Successful deployment of a transcatheter aortic valve in bicuspid aortic stenosis: role of imaging with multislice computed tomography

Fragmentation of Different Calcification Growth Patterns in Bicuspid Valves During Balloon Valvuloplasty Procedure

This study focuses on the calcification development and routes of type-1 bicuspid aortic valves based on CT scans and the effect of the unique geometrical shapes of calcium deposits on their fragmentation under balloon valvuloplasty procedures. Towards this goal, the novel Reverse Calcification Technique (RCT), which can predict the calcification progression leading to the current state based on CT scans, is utilized for n = 26 bicuspid aortic valves patients. Two main calcification patterns of type-1 bicuspid aortic valves were identified; asymmetric and symmetric with either partial or full arcs and circles. Subsequently, a calcification fragmentation biomechanical model was introduced to study the balloon valvuloplasty procedure prior to transcatheter aortic valve replacement implantation that allows better device expansion. To achieve this goal, six representative stenotic bicuspid aortic valves of different calcification patterns were investigated. It was found that the distinct geometrical shape of the calcium deposits had a significant effect on the cracks' initiations. Full or partial circle deposits had stronger resistance to fragmentation and mainly remained intact, yet, arc-shaped pattern deposits resulted in multiple cracks in bottleneck regions. The proposed biomechanical computational models could help assess calcification fragmentation patterns toward improving treatment approaches in stenotic bicuspid aortic valve patients, particularly for the off-label use of transcatheter aortic valve replacement.

Biomechanical modeling of transcatheter aortic valve replacement in a stenotic bicuspid aortic valve: deployments and paravalvular leakage

Calcific aortic valve disease (CAVD) is characterized by stiffened aortic valve leaflets. Bicuspid aortic valve (BAV) is the most common congenital heart disease. Transcatheter aortic valve replacement (TAVR) is a treatment approach for CAVD where a stent with mounted bioprosthetic valve is deployed on the stenotic valve. Performing TAVR in calcified BAV patients may be associated with post-procedural complications due to the BAV asymmetrical structure. This study aims to develop refined computational models simulating the deployments of Evolut R and PRO TAVR devices in a representative calcified BAV. The paravalvular leakage (PVL) was also calculated by computational fluid dynamics simulations. Computed tomography scan of severely stenotic BAV patient was acquired. The 3D calcium deposits were generated and embedded inside a parametric model of the BAV. Deployments of the Evolut R and PRO inside the calcified BAV were simulated in five bioprosthesis leaflet orientations. The hypothesis of asymmetric and elliptic stent deployment was confirmed. Positioning the bioprosthesis commissures aligned with the native commissures yielded the lowest PVL (15.7 vs. 29.5 mL/beat). The Evolut PRO reduced the PVL in half compared with the Evolut R (15.7 vs. 28.7 mL/beat). The proposed biomechanical computational model could optimize future TAVR treatment in BAV patients. Graphical abstract.

Role of Echocardiography Before Transcatheter Aortic Valve Implantation (TAVI)

Aortic stenosis (AS) is the most common primary valve disorder in the elderly with an increasing prevalence; transcatheter aortic valve implantation (TAVI) has become an accepted alternative to surgical aortic valve replacement (AVR) in the high risk or inoperable patient. Appropriate selection of patients for TAVI is crucial and requires a multidisciplinary approach including cardiothoracic surgeons, interventional cardiologists, anaesthetists, imaging experts and specialist nurses. Multimodality imaging including echocardiography, CT and MRI plays a pivotal role in the selection and planning process; however, echocardiography remains the primary imaging modality used for patient selection, intra-procedural guidance, post-procedural assessment and long-term follow-up. The contribution that contemporary transthoracic and transoesophageal echocardiography make to the selection and planning of TAVI is described in this article.

Efficacy and Safety of Transcatheter Aortic Valve Implantation for Bicuspid Aortic Valves: A Systematic Review and Meta-Analysis

PURPOSE

To elucidate the performance of transcatheter aortic valve implantation (TAVI) in bicuspid aortic valve (BAV) patients through a systematic review and meta-analysis.

METHODS

A systematic literature review was performed by searching eligible articles in PubMed, Medline, EMBASE, Google Scholar and CNKI. Meta-analysis of included case-control/cohort studies was further conducted. Relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were used to compare clinical outcomes of BAV patients and non-BAV patients.

RESULTS

A total of 17 articles including eight case reports, four case series and five case-control/cohort studies with 166 BAV patients were analyzed. Device success rate achieved for TAVI in this cohort of BAV patients was 95.2%. The 30-day mortality rate was 8.4%, and the medium-term (range from 6 months to 2 years) mortality rate reported was 17.9%. Overall, the performance of TAVI in BAV patients was comparable to that in non-BAV patients, as reported by the included case-control/cohort studies (30-day mortality rate: RR = 1.05, 95%CI 0.57-1.95, p = 0.87; Device success rate: RR = 1.00, 95%CI 0.95-1.05, p = 0.94; Incidence of moderate to severe paravalvular regurgitation: RR = 1.25, 95%CI 0.85-1.84, p = 0.25).

CONCLUSION

The present study suggested that TAVI may be a feasible and safe treatment modality for BAV patients.

The expanding indications of transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI), also known as transcatheter aortic valve replacement, is increasingly performed worldwide and is a technology that is here to stay. It has become the treatment of choice for inoperable patients and an alternative option for patients at high surgical risk with severe aortic stenosis. Early results of TAVI in intermediate-risk patients appear promising although larger randomized trial results are awaited before the widespread adoption of this technology in this big pool of patients. In patients with bicuspid aortic stenosis and degenerated surgical bioprostheses, TAVI has been shown to be feasible and relatively safe, though certain important considerations remain. Indications for TAVI are likely to grow as newer generation and improved devices and delivery systems become available.

Sutureless aortic valve replacement in patients who have bicuspid aortic valve

OBJECTIVE

Bicuspid aortic valve (BAV) is generally considered to be a contraindication to sutureless aortic valve replacement (AVR). The aim of this study was to evaluate the feasibility and perioperative outcomes of this technique in patients with BAV.

METHODS

From June 2011 to January 2014, a total of 25 patients who underwent sutureless AVR had documented BAV. Thirteen patients (52%) had median sternotomy, and 12 patients (48%) a minimally invasive approach.

RESULTS

The study population included 17 (68%) men with a median age of 77.8 ± 5.4 years. The mean EuroSCORE II was 3.4% ± 2.6%. Concomitant procedures included coronary artery bypass grafting in 8 patients (32%), 2 AVRs (8%), 1 mitral valve repair (4%), 1 septal myomectomy (4%), and 1 atrial septal defect closure (4%). The mean transaortic valve gradient decreased from 49.4 ± 15.7, to 14.5 ± 5.4 mm Hg postoperatively. The mean aortic valve area increased from 0.78 ± 0.18, to 1.75 ± 0.43 cm(2) postoperatively. Five patients (20%) suffered from atrioventricular block that required permanent pacemaker implantation. Two patients (8%) suffered a stroke. No major paravalvular leakage occurred, and no postoperative valve migration. In-hospital mortality occurred in 1 patient (4%). The mean intensive care unit length of stay was 3 ± 2 days postoperatively.

CONCLUSIONS

This study demonstrates that a sutureless aortic valve can be deployed in patients with BAV without increasing the risk of paravalvular leakage. BAV should not be considered a contraindication to sutureless AVR.

Current topics on bicuspid aortic valve: clinical aspects and surgical management

Bicuspid aortic valve (BAV) has been identified as the most common heart valve anomaly and is considered to be a heritable disorder that affects various cardiovascular disorders, including aortopathy. Current topics regarding the clinical management of BAV including surgical strategies with or without concomitant aortic repair or replacement are attracting interest, in addition to the pathological and morphological aspects of BAV as well as aortopathy. However, surgical indications are still being debated and are dependent on current clinical guidelines and surgeons' preferences. Although clinical guidelines have already been established for the management of BAV with or without aortopathy, many studies on clinical management and surgical techniques involving various kinds of subjects have previously been published. Although a large number of studies concerning the clinical aspects of BAV have been reviewed in detail, controversy still surrounds the clinical and surgical management of BAV. Therefore, surgeons should carefully consider valve pathology when deciding whether to replace the ascending aorta. In this review, we summarized current topics on BAV and the surgical management of diseased BAV with or without aortopathy based on previous findings, including catheter-based interventional management.

Practical update on imaging and transcatheter aortic valve implantation

After very rapid advances in the development of the technique and devices, transcatheter aortic valve implantation (named TAVI or TAVR), is today a reality that is here to stay. It has become the minimally-invasive treatment option for high-risk and non-surgical patients with severe symptomatic aortic stenosis. Requiring the participation of a multidisciplinary team for its implementation, cardiac imaging plays an important role. From pre-assessment to determine the suitability of the patient, the access site, the type of device, to the guidance during the procedure, and ultimately the long term monitoring of the patient. Correct selection of the patient and device, correct placement of the stent-valve and early detection of complications are of paramount importance for procedural success and for patient outcome. Each technique has advantages and disadvantages, being the cardiologist who will determine the best approach according to the type of patient and the expertise of the center in each one of them. This article summarizes the last contributions of the most common used imaging techniques, in each step of the procedure.

Comparison of the effectiveness of transcatheter aortic valve implantation in patients with stenotic bicuspid versus tricuspid aortic valves (from the German TAVI Registry)

Patients with bicuspid aortic valves (BAVs) are considered a relative contraindication to transcatheter aortic valve implantation (TAVI). One of the main reasons is the presumed risk for residual aortic regurgitation (AR). However, case reports and small case series have suggested that TAVI can be successfully performed with acceptable clinical outcomes in high-risk patients with BAV. Within the large German TAVI Registry, we sought to evaluate TAVI in older high-risk patients with BAV. From January 2009 to June 2010, a total of 1,424 patients with severe aortic stenosis undergoing TAVI were prospectively enrolled into the German TAVI Registry. For the present analysis, patients with valve-in-valve procedures were excluded and those with BAV (n = 38, 3%) were compared with those with tricuspid aortic valve (TAV; n = 1357, 97%). Patient characteristics did not markedly differ and procedural success was very high in both groups. There was a higher rate of relevant AR (≥II) after TAVI among patients with BAV (25 vs 15%, p = 0.05), whereas pacemakers were more often implanted in patients with TAV (17% vs 35%, p = 0.02). Thirty-day mortality rate was similar in both cohorts (11% vs 11%). In a Cox proportional regression analysis, BAV was not associated with higher 1-year mortality rate (hazard ratio 0.64, 95% confidence interval 0.29 to 1.41). In selected patients with BAV, TAVI can be performed with a satisfactory clinical result. Although the risk for relevant AR seems to be greater among patients with BAV, 30-day and 1-year mortality rates were not elevated compared with patients with TAV.

Transcatheter Aortic Valve Implantation for Patients With Severe Bicuspid Aortic Valve Stenosis

Background—

Bicuspid aortic valve (BAV) is regarded as a relative contraindication to transcatheter aortic valve implantation attributable to the risk of uneven expansion of the bioprosthesis. The purpose of this study was to evaluate the efficacy and safety of transcatheter aortic valve implantation in patients with BAV.

Methods and Results—

Of 470 patients included in our prospective transcatheter aortic valve implantation database (October 2006–January 2012), 229 consecutive patients undergoing both echocardiography and multidetector computed tomography were analyzed. We compared clinical outcomes in patients with vs patients without BAV. In this series of 229 patients, BAV was detected by multidetector computed tomography in 21 patients (9.2%). BAV was identified by transthoracic and transoesophagal echocardiography in only 9 of these 21 patients. Patients were 83.1±6.6 years old, and European system for cardiac operative risk evaluation score was 20.0%±11.4%. The BAV group was similar to the non-BAV group except for diabetes mellitus (4.8% vs 24.0%; P =0.05). The aortic annulus diameter in BAV patients was not significantly larger by multidetector computed tomography (24.7±3.0 vs 23.7±1.9 mm; P =0.07). The CoreValve was used more frequently in the BAV group (47.6% vs 16.3%; P =0.002). There was no significant difference in device success (100% vs 92.8%; P =0.37), risk of annulus rupture (0% vs 1.4%; P =1.00), or valve migration (0% vs 1.4%; P =1.00) in BAV patients compared with non-BAV patients. Postprocedural mean gradient (10.0±3.4 vs 9.7±4.1 mm Hg; P =0.58), aortic regurgitation ≥2 of 4 (19.0% vs 14.9%; P =0.54), 30-day mortality (4.8% vs 8.2%; P =1.00), and 30-day combined safety end point (14.3% vs 13.5%; P =1.00) were also similar in both groups.

Conclusions—

In selected BAV patients, transcatheter aortic valve implantation may be associated with low complication rate, efficacy, and acceptable outcomes similar to those in non-BAV patients.

Transapical aortic valve implantation in bicuspid aortic valves: must be an absolute contraindication?

Transcatheter Aortic Valve Implantation (TAVI) is a new therapeutic option for patients with severe aortic stenosis with unacceptable surgical risk for conventional aortic valve surgery. A Bicuspid Aortic Valve (BAV) is the most common congenital cardiac disorder (1% of the population) and currently is considered exclusion criteria for TAVI, because it predicts an increased risk of adverse aortic events as incomplete sealing, severe paravalvular regurgitation, or dislocation due to more frequent elliptic shape and asymmetric calcifications in BAV annulus.

Only few cases have been published in recent literature, so in this case report we illustrate our experience and management of TAVI in a BAV, with excellent outcomes and no late complications at 1 year follow-up.

We believe that currently the presence of a BAV might not be considered an absolute contraindication for TAVI, because although there is no sufficient data for assess the safety or efficacy of TAVI in BAV, this case report shows that it could be performed safely in selected patients with unacceptable surgical risk after an extensive preoperative evaluation, avoiding this procedure in patients with bad prognostic factors as huge and heavy calcifications, asymmetric valves, elliptic annulus or small distance from leaflets to coronary ostia. Each case must be individualized, being alert at follow-up because the risk of late complications.

Multidetector row computed tomography assessment of the native aortic and mitral valve: a call for routine assessment of left-sided heart valves during coronary computed tomography

Aortic valve stenosis and mitral valve regurgitation are the most common valvular heart diseases (VHD) in Western countries. In daily clinical practice, the diagnosis and evaluation of the severity of VHD is based on clinical findings and imaging. Transthoracic echocardiography is the preferred imaging technique for the initial evaluation of VHD. In patients with inconclusive transthoracic echocardiography, transoesophageal echocardiography can have additional diagnostic value. Cardiac multidetector row computed tomography (MDCT) has proven to have diagnostic value in the evaluation of coronary artery disease in symptomatic patients with a low-to-intermediate pretest probability. The images acquired for coronary assessment also contain diagnostic information on heart valves. The purpose of this review was to discuss the diagnostic value of MDCT for the evaluation of left-sided VHD. We provide an overview of the literature comparing echocardiography and MDCT for VHD assessment focusing on aortic valve and mitral valve disease, and we present clinical recommendations.

Feasibility and outcomes of transcatheter aortic valve implantation in high-risk patients with stenotic bicuspid aortic valves

Little is known about transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve stenosis, which usually represents a contraindication. The aim of this study was to assess the feasibility and the results of TAVI in this patient subset. Of 316 high-risk patients with severe aortic stenosis who underwent TAVI from January 2009 to January 2012, 15 (5%) had documented bicuspid aortic valves. They were treated using a transarterial approach, using the Medtronic CoreValve system. Patients were aged 80 ± 10 years, in New York Heart Association functional classes III and IV. The mean aortic valve area was 0.8 ± 0.3 cm(2), and the mean gradient was 60 ± 19 mm Hg. The mean calcium score, calculated using multislice computed tomography, was 4,553 ± 1,872 arbitrary units. The procedure was successful in all but 1 patient. Major adverse events, according to Valvular Academic Research Consortium definitions, were encountered in 1 patient (death). The mean postimplantation prosthetic gradient was 11 ± 4 mm Hg, and ≤1+ periprosthetic leaks were observed in all but 2 patients. The mean prosthetic ellipticity index was 0.7 ± 0.2 at the level of the native annulus and 0.8 ± 0.2 at the level of the prosthetic leaflets. After a mean follow-up period of 8 ± 7 months, 1 patient had died from aortic dissection; there were no additional adverse events. All but 2 hospital survivors were in New York Heart Association class I or II. In conclusion, the present series suggests that transarterial Medtronic CoreValve implantation is feasible in selected patients with bicuspid aortic valve and may lead to short-term hemodynamic and clinical improvement.

Patient selection for transcatheter aortic valve implantation: patient risk profile and anatomical selection criteria

Patient selection plays a crucial role in the success of transcatheter aortic valve implantation (TAVI). It requires meticulous attention to the smallest of details and needs to be performed in a systematic manner for every patient. In essence, the patient must be assessed from access to implantation site. Becoming over "complacent" and "routine" may lead to failure and impact patient safety. TAVI is indicated for high or prohibitive surgical risk patients with severe aortic stenosis. Some patients, however, are too high risk even for TAVI. In addition to patient risk evaluation, anatomical selection criteria need to be considered. Multimodality imaging, using a combination of angiography, echocardiography and multislice computed tomography, is necessary to determine the anatomical suitability for the procedure.

Successful transapical aortic valve implantation in a congenital bicuspid aortic valve

Transcatheter stent-valve implantation in stenosed congenital bicuspid aortic valves is under debate. Heavily calcified elliptic bicuspid valves represent a contraindication to catheter-based valve therapies because of a risk of stent-valve displacement, distortion, or malfunctioning after the implantation. In this case report we illustrate our experience with a patient suffering from stenosed congenital bicuspid aortic valve who successfully underwent a transapical 26-mm Edwards Sapien stent-valve (Edwards Lifesciences Inc, Irvine, CA) implantation. Postoperative distortion, malfunctioning, and paravalvular leaks were not detected.

Transcatheter aortic valve implantation: role of multimodality cardiac imaging

Current evidence based on more than 8000 high-risk patients with severe aortic stenosis has demonstrated that transcatheter aortic valve implantation (TAVI) is a feasible alternative to surgical aortic valve replacement in selected patients. Despite current promising results on hemodynamic and clinical improvements, there are several unresolved safety issues, such as the frequency of vascular complications, postprocedural paravalvular leak, atrioventricular heart block and stroke. Multimodality cardiac imaging may help to minimize these complications and may play a central role before (optimizing patient selection, selection of appropriate prosthesis size and anticipating the procedural approach), during and after TAVI (evaluating the immediate and long-term procedural results). This article reviews the state-of-the-art TAVI procedures and the role that multimodality cardiac imaging plays before, during and after TAVI.