selection as there are few long-term studies comparing patient survival by valve type.Objective: We hypothesized that self-expandable valves (SEV) would provide a survival advantage over balloon expandable valves (BEV), as SEV continue to expand and might better accommodate to the anatomy of the aortic valve over time.Methods: We examined outcomes according to valve type from a rural tertiary referral center between 2012 and 2017.Results: Out of 269 patients, 77 deaths (28.6%) occurred over the study period with 6 deaths by 1 month post-TAVR and 37 deaths by 1 year post-TAVR. The median observation time for survivors was 21.5 months. The probability of survival at 3 years was 60.7% and 61.9% for patients who underwent treatment with SEV and BEV, respectively. There was no statistically significant difference in overall patient survival with or without adjustment for factors such as age, sex, race, and aortic valve area. Additionally, in a secondary analysis restricted to those patients treated in later years (2015-2017) survival among patients with BEV appeared superior (HR=0.456, P=0.015).Conclusion: Patients who underwent TAVR at a rural medical center with SEV showed similar survival compared to those who received a BEV. Superior survival was observed among those who received BEV versus SEV between 2015 and 2017.

Rationale and design of a randomized clinical trial comparing safety and efficacy of myval transcatheter heart valve versus contemporary transcatheter heart valves in patients with severe symptomatic aortic valve stenosis: The LANDMARK trial

BACKGROUND

The recent approval of transcatheter aortic valve replacement (TAVR) in patients with low operative risk has paved the way for the introduction of novel and potentially improved technologies. The safety and efficacy of these novel technologies should be investigated in randomized control trials against the contemporary TAVR devices. The objective of the LANDMARK trial is to compare the balloon-expandable Myval transcatheter heart valve (THV) series with contemporary THV (SAPIEN THV and Evolut THV series) series in patients with severe symptomatic native aortic stenosis.

METHODS/DESIGN

The LANDMARK trial (ClinicalTrials.govNCT04275726, EudraCT number 2020-000,137-40) is a prospective, randomized, multinational, multicenter, open-label, and noninferiority trial of approximately 768 patients treated with TAVR via the transfemoral approach. Patients will be allocated in a 1:1 randomization to Myval THV series (n = 384) or to contemporary THV (n = 384) (either of SAPIEN THV or Evolut THV series). The primary combined safety and efficacy endpoint is a composite of all-cause mortality, all stroke (disabling and nondisabling), bleeding (life-threatening or disabling), acute kidney injury (stage 2 or 3), major vascular complications, prosthetic valve regurgitation (moderate or severe), and conduction system disturbances (requiring new permanent pacemaker implantation), according to the Valve Academic Research Consortium-2 criteria at 30-day follow-up. All patients will have follow-up to 10 years following TAVR.

SUMMARY

The LANDMARK trial is the first randomized head-to-head trial comparing Myval THV series to commercially available THVs in patients indicated for TAVR. We review prior data on head-to-head comparisons of TAVR devices and describe the rationale and design of the LANDMARK trial.

Allegra Transcatheter Heart Valve inside a Degenerated Sutureless Aortic Bioprosthesis

Transcatheter aortic valve-in-valve implantation (VIV) is increasingly being used to successfully treat degenerated surgical aortic valve bioprostheses (SAVs). The new self-expanding transcatheter heart valve Allegra, from New Valve Technology with its special implantation mechanism, has proven its safety and feasibility for patients with degenerated SAVs, but it has never been used in the latest-generation sutureless SAV. To the best of our knowledge, this is the first description of the successful VIV of the Allegra prosthesis into a degenerated sutureless SAV, and the procedure yielded an excellent postinterventional hemodynamic results.

Comparison of Self-Expanding Bioprostheses for Transcatheter Aortic Valve Replacement in Patients With Symptomatic Severe Aortic Stenosis

Background:

Few randomized trials have compared bioprostheses for transcatheter aortic valve replacement, and no trials have compared bioprostheses with supra-annular design. The SCOPE 2 trial (Safety and Efficacy Comparison of Two TAVI Systems in a Prospective Randomized Evaluation 2) was designed to compare the clinical outcomes of the ACURATE neo and CoreValve Evolut bioprostheses for transcatheter aortic valve replacement.

Methods:

SCOPE 2 was a randomized trial performed at 23 centers in 6 countries between April 2017 and April 2019. Patients ≥75 years old with an indication for transfemoral transcatheter aortic valve replacement as agreed by the heart team were randomly assigned to receive treatment with either the ACURATE neo (n=398) or the CoreValve Evolut bioprostheses (n=398). The primary end point, powered for noninferiority of the ACURATE neo bioprosthesis, was all-cause death or stroke at 1 year. The key secondary end point, powered for superiority of the ACURATE neo bioprosthesis, was new permanent pacemaker implantation at 30 days.

Results:

Among 796 randomized patients (mean age, 83.2±4.3 years; mean Society of Thoracic Surgeons Predicted Risk of Mortality score, 4.6±2.9%), clinical follow-up information was available for 778 (98%) patients. Within 1 year, the primary end point occurred in 15.8% of patients in the ACURATE neo group and in 13.9% of patients in the CoreValve Evolut group (absolute risk difference, 1.8%, upper 1-sided 95% confidence limit, 6.1%; P =0.0549 for noninferiority). The 30-day rates of new permanent pacemaker implantation were 10.5% in the ACURATE neo group and 18.0% in the CoreValve Evolut group (absolute risk difference, –7.5% [95% CI, –12.4 to –2.60]; P =0.0027). No significant differences were observed in the components of the primary end point. Cardiac death at 30 days (2.8% versus 0.8%; P =0.03) and 1 year (8.4% versus 3.9%; P =0.01), and moderate or severe aortic regurgitation at 30 days (10% versus 3%; P =0.002) were significantly increased in the ACURATE neo group.

Conclusions:

Transfemoral transcatheter aortic valve replacement with the self-expanding ACURATE neo did not meet noninferiority compared with the self-expanding CoreValve Evolut in terms of all-cause death or stroke at 1 year, and it was associated with a lower incidence of new permanent pacemaker implantation. In secondary analyses, the ACURATE neo was associated with more moderate or severe aortic regurgitation at 30 days and cardiac death at 30 days and 1 year.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03192813.

Smart materials in cardiovascular implants: Shape memory alloys and shape memory polymers

Smart materials have intrinsic properties that change in a controlled fashion in response to external stimuli. Currently, the only smart materials with a significant clinical impact in cardiovascular implant design are shape memory alloys, particularly Nitinol. Recent prodigious progress in material science has resulted in the development of sophisticated shape memory polymers. In this article, we have reviewed the literature and outline the characteristics, advantages, and disadvantages of shape memory alloys and shape memory polymers which are relevant to clinical cardiovascular applications, and describe the potential of these smart materials for applications in coronary stents and transcatheter valves.

Degeneration of Bioprosthetic Heart Valves: Update 2020

The implantation of bioprosthetic heart valves (BHVs) is increasingly becoming the treatment of choice in patients requiring heart valve replacement surgery. Unlike mechanical heart valves, BHVs are less thrombogenic and exhibit superior hemodynamic properties. However, BHVs are prone to structural valve degeneration (SVD), an unavoidable condition limiting graft durability. Mechanisms underlying SVD are incompletely understood, and early concepts suggesting the purely degenerative nature of this process are now considered oversimplified. Recent studies implicate the host immune response as a major modality of SVD pathogenesis, manifested by a combination of processes phenocopying the long‐term transplant rejection, atherosclerosis, and calcification of native aortic valves. In this review, we summarize and critically analyze relevant studies on (1) SVD triggers and pathogenesis, (2) current approaches to protect BHVs from calcification, (3) obtaining low immunogenic BHV tissue from genetically modified animals, and (4) potential strategies for SVD prevention in the clinical setting.