Asymptomatic severe aortic stenosis, bicuspid aortic valves and moderate aortic stenosis in heart failure: New indications for transcatheter aortic valve implantation

Aortic stenosis (AS) remains one of the most common valvular heart diseases, with enormous impact on patient survival. Over the past years, transcatheter aortic valve implantation (TAVI) has become a reality worldwide, offering a less invasive method to treat AS. Apart from the classical indications for aortic valve disease, recent studies tried to address unanswered questions for TAVI - asymptomatic severe AS, bicuspid aortic valves and moderate AS in patients with heart failure. This review discusses the rationale of those possible indications, pitfalls and current evidence in the medical literature.

Long-term outcomes after transcatheter aortic valve implantation in failed bioprosthetic valves

Aims

Due to bioprosthetic valve degeneration, aortic valve-in-valve (ViV) procedures are increasingly performed. There are no data on long-term outcomes after aortic ViV. Our aim was to perform a large-scale assessment of long-term survival and reintervention after aortic ViV.

Methods and results

A total of 1006 aortic ViV procedures performed more than 5 years ago [mean age 77.7 ± 9.7 years; 58.8% male; median STS-PROM score 7.3% (4.2–12.0)] were included in the analysis. Patients were treated with Medtronic self-expandable valves (CoreValve/Evolut, Medtronic Inc., Minneapolis, MN, USA) (n = 523, 52.0%), Edwards balloon-expandable valves (EBEV, SAPIEN/SAPIEN XT/SAPIEN 3, Edwards Lifesciences, Irvine, CA, USA) (n = 435, 43.2%), and other devices (n = 48, 4.8%). Survival was lower at 8 years in patients with small-failed bioprostheses [internal diameter (ID) ≤ 20 mm] compared with those with large-failed bioprostheses (ID > 20 mm) (33.2% vs. 40.5%, P = 0.01). Independent correlates for mortality included smaller-failed bioprosthetic valves [hazard ratio (HR) 1.07 (95% confidence interval (CI) 1.02–1.13)], age [HR 1.21 (95% CI 1.01–1.45)], and non-transfemoral access [HR 1.43 (95% CI 1.11–1.84)]. There were 40 reinterventions after ViV. Independent correlates for all-cause reintervention included pre-existing severe prosthesis–patient mismatch [subhazard ratio (SHR) 4.34 (95% CI 1.31–14.39)], device malposition [SHR 3.75 (95% CI 1.36–10.35)], EBEV [SHR 3.34 (95% CI 1.26–8.85)], and age [SHR 0.59 (95% CI 0.44–0.78)].

Conclusions

The size of the original failed valve may influence long-term mortality, and the type of the transcatheter valve may influence the need for reintervention after aortic ViV.

Hemodynamic and Imaging Assessment of Transcatheter Aortic Valve Replacement with the Inovare® Proseal using Multislice Computed Tomography

Objective

To evaluate the hemodynamic performance (i.e., gradients and paravalvular leakage [PVL]) of the new and experimental Braile Inovare^® Proseal. Additionally, we aimed to assess pre and postoperatively the aortic annulus and the transcatheter prosthesis using multislice computed tomography (MSCT).

Methods

Patients were selected by a multidisciplinary heart team and referred for transcatheter aortic valve replacement (TAVR). MSCT was performed before and after surgery. Measurements of the aortic valve and prosthesis were conducted and correlated with the valve gradient and residual PVL.

Results

Twenty-one patients were selected for the protocol. Patients had a mean age of 79 years and 38% of them were of female sex. The mean EuroSCORE II value was 12.5%±10.8. Mean gradient was reduced from 45.8±11.04 mmHg to 5.59±2.61 mmHg and there were no instances of PVL worse than mild. There were no cases of coronary obstruction or procedural death. Circularity was present in all prostheses evaluated. Circularity indexes for the prostheses were: inflow 0.05±0.03, middle third 0.04±0.02, and outflow 0.04±0.02 (P=0.08). The mean distance between the prosthesis and the left and right coronary ostia were 14.8 mm±3.3 and 17.3 mm±3, respectively. Oversizing was appropriate with a mean of 22.14%±6%.

Conclusion

Braile Inovare^® Proseal transcatheter device has demonstrated low gradients with low rates of PVL. Oversizing by annular measurements was adequate. MSCT was adequate to evaluate device sizing and has demonstrated preserved expansibility and circularity in the evaluated cases.

First-in-Human Endo-Bentall Procedure for Simultaneous Treatment of the Ascending Aorta and Aortic Valve

We describe the endovascular management of a middle-aged woman who developed a bleeding suprasternal fistula after conventional aortic valve replacement. The patient's condition was considered inoperable. A customized stent attached to a transcatheter valve was successfully used to treat the individual, this being the first-in-human case of the promising Endo-Bentall procedure. (Level of Difficulty: Advanced.).

From bench to bedside: in vitro and in vivo evaluation of a neonate-focused nebulized surfactant delivery strategy

Background

Non-invasive delivery of nebulized surfactant has been a neonatology long-pursued goal. Nevertheless, the clinical efficacy of nebulized surfactant remains inconclusive, in part, due to the great technical challenges of depositing nebulized drugs in the lungs of preterm infants. The aim of this study was to investigate the feasibility of delivering nebulized surfactant (poractant alfa) in vitro and in vivo with an adapted, neonate-tailored aerosol delivery strategy.

Methods

Particle size distribution of undiluted poractant alfa aerosols generated by a customized eFlow-Neos nebulizer system was determined by laser diffraction. The theoretical nebulized surfactant lung dose was estimated in vitro in a clinical setting replica including a neonatal continuous positive airway pressure (CPAP) circuit, a cast of the upper airways of a preterm neonate, and a breath simulator programmed with the tidal breathing pattern of an infant with mild respiratory distress syndrome (RDS). A dose-response study with nebulized surfactant covering the 100–600 mg/kg nominal dose-range was conducted in RDS-modelling, lung-lavaged spontaneously-breathing rabbits managed with nasal CPAP. The effects of nebulized poractant alfa on arterial gas exchange and lung mechanics were assessed. Exogenous alveolar disaturated-phosphatidylcholine (DSPC) in the lungs was measured as a proxy of surfactant deposition efficacy.

Results

Laser diffraction studies demonstrated suitable aerosol characteristics for inhalation (mass median diameter, MMD = 3 μm). The mean surfactant lung dose determined in vitro was 13.7% ± 4.0 of the 200 mg/kg nominal dose. Nebulized surfactant delivered to spontaneously-breathing rabbits during nasal CPAP significantly improved arterial oxygenation compared to animals receiving CPAP only. Particularly, the groups of animals treated with 200 mg/kg and 400 mg/kg of nebulized poractant alfa achieved an equivalent pulmonary response in terms of oxygenation and lung mechanics as the group of animals treated with instilled surfactant (200 mg/kg).

Conclusions

The customized eFlow-Neos vibrating-membrane nebulizer system efficiently generated respirable aerosols of undiluted poractant alfa. Nebulized surfactant delivered at doses of 200 mg/kg and 400 mg/kg elicited a pulmonary response equivalent to that observed after treatment with an intratracheal surfactant bolus of 200 mg/kg. This bench-characterized nebulized surfactant delivery strategy is now under evaluation in Phase II clinical trial (EUDRACT No.:2016–004547-36).

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1096-9) contains supplementary material, which is available to authorized users.

Tracking the origin and dispersal of the Asian chestnut gall wasp Dryocosmus kuriphilus Yasumatsu (Hymenoptera, Cynipidae) in Europe with molecular markers

The Asian chestnut gall wasp, Dryocosmus kuriphilus, is an invasive pest causing significant damage to chestnut trees (Castanea spp., Fagaceae). Originating from China, it has recently invaded a wide range of regions in Europe and North America. Understanding the population genetic structure of important invasive pests is very useful for improving the knowledge concerning routes of expansion and colonizing capacity. Despite its economic importance, limited attention has been given to D. kuriphilus origin and spread, or to its genetic structure. In this study, D. kuriphilus populations sampled in eight European countries were screened using both mitochondrial (cytochrome c oxidase subunit 1; COI) and nuclear (internal transcribed spacer 2; ITS2) sequences, and Amplified Fragment Length Polymorphism (AFLP) markers. The molecular markers COI and ITS2 highlighted the presence of a single haplotype in all the studied populations. The recorded mitochondrial haplotype was identical to one of the most widespread haplotypes occurring in the native area (China). AFLP results indicated that D. kuriphilus individuals belong to two genetically distinct clusters without any further geographic clustering. These results suggest that D. kuriphilus populations in Europe could be the result of a single introduction of a Chinese founder population characterized by two genetically distinct lineages that subsequently spread rapidly across Europe. However, the possibility that populations originated from multiple introductions of the same Chinese mitochondrial haplotype cannot be excluded. The reported results provide useful information concerning this invasive species, potentially facilitating integrated pest management.

Transcatheter aortic valve replacement in failed surgical valves

Aortic valve-in-valve is a less invasive alternative to surgical redo in the treatment of failed bioprosthetic valves. While only inoperable patients underwent the procedure before, operators currently offer it to those at lower risk and worldwide experience is in the thousands. Early mortality has diminished in recent analyses and improvements in symptoms and quality of life have been documented. Main considerations with aortic valve-in-valve include elevated postprocedural gradients, coronary obstruction and leaflet thrombosis. Risk factors for each of these adverse events have been described at length. Aortic valve-in-valve offers a safe and effective option in the management of failed bioprosthetic valves.

Usefulness of Transcatheter Aortic Valve Implantation for Treatment of Pure Native Aortic Valve Regurgitation

Patients with pure native aortic valve regurgitation (NAVR) and increased surgical risk are often denied surgery. This retrospective study aimed to evaluate the "off-label" use of transcatheter heart valves (THV) for the treatment of NAVR. A total of 254 high surgical risk patients with NAVR (age 74 ± 12 years, Society of Thoracic Surgeons risk score 6.6 ± 6.2%) underwent transcatheter aortic valve implantation (TAVI) with early generation (43%) or newer generation (57%) devices at 46 different sites. Device success was significantly higher in patients treated with newer as compared with early generation THV (82% vs 47%, p <0.001). The difference was driven by lower rates of device malpositioning (9% vs 33%) and aortic regurgitation (AR) ≥ moderate (4% vs 31%) and translated into higher clinical efficacy at 30 days in patients treated with newer as compared with early generation THV (72% vs 56%, p = 0.041). Both THV under- and oversizing were associated with an increased risk of THV malpositioning. In conclusion, TAVI is a feasible treatment strategy in selected high-risk patients with NAVR but is associated with a considerable risk of THV malpositioning and residual AR. Although newer-generation THV are associated with better outcomes, novel devices for the treatment of NAVR are warranted.

Mortality prediction after transcatheter treatment of failed bioprosthetic aortic valves utilizing various international scoring systems: Insights from the Valve-in-Valve International Data (VIVID)

BACKGROUND

Transcatheter Aortic Valve Implantation (TAVI) is commonly used to deploy new bioprosthetic valves inside degenerated surgically implanted aortic valves in high risk patients. The three scoring systems used to assess risk of postprocedural mortality are: Logistic EuroSCORE (LES), EuroSCORE II (ES II), and Society of Thoracic Surgeons (STS).

OBJECTIVE

The purpose of this study is to analyze the accuracy of LES, ES II, and STS in estimating all-cause mortality after transcatheter aortic valve-in-valve (ViV) implantations, which was not assessed before.

METHODS

Using the Valve-in-Valve International Data (VIVID) registry, a total of 1,550 patients from 110 centers were included. The study compared the observed 30-day overall mortality vs. the respective predicted mortalities calculated by risk scores. The accuracy of prediction models was assessed based on calibration and discrimination.

RESULTS

Observed mortality at 30 days was 5.3%, while average expected mortalities by LES, ES II and STS were 29.49 (± 17.2), 14.59 (± 8.6), and 9.61 (± 8.51), respectively. All three risk scores overestimated 30-day mortality with ratios of 0.176 (95% CI 0.138-0.214), 0.342 (95% CI 0.264-0.419), and 0.536 (95% CI 0.421-0.651), respectively. 30-day mortality ROC curves demonstrated that ES II had the largest AUC at 0.722, followed by STS at 0.704, and LES at 0.698.

CONCLUSIONS

All three scores overestimated mortality at 30 days with ES II showing the highest predictability compared to LES and STS; and therefore, should be recommended for ViV procedures. There is a need for a dedicated scoring system for patients undergoing ViV interventions.

Matched comparison of next- and early-generation balloon-expandable transcatheter heart valve implantations in failed surgical aortic bioprostheses

AIMS

Transcatheter valve-in-valve implantation (VinV) is established for the treatment of degenerated surgical bioprostheses in patients at high operative risk. Our aim was to report on the first large assessment of VinV with next-generation balloon-expandable transcatheter heart valves.

METHODS AND RESULTS

After SAPIEN XT or SAPIEN 3 VinV, 514 patients were analysed using an inverse probability of treatment weighting. Standardised clinical and haemodynamic outcomes were compared, and core laboratory evaluation of implantation depth was performed. Thirty-day all-cause mortality was 0.6% and 3.5% for SAPIEN 3 and SAPIEN XT (p=0.077). Residual transprosthetic gradient ≥20 mmHg was observed in 38.3% (SAPIEN 3) and 35.7% (SAPIEN XT) of patients (p=0.627) with increased rates in small bioprostheses (≤21 mm true ID). In SAPIEN 3 VinV, low implantation depth >20% THV stent frame length was associated with a higher rate of elevated transaortic gradients (p=0.048). Similarly, an implantation depth >5 mm was linked to more pacemaker implantations (p=0.01). Overall, a trend towards higher pacemaker implantation rates was observed after SAPIEN 3 VinV (6% vs. 2.5% in SAPIEN XT, p=0.071).

CONCLUSIONS

Transcatheter aortic VinV with the balloon-expandable SAPIEN XT or SAPIEN 3 was similarly safe and effective. However, residual stenosis remains a concern, particularly in smaller bioprostheses and with increasing implantation depth.

Optimising the Haemodynamics of Aortic Valve-in-valve Procedures

Bioprosthetic surgical valves are increasingly implanted during cardiac surgery, instead of mechanical valves. These tissue valves are associated with limited durability and as a result transcatheter valve-in-valve procedures are performed to treat failed bioprostheses. A relatively common adverse event of aortic valve-in-valve procedures is residual stenosis. Larger surgical valve size, supra-annular transcatheter heart valve type, as well as higher transcatheter heart valve implantation depth, have all been shown to reduce the incidence of elevated post-procedural gradients. With greater understanding of technical considerations and surgical planning, valve-in-valve procedures could be more effective and eventually may become the standard of care for our increasingly ageing and comorbid population with failed surgical bioprostheses.