Transcatheter Aortic Valve Implantation

Platform Selection for Patients Undergoing Transcatheter Aortic Valve Replacement: A Practical Approach

Transfemoral transcatheter aortic valve Replacement (TAVR) has become the standard therapy for patients with severe aortic stenosis in patients over 75 years old in Europe or 65 years old in the United States, regardless of the surgical risk. Furthermore, iterations of existing transcatheter aortic valves (TAVs), as well as devices with novel concepts, have provided substantial improvements with respect to the limitations of previous-generation devices. Hence, treatment of a broader spectrum of patients has become feasible, and a sophisticated selection of the appropriate TAV tailored to patients' anatomy and comorbidities is now possible. Anatomy, patient characteristics, and operator experience must all inform proper device selection. This review describes the features and performance of the current generation of TAVs with the aim of providing a practical approach for clinicians when selecting the appropriate TAV for a specific patient.

The impact of transcatheter aortic valve implantation (TAVI) on mitral regurgitation - a single center study

BACKGROUND

The coexistence of mitral regurgitation (MR) and severe aortic stenosis (AS) has been associated with worse outcomes in patients undergoing transcatheter aortic valve implantation (TAVI). Herein, the aim was to assess the etiology and degree of MR in an unselected TAVI population and investigate the impact of MR reduction at mid-term follow-up.

METHODS

Patients subjected to TAVI as a treatment for severe AS in a single center were retrospectively analyzed. The primary endpoint was the MR reduction after TAVI. The secondary endpoint was all-cause mortality and heart failure hospitalization at a 3-year follow-up.

RESULTS

Patients undergoing TAVI (n = 283) in the years 2017-2019 were screened for the presence of hemodynamically significant MR. Sixty-nine subjects (24.4%) with severe (16, 23.2%) and moderate (53, 76.8%) MR were included. The primary MR was predominant (39 subjects, 56.5%). The median age of the patients was 82 years. MR improved in 25 patients (36.2%, p < 0.001). Baseline severe MR was more prone to reduce (8 subjects, 50%) than moderate (17 subjects, 32.1%, p = 0.04). The primary MR improved in 14 patients (35.9%), while secondary in 11 patients (36.7%, p = 1). Patients showing MR reduction had lower mortality (8 vs. 29.55%, p = 0.047) and were less frequently hospitalized (20 vs. 45.45%, p = 0.03) at 3-year follow-up.

CONCLUSIONS

Hemodynamically significant MR improves after TAVI regardless of its etiology. Moreover, MR reduction after TAVI is associated with better clinical outcomes.

Novel apical-to-femoral rail technique for horizontal aorta in transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has emerged as a viable treatment option for patients with severe aortic stenosis regardless of its surgical risk stratification (Otto et al., 2021). Aortic angulation is usually measured as the angle between the horizontal and the aortic annulus planes based on preproced‍ural multidetector computed tomography (MDCT) (Al-Lamee et al., 2011). Extremely horizontal aorta, defined as an aortic angulation greater than 70°, is an unfavorable anatomic structure that poses particular technical challenges for TAVR. Abramowitz et al. (2016) have proved that an extremely horizontal aorta increased the risk of procedural complications, such as lower device success rates, more moderate or even severe perivalvular leakage (PVL), and the need for second valve implantation. Because of the long stent frame, inflexibility, and non-steerability, it is challenging to pass the delivery system of self-expanding valves (SEVs) through an extremely horizontal aorta. As a result, patients with an extremely horizontal aorta have always been excluded from the clinical trials of TAVR, and transfemoral (TF)-TAVR with SEV is considered as an "off-label" use of TAVR (Adams et al., 2014; Kaneko et al., 2020). Herein, we present a technically difficult case, in which a patient with an extremely horizontal aorta underwent TF-TAVR with SEV by applying a unique apical-to-femoral rail strategy.

Aortic angle distribution and predictors of horizontal aorta in patients undergoing transcatheter aortic valve replacement

BACKGROUND

Horizontal aorta (HA) is an anatomical feature that can pose significant technical challenges for the successful positioning of the bioprosthetic valve during transcatheter aortic valve replacement (TAVR). Physiological range of aortic angle (AA) is unknown; hence there is no cutoff AA for classifying HA. Moreover, patient characteristics predicting HA are under-investigated.

METHODS

This was a retrospective analysis of prospective collected data from 16 heart valve centers in Europe. The study utilized a common dataset with a priori agreed-upon definitions and variables. Eligible patients underwent TAVR between 2014 and 2020 and had multidetector computed tomographic imaging data available for determining the AA. The analysis described the distribution of AA and potential predictors of HA. Inter-center variability was also explored.

RESULTS

For 4022 patients analyzed, the mean AA ± standard deviation was 49.4° ± 9.4° (median 49°, inter-quartile range [IQR] 12°, range 18-90°). There was no significant difference in mean AA between men and women (49.4° ± 9.1° vs. 49.6° ± 9.3°, respectively; p = 0.53); therefore, 49.4° was accepted as the cutoff value for HA in subsequent analyses. Covariates significantly associated with HA included age (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01-1.04, p < 0.001), body mass index (OR: 1.06, 95% CI: 1.05-1.08, p < 0.01), previous cardiac surgery (OR: 0.58, 95% CI: 0.45-0.75, p < 0.001), and porcelain aorta (OR: 0.66, 95% CI: 0.52-0.85, p = 0.001). Some inter-center variability was observed.

CONCLUSIONS

We defined 49.4° as the mean AA, and also associated predictors of HA in a large case series of patients with severe aortic stenosis candidates for TAVR.

Diabetes mellitus is not associated with worse vascular outcome following percutaneous transfemoral transcatheter aortic valve implantation

Background: Transcatheter aortic valve implantation (TAVI) is an alternative to open surgical aortic valve replacement and the impact of diabetes on vascular outcomes is worth of investigation. The aim of our study was to determine if diabetic patients had distinct pre-operative characteristics compared to non-diabetics and to evaluate the impact of the disease on vascular outcomes.Methods: Four hundred consecutive patients who underwent TAVI with percutaneous transfemoral access were retrospectively included. Vascular outcomes were classified according to the Valve Academic Research Consortium 2 classification.Results: Seventy-eight (19.5%) patients were diabetics. Compared to non-diabetics, diabetic patients were younger and had significantly higher body mass index (29.7+/- 0.7 kg/m² vs 26.8+/- 0.3, p < .0001), higher proportion of associated dyslipidemia (34.6% vs 11.5%, p < .0001) and arterial hypertension (60% vs 38.2%, p = .0009). Anatomical characteristics of the vascular access and procedural characteristics did not differ among the groups. No significant difference was observed in the incidence of major and minor vascular complications and 30-day post-operative mortality between diabetic and non-diabetic patients (2.6% vs 1.9%, p = .6916).Conclusion: Diabetes is not associated with worse vascular outcome following TAVI suggesting that the vascular access can be managed safely in these patients.

Radial Force: An Underestimated Parameter in Oversizing Transcatheter Aortic Valve Replacement Prostheses: In Vitro Analysis with Five Commercialized Valves

The goal is to inform in depth on transcatheter aortic valve replacement (TAVR) prosthesis mechanical behavior, depending on frame type, design, and size, and how it crucially impacts the oversizing issue in clinical use, and ultimately the procedure outcome. Transcatheter aortic valve replacement is an established therapy for high-risk patients suffering from aortic stenosis, and the indication for TAVR is progressively expanding to intermediate-risk patients. Choosing the optimal oversizing degree is crucial to safely anchor the TAVR valve-which involves limiting the risks for embolism, aortic regurgitation, conductance disturbance, or annulus rupture-and to increase the valve prosthesis performance. The radial force (RF) profiles of five TAVR prostheses were measured in vitro: the CoreValve 23 and 26 (Medtronic, Minneapolis, MN), the Acurate neo S (Symetis, Écublens, Vaud, Switzerland), and the SAPIEN XT 23 and 26 (Edwards Lifesciences, Irvine, CA). Measurements were run with the RX Machine equipment (Machine Solutions Inc., Flagstaff, AZ), which is used in ISO standard tests for intravascular stents. Test protocols were adapted for TAVR prostheses. With the prostheses RF profiles' results, mechanical behavior differences could be described and discussed in terms of oversizing strategy and clinical impact for all five valves. Besides, crossing the prostheses' RF profiles with their recommended size windows made the assessment of borderline size cases possible and helped analyze the risks when accurate measurement of patient aortic annulus proves difficult. The prostheses' RF profiles bring new support in clinical decision-making for valve type and size in patients.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Transcatheter Aortic Valve Implantation in Morphologically Complex Root Aneurysms

Performing transcatheter aortic valve implantation in the presence of aneurysmatic aortopathy is widely contraindicated but needs to be taken into account as a bailout strategy in selected patients. Deliberate preoperative assessment of measurements becomes the crucial key element in this context. After meticulous valve selection, retrograde access is obtained through the right subclavian artery additionally serving as a backup arterial cannulation site in case of conversion. Transcatheter aortic valve implantation is then performed through the transapical route. Transcatheter aortic valve implantation in complex aneurysmatic aortic morphology is feasible in highly selected patients after comprehensive preoperative evaluation. The present article describes our initial experience, safeguards, and technical details.

A 7-Year Single-Center Experience of Transfemoral TAVI: Evolution of Surgical Activity and Impact on Vascular Outcome

Transcatheter aortic valve implantation (TAVI) has become a well-established alternative to open surgery to treat aortic stenosis. We describe our 7-year TAVI experience using transfemoral access and identity changes in surgical activity and evaluate its impact on postoperative vascular outcomes. Consecutive patients (N = 340) who underwent TAVI with percutaneous transfemoral access were retrospectively included and divided into 4 quartiles according to the date of intervention. Vascular outcomes were classified according to the Valve Academic Research Consortium 2 classification. The number of patients who underwent transfemoral TAVI increased over time and their clinical characteristics evolved, with a lower Society of Thoracic Surgeons score and less comorbidities. The material used evolved and TAVI could be performed despite higher iliac calcification and tortuosity scores. With experience, the procedural time, the postoperative length of stay at hospital, and the 30-day postoperative mortality significantly decreased. No significant change was observed for vascular outcome, except for minor hematoma. We witnessed an increase in transfemoral TAVI procedure, with changes in clinical and procedural characteristics associated with an improvement in postoperative outcomes.

Resource utilization and procedure-related costs associated with transfemoral transcatheter aortic valve replacement

AIMS

Transcatheter aortic valve implantation (TAVI) is an alternative to surgical valve replacement for patients with aortic stenosis (AS). This study assessed the impact of changing from a self-expandable (SE) valve to a balloon-expandable (BE) valve on healthcare resource use and procedural costs in a population of inoperable AS patients.

METHODS

In this retrospective single center study, data for 195 patients who received either an SE or a BE valve between 2010-2014 were collected. Procedural and post-procedural healthcare resource use and cost parameters were determined for the two groups.

RESULTS

The study showed that overall procedural time, including time required by medical personnel, was significantly shorter for TAVI using a BE compared with an SE valve. Post-surgery, patients in the BE valve group had significantly shorter hospital stays than the SE valve group, including significantly fewer days spent in the intensive care unit (ICU). Additionally, trends towards reduced 30-day mortality, incidence of new permanent pacemaker implantation, and incidence of blood transfusion were observed in the BE valve group compared with the SE valve group. Finally, total procedural costs were 24% higher in the SE compared with the BE valve group.

LIMITATIONS

The BE valve data were acquired in a single year, whereas the SE valve data were from a 5-year period. However, a year-by-year analysis of patient characteristics and study outcomes for the SE valve group showed few significant differences over this 5-year period.

CONCLUSIONS

Overall, changing from an SE to a BE valve for TAVI in patients with severe AS reduced both healthcare resource use and procedure-related costs, while maintaining patient safety. For healthcare providers, this could increase efficiency and capacity within the healthcare system, with the added advantage of reducing costs.

ANMCO/SIC/SICI-GISE/SICCH Executive Summary of Consensus Document on Risk Stratification in elderly patients with aortic stenosis before surgery or transcatheter aortic valve replacement

Aortic stenosis is one of the most frequent valvular diseases in developed countries, and its impact on public health resources and assistance is increasing. A substantial proportion of elderly people with severe aortic stenosis is not eligible to surgery because of the advanced age, frailty, and multiple co-morbidities. Transcatheter aortic valve implantation (TAVI) enables the treatment of very elderly patients at high or prohibitive surgical risk considered ineligible for surgery and with an acceptable life expectancy. However, a significant percentage of patients die or show no improvement in quality of life (QOL) in the follow-up. In the decision-making process, it is important to determine: (i) whether and how much frailty of the patient influences the risk of procedures; (ii) how the QOL and the individual patient's survival are influenced by aortic valve disease or from other associated conditions; and (iii) whether a geriatric specialist intervention to evaluate and correct frailty or other diseases with their potential or already manifest disabilities can improve the outcome of surgery or TAVI. Consequently, in addition to risk stratification with conventional tools, a number of factors including multi-morbidity, disability, frailty, and cognitive function should be considered, in order to assess the expected benefit of both surgery and TAVI. The pre-operative optimization through a multidisciplinary approach with a Heart Team can counteract the multiple damage (cardiac, neurological, muscular, respiratory, and kidney) that can potentially aggravate the reduced physiological reserves characteristic of frailty. The systematic application in clinical practice of multidimensional assessment instruments of frailty and cognitive function in the screening and the adoption of specific care pathways should facilitate this task.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Is Transcatheter Aortic Valve Implantation of Living Tissue-Engineered Valves Feasible? An In Vitro Evaluation Utilizing a Decellularized and Reseeded Biohybrid Valve

Transcatheter aortic valve implantation (TAVI) is a fast-growing, exciting field of invasive therapy. During the last years many innovations significantly improved this technique. However, the prostheses are still associated with drawbacks. The aim of this study was to create cell-seeded biohybrid aortic valves (BAVs) as an ideal implant by combination of assets of biological and artificial materials. Furthermore, the influence of TAVI procedure on tissue-engineered BAV was investigated. BAV (n=6) were designed with decellularized homograft cusps and polyurethane walls. They were seeded with fibroblasts and endothelial cells isolated from saphenous veins. Consecutively, BAV were conditioned under low pulsatile flow (500 mL/min) for 5 days in a specialized bioreactor. After conditioning, TAVI-simulation was performed. The procedure was concluded with re-perfusion of the BAV for 2 days at an increased pulsatile flow (1100 mL/min). Functionality was assessed by video-documentation. Samples were taken after each processing step and evaluated by scanning electron microscopy (SEM), immunohistochemical staining (IHC), and Live/Dead-assays. The designed BAV were fully functioning and displayed physiologic behavior. After cell seeding, static cultivation and first conditioning, confluent cell layers were observed in SEM. Additionally, IHC indicated the presence of endothelial cells and fibroblasts. A significant construction of extracellular matrix was detected after the conditioning phase. However, a large number of lethal cells were observed after crimping by Live/Dead staining. Analysis revealed that the cells while still being present directly after crimping were removed in subsequent perfusion. Extensive regions of damaged cell-layers were detected by SEM-analysis substantiating these findings. Furthermore, increased ICAM expression was detected after re-perfusion as manifestation of inflammatory reaction. The approach to generate biohybrid valves is promising. However, damages inflicted during the crimping process seem not to be immediately detectable. Due to severe impacts on seeded cells, the strategy of living TE valves for TAVI should be reconsidered.

Impact of different aortic valve calcification patterns on the outcome of transcatheter aortic valve implantation: A finite element study

Transcatheter aortic valve implantation (TAVI) can treat symptomatic patients with calcific aortic stenosis. However, the severity and distribution of the calcification of valve leaflets can impair the TAVI efficacy. Here we tackle this issue from a biomechanical standpoint, by finite element simulation of a widely adopted balloon-expandable TAVI in three models representing the aortic root with different scenarios of calcific aortic stenosis. We developed a modeling approach realistically accounting for aortic root pressurization and complex anatomy, detailed calcification patterns, and for the actual stent deployment through balloon-expansion. Numerical results highlighted the dependency on the specific calcification pattern of the "dog-boning" of the stent. Also, local stent distortions were associated with leaflet calcifications, and led to localized gaps between the TAVI stent and the aortic tissues, with potential implications in terms of paravalvular leakage. High stresses were found on calcium deposits, which may be a risk factor for stroke; their magnitude and the extent of the affected regions substantially increased for the case of an "arc-shaped" calcification, running from commissure to commissure. Moreover, high stresses due to the interaction between the aortic wall and the leaflet calcifications were computed in the annular region, suggesting an increased risk for annular damage. Our analyses suggest a relation between the alteration of the stresses in the native anatomical components and prosthetic implant with the presence and distribution of relevant calcifications. This alteration is dependent on the patient-specific features of the calcific aortic stenosis and may be a relevant indicator of suboptimal TAVI results.

Robot-assisted real-time magnetic resonance image-guided transcatheter aortic valve replacement

BACKGROUND

Real-time magnetic resonance imaging (rtMRI)-guided transcatheter aortic valve replacement (TAVR) offers improved visualization, real-time imaging, and pinpoint accuracy with device delivery. Unfortunately, performing a TAVR in a MRI scanner can be a difficult task owing to limited space and an awkward working environment. Our solution was to design a MRI-compatible robot-assisted device to insert and deploy a self-expanding valve from a remote computer console. We present our preliminary results in a swine model.

METHODS

We used an MRI-compatible robotic arm and developed a valve delivery module. A 12-mm trocar was inserted in the apex of the heart via a subxiphoid incision. The delivery device and nitinol stented prosthesis were mounted on the robot. Two continuous real-time imaging planes provided a virtual real-time 3-dimensional reconstruction. The valve was deployed remotely by the surgeon via a graphic user interface.

RESULTS

In this acute nonsurvival study, 8 swine underwent robot-assisted rtMRI TAVR for evaluation of feasibility. Device deployment took a mean of 61 ± 5 seconds. Postdeployment necropsy was performed to confirm correlations between imaging and actual valve positions.

CONCLUSIONS

These results demonstrate the feasibility of robotic-assisted TAVR using rtMRI guidance. This approach may eliminate some of the challenges of performing a procedure while working inside of an MRI scanner, and may improve the success of TAVR. It provides superior visualization during the insertion process, pinpoint accuracy of deployment, and, potentially, communication between the imaging device and the robotic module to prevent incorrect or misaligned deployment.

Real-time magnetic resonance imaging-guided transcatheter aortic valve replacement

OBJECTIVES

To demonstrate the feasibility of Real-time magnetic resonance imaging (rtMRI) guided transcatheter aortic valve replacement (TAVR) with an active guidewire and an MRI compatible valve delivery catheter system in a swine model.

METHODS

The CoreValve system was minimally modified to be MRI-compatible by replacing the stainless steel components with fluoroplastic resin and high-density polyethylene components. Eight swine weighing 60-90 kg underwent rtMRI-guided TAVR with an active guidewire through a left subclavian approach.

RESULTS

Two imaging planes (long-axis view and short-axis view) were used simultaneously for real-time imaging during implantation. Successful deployment was performed without rapid ventricular pacing or cardiopulmonary bypass. Postdeployment images were acquired to evaluate the final valve position in addition to valvular and cardiac function.

CONCLUSIONS

Our results show that the CoreValve can be easily and effectively deployed through a left subclavian approach using rtMRI guidance, a minimally modified valve delivery catheter system, and an active guidewire. This method allows superior visualization before deployment, thereby allowing placement of the valve with pinpoint accuracy. rtMRI has the added benefit of the ability to perform immediate postprocedural functional assessment, while eliminating the morbidity associated with radiation exposure, rapid ventricular pacing, contrast media renal toxicity, and a more invasive procedure. Use of a commercially available device brings this rtMRI-guided approach closer to clinical reality.

Valve-in-Valve Therapy for Failed Surgical Bioprosthetic Valves: Clinical Results and Procedural Guidance

With improved life expectancy and increased use of bioprosthetic heart valves, more elderly and frail patients present with degenerative surgical heart valve disease. The valve-in-valve procedure is an attractive alternative to a conventional open redo procedure. Although it is a novel extension of established transcatheter aortic valve implantation for severe aortic stenosis in a high-risk population, it is gaining momentum worldwide, particularly for aortic and mitral positions. Success depends on the operator being familiar with emerging transcatheter heart valve technology and morphology as well as that of the existing surgical heart valve, patient selection, accurate sizing, an ideal implantation position.

Transapical sutureless aortic valve implantation under magnetic resonance imaging guidance: Acute and short-term results

OBJECTIVES

Despite the increasing success and applicability of transcatheter aortic valve replacement, 2 critical issues remain: the durability of the valves, and the ideal imaging to aid implantation. This study was designed to investigate the transapical implantation of a device of known durability using real-time magnetic resonance imaging (MRI) guidance.

METHODS

A sutureless aortic valve was used that employs a self-expanding nitinol stent and is amenable to transapical delivery. MRI (1.5-T) was used to identify the anatomic landmarks in 60-kg Yucatan swine. Prostheses were loaded into an MRI-compatible delivery device with an active guidewire to enhance visualization. A series of acute feasibility experiments were conducted (n = 10). Additional animals (n = 6) were allowed to survive and had follow-up MRI scans and echocardiography at 90 days postoperatively. Postmortem gross examination was performed.

RESULTS

The valve was MRI compatible and created no significant MRI artifacts. The 3 commissural struts were visible on short-axis view; therefore, coronary ostia obstruction was easily avoided. The average implantation time was 65 seconds. Final results demonstrated stability of the implants with preservation of myocardial perfusion and function over 90 days: the ejection fraction was 48% ± 15%; the peak gradient was 17.3 ± 11.3 mm Hg; the mean gradient was 9.8 ± 7.2 mm Hg. Mild aortic regurgitation was seen in 4 cases, trace in 1 case, and a severe central jet in 1 case. Prosthesis positioning was evaluated during gross examination.

CONCLUSIONS

We demonstrated that a sutureless aortic valve can be safely and expeditiously implanted through a transapical approach under real-time MRI guidance. Postimplantation results showed a well-functioning prosthesis, with minimal regurgitation, and stability over time.

Valve-in-valve procedure: importance of the anatomy of surgical bioprostheses

Transcatheter aortic valve implantation is an accepted and established alternative to surgical aortic valve replacement for patients with severe symptomatic aortic valve stenosis and multiple comorbidities that would make open surgery a high-risk option. It has also evolved as a suitable treatment option for degenerative surgical heart valve disease, with considerable experience in the aortic and mitral positions. To enable a successful procedure, avoiding malposition, valve embolization and coronary obstruction, clinicians should be familiar with the design, fluoroscopic appearances and implantation technique of the degenerated surgical bioprosthetic valve in situ, as well as its compatibility with currently available transcatheter valves.

Preinterventional screening of the TAVI patient: how to choose the suitable patient and the best procedure

Transcatheter aortic valve implantation (TAVI) is a novel therapy, which has transformed the management of inoperable patients presenting with symptomatic severe aortic stenosis (AS). It is also a proven and less invasive alternative therapeutic option for high-risk symptomatic patients presenting with severe AS who are otherwise eligible for surgical aortic valve replacement. Patient age is not strictly a limitation for TAVI but since this procedure is currently restricted to high-risk and inoperable patients, it follows that most patients selected for TAVI are at an advanced age. Patient frailty and co-morbidities need to be assessed and a clinical judgment made on whether the patient will gain a measureable improvement in their quality of life. Risk stratification has assumed a central role in selecting suitable patients and surgical risk algorithms have proven helpful in this regard. However, limitations exist with these risk models, which must be understood in the context of TAVI. When making final treatment decisions, it is essential that a collaborative multidisciplinary "heart team" be involved and this is stressed in the most recent guidelines of the European Society of Cardiology. Choosing the best procedure is contingent upon anatomical feasibility, and multimodality imaging has emerged as an integral component of the pre-interventional screening process in this regard. The transfemoral route is now considered the default approach although vascular complications remain a concern. A minimal vessel diameter of 6 mm is required for currently commercial available vascular introducer sheaths. Several alternative access routes are available to choose from when confronted with difficult iliofemoral anatomy such as severe peripheral vascular disease or diffuse circumferential vessel calcification. The degree of aortic valve leaflet and annular calcification also needs to be assessed as the latter is a risk factor for post-procedural paravalvular aortic regurgitation. The ultimate goal of patient selection is to achieve the highest procedural success rate while minimizing complications and to choose patients most likely to derive tangible benefit from this procedure.

Transcatheter aortic valve insertion (TAVI): a review

The introduction of transcatheter aortic valve insertion (TAVI) has transformed the care provided for patients with severe aortic stenosis. The uptake of this procedure is increasing rapidly, and clinicians from all disciplines are likely to increasingly encounter patients being assessed for or having undergone this intervention. Successful TAVI heavily relies on careful and comprehensive imaging assessment, before, during and after the procedure, using a range of modalities. This review outlines the background and development of TAVI, describes the nature of the procedure and considers the contribution of imaging techniques, both to successful intervention and to potential complications.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.

Differences in Outcomes and Indications between Sapien and CoreValve Transcatheter Aortic Valve Implantation Prostheses

Transcatheter aortic valve implantation (TAVI) has emerged as a suitable alternative to surgical valve replacement for patients with severe, symptomatic, calcified aortic stenosis and a background of co-morbidities, which can make surgery a high-risk option. It has also evolved as an alternative for degenerative prosthetic heart valve disease. Since the inception of TAVI in 2002, the two main devices in routine clinical use are the Edwards Sapien valve (since 2006) and the Medtronic CoreValve (since 2007). The more recent Sapien XT valve and Sapien 3 have been in clinical use since 2010 and 2013, respectively. In addition to registry data on these devices, there are a number of completed and ongoing randomised controlled trials, including one comparing the two devices. The aim of this article is to discuss the differences in indications and outcomes between these two prostheses.