Transcatheter Aortic Valve Implantation Prosthesis Research Articles

Surgical treatment of transcatheter aortic valve infective endocarditis.

There is growing interest in infections occurring after transcatheter aortic valve implantation (TAVI). The incidence, and clinical and anatomical features suggest many similarities with prosthetic valve endocarditis. The survival of patients with an infected TAVI prosthesis is generally poor; however, only a minority of them (10%) have undergone treatment with surgical explantation of the infected prosthesis. A literature search was performed using online databases. Papers reporting surgical treatment of TAVI prosthesis infections were retrieved, focusing on pre- and intraoperative characteristics and early outcome. Thirty-seven papers ultimately provided information on 107 patients. Their mean ± standard deviation (SD) age was 76 ± 8 years and 72% were male. The mean ± SD time interval between the TAVI procedure and reoperation was 10 ± 10 months. Annular abscess formation was described in 34% of cases and mitral valve involvement in 31%. All patients underwent TAVI prosthesis explantation and surgical aortic valve replacement; concomitant mitral valve replacement was necessary in 22% of cases. Postoperative in-hospital mortality was 28%. Surgical explantation of infected TAVI prostheses was associated with a high postoperative mortality, although these initial experiences included elderly and high-risk patients. Considering the expansion of TAVI procedures towards younger and lower-risk patients, surgical treatment of TAVI endocarditis may represent the best option for a life-saving procedure.Electronic supplementary materialThe online version of this article (10.1007/s12471-020-01494-y) contains supplementary material, which is available to authorized users.

Intravascular haemolysis after transcatheter aortic valve implantation with self-expandable prosthesis: incidence, severity, and impact on long-term mortality.

We aimed to determine the incidence, severity, and long-term impact of intravascular haemolysis after self-expanding transcatheter aortic valve implantation (TAVI). We believe this should be evaluated before extending the indications of TAVI to younger low-risk patients. Prospective, academic, single centre study of 94 consecutive patients treated with supra-annular self-expandable TAVI prosthesis between April 2009 and January 2014. Haemolysis at 1-year post-TAVI was defined per the published criteria based on levels of haemoglobin, reticulocyte and schistocyte count, lactate dehydrogenase (LDH), and haptoglobin. All patients had long-term clinical follow-up (6 years). The incidence of haemolysis at 1-year follow-up varied between 9% and 28%, based on different haemolysis definitions. Haemolysis was mild in all cases, no patient had markedly increased LDH levels. The presence of moderate/severe paravalvular aortic regurgitation was associated with haemolysis (7.7% vs. 23.1%, P = 0.044) and aortic valve area post-TAVI did not differ between groups with or without haemolysis (1.01 vs. 0.92 cm2/m2, P = 0.23) (definition including schistocyte count). The presence of haemolysis did not have any impact on patient prognosis after 6 years with log-rank test P = 0.80. Intravascular haemolysis after TAVI with self-expandable prosthesis is present in 9–28% of patients depending on the definition of haemolysis. The presence of haemolysis is associated with moderate/severe paravalvular aortic regurgitation but not with post-TAVI aortic valve area. Haemolysis is mild with no impact on prognosis.

Impact of device landing zone calcification patterns on paravalvular regurgitation after transcatheter aortic valve replacement with different next-generation devices

ObjectiveResidual paravalvular regurgitation (PVR) has been associated to adverse outcomes after transcatheter aortic valve replacement (TAVR). This study sought to evaluate the impact of device landing zone (DLZ) calcification on...

Long-term follow-up of patients with contained annulus ruptures after TAVI: the EuropeaN COntained RupturE (ENCORE) registry.

The purpose of this registry was to determine the long-term outcomes in patients with asymptomatic contained annulus rupture (CR) as a rare complication of transcatheter aortic valve implantation (TAVI). The ENCORE registry is a multicentre registry (six centres across Europe) of patients with CR diagnosed on post-TAVI computed tomography angiography (CTA) or transoesophageal echocardiography (TEE). A total of 21 patients (mean age 81.9±4.1 years, 81% balloon-expandable TAVI prostheses) were diagnosed with CR (mean size of lesions was 15.3±6.9 × 8.5±3.3 × 8.5±2.3 mm). Seventeen were diagnosed among a total of 1,602 consecutive routine post-TAVI CTA (incidence 1.1%), two in TEE and two in post-TAVI CTA (each conducted due to suspicion of peri-interventional complications). During a mean follow-up of 2.3±1.7 years (cumulative 48.6 patient-years), nine patients (43%) died from non-cardiac causes. None of the patients exhibited symptoms or underwent interventional treatment related to the CR; no sudden cardiac death occurred. A follow-up CTA, performed in eleven patients 240±176 days post TAVI, revealed stable CR findings in seven, regression in one, and remission in three patients. The results of our international multicentre registry demonstrate favourable long-term outcomes of CR after TAVI supporting a watch-and-wait strategy in these patients.

Annular versus supra-annular sizing for TAVI in bicuspid aortic valve stenosis

We sought to compare annular versus supra-annular sizing for transcatheter aortic valve implantation (TAVI) in patients with a bicuspid aortic valve (BAV). In this retrospective single-centre analysis, we measured the aortic annulus (Ann) and intercommissural distance (ICD) on multidetector computed tomography scans in 217 BAV patients. With annular sizing being the default method for prosthesis size selection in all cases, we determined clinically relevant sizing errors and assessed the hypothetical impact of supra-annular sizing. Overall there was no significant difference between ICD and Ann (25.1 [23.5; 27.3] vs. 25.4 [23.6; 27.1] mm; p=0.24); intra-individually, ICD was similar to Ann in 26.7%, smaller in 40.1%, and larger in 33.2%. Annular sizing was appropriate in 96.3%, oversized in 0.5%, and undersized in 3.2% of cases. Supra-annular sizing would have resulted in a divergent size selection in 38.7% (smaller: 17.5%, larger: 19.8%, ICD out of range for TAVI prostheses: 1.4%) with potential improvement in a few cases with annular sizing errors, but potential worsening due to improper size selection in a much larger proportion of patients. Annular sizing for TAVI in BAV is feasible and safe. The added value of supra-annular sizing is questionable.

Do CTA measurements of annular diameter, perimeter and area result in different TAVI prosthesis sizes?

Incorrect prosthesis size has direct impact on patient outcome after transcatheter aortic valve implantation (TAVI) procedure. Currently, annular diameter, area or perimeter may be used for prosthesis size selection. The aim was to evaluate whether the use different annular dimensions would result in the selection of different prosthesis sizes, when assessed in the same TAVI-candidate during the same phase of a cardiac cycle. Fifty consecutive TAVI-candidates underwent retrospectively ECG-gated computed tomography angiography (CTA). Aortic root dimensions were assessed in the 20% phase of the R–R interval. Annular short diameter, perimeter and area were used to select the prosthesis size, based on the industry recommendations for a self-expandable (Medtronic CoreValve; MCV) and balloon-expandable (Edwards Sapien XT Valve; ESV) valve. Complete agreement on selected prosthesis size amongst all three annular dimensions was observed in 62% (31/50; ESV) and 30% (15/50; MCV). Short aortic annulus measurement resulted in a smaller prosthesis size in 20% (10/50; ESV) and in 60% of cases (30/50; MCV) compared to the size suggested by both annular perimeter and area. In 18% (9/50; ESV) and 10% of cases (5/50; MCV) a larger prosthesis would have been selected based on annular perimeter compared to annular diameter and area. Prosthesis size derived from area was always in agreement with at least one other parameter in all cases. Aortic annulus area appears to be the most robust parameter for TAVI-prosthesis size selection, regardless of the specific prosthesis size. Short aortic annulus diameter may underestimate the prosthesis size, while use of annular perimeter may lead to size overestimation in some cases.

Pacemaker implantation rate after transcatheter aortic valve implantation with early and new-generation devices: a systematic review.

The incidence of new-onset conduction abnormalities requiring permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) with new-generation prostheses remains debated. This systematic review analyses the incidence of PPI after TAVI with new-generation devices and evaluates the electrical, anatomical, and procedural factors associated with PPI. In addition, the incidence of PPI after TAVI with early generation prostheses was reviewed for comparison. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist, this systematic review screened original articles published between October 2010 and October 2017, reporting on the incidence of PPI after implantation of early and new-generation TAVI prostheses. Of the 1406 original articles identified in the first search for new-generation TAVI devices, 348 articles were examined for full text, and finally, 40 studies (n = 17139) were included. The incidence of a PPI after the use of a new-generation TAVI prosthesis ranged between 2.3% and 36.1%. For balloon-expandable prostheses, the PPI rate remained low when using an early generation SAPIEN device (ranging between 2.3% and 28.2%), and with the new-generation SAPIEN 3 device, the PPI rate was between 4.0% and 24.0%. For self-expandable prostheses, the PPI rates were higher with the early generation CoreValve device (16.3-37.7%), and despite a reduction in PPI rates with the new Evolut R, the rates remained relatively higher (14.7-26.7%). When dividing the studies according to the highest (>26.0%) and the lowest (<12.1%) quintile of PPI rate, patients within the highest quintile were more frequently women when compared with the lowest quintile group (50.9% vs. 46.3%, P < 0.001). Pre-existent conduction abnormalities (electrical factor), calcification of the left ventricular outflow tract (anatomical factor), and balloon valvuloplasty and depth of implantation (procedural factors) were associated with increased risk of PPI. The rate of PPI after TAVI with new-generation devices is highly variable. Specific recommendations for implantation of each prosthesis, taking into consideration the presence of pre-existent conduction abnormalities and anatomical factors, may be needed to reduce the risk of PPI.

A cost-utility analysis of transcatheter versus surgical aortic valve replacement for the treatment of aortic stenosis in the population with intermediate surgical risk

ObjectiveAlthough transcatheter aortic valve implantation has been shown to be noninferior to surgical aortic valve replacement in patients with severe aortic stenosis at intermediate surgical risk, the cost-effectiveness of this strategy in this population is unknown. Our objective was to conduct a cost-utility analysis comparing transcatheter aortic valve implantation with surgical aortic valve replacement in the population with intermediate risk severe aortic stenosis. MethodsA fully probabilistic Markov model with 30-day cycles was constructed from the Canadian third-party payer's perspective to estimate the difference in cost and effectiveness (measured as quality-adjusted life years) of transcatheter aortic valve implantation versus surgical aortic valve replacement for intermediate-risk patients over a lifetime time horizon, discounted at 1.5% per annum. Clinical trial data from The Placement of Aortic Transcatheter Valve 2 informed the efficacy inputs. Costs (adjusted to 2016 Canadian dollars) were obtained from the Canadian Institute of Health Information and the Ontario Schedule of Benefits. Incremental cost-effectiveness ratios were calculated. ResultsIn the base-case analysis, total lifetime costs for transcatheter aortic valve implantation were $10,548 higher than surgical aortic valve replacement but added 0.23 quality-adjusted life years, for an incremental cost-effectiveness ratio of $46,083/quality-adjusted life-years gained. Deterministic 1-way analyses showed that the incremental cost-effectiveness ratio was sensitive to rates of complications and cost of the transcatheter aortic valve implantation prosthesis. There was moderate-to-high parameter uncertainty; transcatheter aortic valve implantation was the preferred option in only 52.7% and 55.4% of the simulations at a $50,000 and $100,000 per quality-adjusted life years willingness-to-pay thresholds, respectively. ConclusionsOn the basis of current evidence, transcatheter aortic valve implantation may be cost-effective for the treatment of severe aortic stenosis in patients with intermediate surgical risk. There remains moderate-to-high uncertainty surrounding the base-case incremental cost-effectiveness ratio.

Influence of the Quantity of Aortic Valve Calcium on the Agreement Between Automated 3-Dimensional Transesophageal Echocardiography and Multidetector Row Computed Tomography for Aortic Annulus Sizing

Accurate aortic annulus sizing is key for selection of appropriate transcatheter aortic valve implantation (TAVI) prosthesis size. The present study compared novel automated 3-dimensional (3D) transesophageal echocardiography (TEE) software and multidetector row computed tomography (MDCT) for aortic annulus sizing and investigated the influence of the quantity of aortic valve calcium (AVC) on the selection of TAVI prosthesis size. A total of 83 patients with severe aortic stenosis undergoing TAVI were evaluated. Maximal and minimal aortic annulus diameter, perimeter, and area were measured. AVC was assessed with computed tomography. The low and high AVC burden groups were defined according to the median AVC score. Overall, 3D TEE measurements slightly underestimated the aortic annulus dimensions as compared with MDCT (mean differences between maximum, minimum diameter, perimeter, and area: -1.7 mm, 0.5 mm, -2.7 mm, and -13 mm2, respectively). The agreement between 3D TEE and MDCT on aortic annulus dimensions was superior among patients with low AVC burden (<3,025 arbitrary units) compared with patients with high AVC burden (≥3,025 arbitrary units). The interobserver variability was excellent for both methods. 3D TEE and MDCT led to the same prosthesis size selection in 88%, 95%, and 81% of patients in the total population, the low, and the high AVC burden group, respectively. In conclusion, the novel automated 3D TEE imaging software allows accurate and highly reproducible measurements of the aortic annulus dimensions and shows excellent agreement with MDCT to determine the TAVI prosthesis size, particularly in patients with low AVC burden.

OBSERVANT II: OBservational Study of Effectiveness of transcatheter aortic valve implantation with new geneRation deVices for severe Aortic steNosis Treatment. Study protocol

The rapid spread of transcatheter aortic valve implantation (TAVI) for the treatment of severe symptomatic aortic stenosis in the last decade in Italy has led to a gradually increasing use of TAVI procedures also in patients potentially eligible for aortic valve replacement (AVR). For this subset of patients, the OBSERVANT study (2011-2012) evaluated the short- and medium term outcome of TAVI vs AVR, at least for the first generations of TAVI devices, but failed to gather information on all the technological innovations occurred in recent years. The launch of a phase II of the study will allow to recruit a new series of TAVI, with different risk profiles compared with the historical OBSERVANT TAVI cohort, in order to assess whether and how much the use of new-generation devices mitigate the differences in outcomes recorded in the OBSERVANT study. OBSERVANT II is an observational multicenter, prospective, cohort study collecting data on patients with severe symptomatic aortic stenosis undergoing TAVI in Italian hospitals since December 15, 2016, for at least 12 months. For each patient, data on demographic characteristics, health status, type of intervention and presence of comorbidities will be collected. Mortality and incidence of in-hospital major adverse cardiac and cerebrovascular events (MACCE) within 36 months of intervention will be the primary adverse outcome. Secondary outcomes will include 30-day mortality and the incidence of MACCE at 12 and 24 months. The statistical hypotheses were formulated considering the results from the OBSERVANT study. Testing these hypotheses will require the recruitment of at least 823 new TAVI. The risk/propensity-adjustment techniques will be used to comparatively evaluate the effectiveness of TAVI vs AVR. Safety and efficacy profiles of the new-generation TAVI prosthesis; comparative effectiveness of the new TAVI prosthesis as compared to TAVI procedures of the OBSERVANT historical cohort; comparative effectiveness of the new TAVI prosthesis as compared to AVR procedures of the OBSERVANT historical cohort. The results of OBSERVANT II will provide information on the effectiveness of TAVI employing new-generation devices and will be a valuable support to give professionals and policy makers evidence-based results useful for decision-making processes.

Trans-catheter aortic valve implantation: Contemporary practice and the future.

With increasing life expectancy, the epidemic of valvular heart disease, especially aortic stenosis (AS), is becoming more prevalent. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative therapy for patients with significant aortic valve disease. It offers a less invasive procedure in comparison to surgical aortic valve replacement (sAVR) and an attractive substitute from the patient's perspective. The evidence for TAVI in inoperable and high risk surgical patients is now established and in the intermediate risk group has been accumulating rapidly and is looking favourable for TAVI. However, the full 'TAVI story' is still unfolding. Technological advances in devices and delivery systems are evolving with the aim to improve the function and durability of TAVI and to simplify the procedure while enhancing safety. The incidence of vascular injury and pacemaker requirement post TAVI remains an issue and further development in this regard is therefore of utmost importance, particularly as lower risk and potentially younger patients are treated. Moreover, the evidence concerning long-term durability of the TAVI prostheses continues to accumulate. Whilst TAVI is proving to be an invaluable tool for inoperable and high risk patients, more trial evidence is needed before it encompases lower risk populations and moreover, its use as a first line treatment worldwide in most healthcare systems is limited by the costs associated with the prosthesis.

Transcatheter aortic valve implantation for bicuspid aortic valve stenosis: Acute and intermediate-term outcomes in a high volume institution

Background: We report our experience with transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve (BAV) stenosis.Methods: Perioperative and intermediate-term follow-up data were retrospectively analysed. All procedures were performed within the premises of an experienced high-volume TAVI centre.Results: Tirty-three consecutive BAV patients (age 55 to 87 years) underwent TAVI. Mean logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 23,2 ± 19,3. Transapical Edwards Sapien® valve was implanted in the majority of patients (87.9 %). Nine patients (27.3 %) required post-ballooning of the implanted valve for moderate to severe paravalvular leak, 3 patients (9 %) required a second valve implantation for persistent severe paravalvular leak, and 2 (6 %) required conversion to conventional surgery. Post-operative mild aortic regurgitation (AR) was presented in 12 patients (36.4%) and AR = 2 in 3 %. No AR &gt; 2 was observed. Te device success rate according to the valve academic research consortium (VARC) criteria was 82 %. Similar BAV anatomy, calcium distribution, type and size of implanted valve were noticed in patients with and without residual AR. Tere was no thirty-day mortality. Two-year estimated survival was 70 % (CI: 52.7–93.1) and was similar in patients with and without post-procedural residual paravalvular leak.Conclusions: TAVI in BAV stenosis is feasible but, even in experienced centres, is technically more challenging and is associated with a higher rate of post-dilatation, re-valving, and conversion to conventional surgery. Results should be re-tested in light of the recent introduction of second-generation TAVI prostheses.

Subacute Subclinical Brain Infarctions after Transcatheter Aortic Valve Implantation Negatively Impact Cognitive Function in Long-Term Follow-Up.

AimsTo date every post-procedural cerebrovascular embolic event (CVE) is dreaded for its potential to accelerate cognitive decline after transcatheter aortic valve implantation (TAVI). This study differentiates the impact of acute (procedural) and post-acute cerebrovascular embolic events (CVEs) on cognitive performance.MethodsMagnetic resonance imaging (MRI) before, early and late after TAVI was performed to quantify embolic burden. Quantification of diffusion- and T1-weighted lesions, as well as white-matter and total brain volumes, as well as cognitive function testing (MMSE) were assessed in 28 patients with a medium follow-up period of 34 months.ResultsProcedural diffusion-weighted lesions were observed in 17 patients (61%), but demonstrated locoregional remnants only in a minority of patients in long-term follow-up (6.5%). Acute CVEs did not impact the trajectory of late silent brain infarctions (SBI), white-matter hyperintensities, and cerebral atrophy. Functionally, early CVEs did not affect cognitive function. In contrast, patients with “new” SBIs after TAVI had a trend to cognitive deterioration in long-term follow-up (“new”SBI: MMSE -1.4 / no “new”SBI: MMSE +1.5, p = 0.067). Interestingly, only a fraction of these “new” SBIs evolved from procedural CVEs (22.2%).ConclusionsAquired SBIs after TAVI, but not DW-CVE per se are associated with functional impairment long-term after TAVI. In the context of subacute thrombosis seen in TAVI prostheses, these findings set the stage for tailored stroke prevention and comprehensive surrogate endpoint definitions in neuroprotective trials.

Redo TAVI: initial experience at two German centres.

The aim of this study was to assess the feasibility and early outcomes of transcatheter aortic valve implantation (TAVI) in dysfunctional TAVI prostheses (redo TAVI). Nineteen redo TAVI procedures were performed between October 2011 and November 2015 at two German centres. Mean age was 78 years, 13 (68%) were male, and the mean logistic EuroSCORE was 32%. Median time elapsed since index TAVI was 644 days (interquartile range 191-1,831). Failure mode of the index TAVI prosthesis was regurgitation (AR) in 16 patients (n=12 paravalvular AR, n=3 combined paravalvular/valvular AR, n=1 valvular AR) and stenosis in three patients. Device success was achieved in 89% (17/19). Median invasive post-interventional transprosthetic gradient was 3.0 mmHg. No severe prosthesis-patient mismatch (PPM) was observed. At one year, mean pressure gradient was 9±1.2 mmHg and no relevant PPM was documented in 90% of the cases. All-cause mortality at 30 days and one year was 11% and 33% (6/18, five non-cardiac deaths), respectively. Mean follow-up time was 404 days. Redo TAVI appears to be feasible. Paravalvular regurgitation was the most common indication for a redo procedure. Rates of device success were high with low post-interventional gradients and no severe PPM. Good functional status of the prosthesis was maintained after 12 months, but mortality rates were high in this small comorbid patient population.

TAVI for aortic regurgitation – India's first case with Corevalve Evolut R

Transcatheter Aortic Valve Implantation (TAVI) is a well-described treatment for symptomatic calcific severe aortic stenosis. However, TAVI technology is being increasingly used around the world to treat selected cases of severe aortic regurgitation (AR). One of the main limitations of using TAVI technology for AR is the lack of calcification, which is common in such cases. This makes anchoring of a TAVI prosthesis to the aortic annulus difficult and risks displacement or embolization. However, with the availability of recapturable and repositionable TAVI technologies, these limitations have been overcome to a large extent. This is the first Corevalve Evolut R device that was used in India and the first TAVI to treat AR in India.

Long-Term Outcomes After Transcatheter Aortic Valve Implantation from a Single High-Volume Center (The Milan Experience)

Transcatheter aortic valve implantation (TAVI) is now the treatment of choice for patients with symptomatic aortic stenosis who are inoperable or with high surgical risk. Data with regards to contemporary clinical practice and long-term outcomes are sparse. To evaluate temporal changes in TAVI practice and explore procedural and long-term clinical outcomes of patients in a contemporary "real-world" population, outcomes of 829 patients treated from November 2007 to May 2015, at the San Raffaele Scientific Institute, Milan, Italy, were retrospectively analyzed. Median follow-up was 568 days, with the longest follow-up of 2,677 days. Overall inhospital mortality was 3.5%. During the study period, there was a trend toward treating younger, lower risk patients. Overall mortality rates were 3.5% (30 days), 14% (1 year), 22% (2 years), 29% (3 years), 37% (4 years), 47% (5 years), 53% (6 years), and 72% (7 years). The survival probability at 5 years was significantly higher in patients treated through the transfemoral (TF) route compared to other vascular access sites (log rank p <0.001). Non-TF vascular access and residual paravalvular leak ≥2 (after TAVI) were identified as independent predictors for both all-cause and cardiovascular mortality. No patient required further aortic valve intervention for TAVI prosthesis degeneration. In conclusion, there is a trend toward treating younger, lower-risk patients. Non-TF vascular access approach and ≥2 PVL after TAVI were identified as independent predictors for both overall and cardiovascular mortality with no cases of prosthesis degeneration suggesting acceptable durability.

Does the aortic annulus undergo conformational change throughout the cardiac cycle? A systematic review

Accurate annular sizing in transcatheter aortic valve implantation (TAVI) planning is essential. It is now widely recognized that the annulus is an oval structure in most patients, but it remains unclear if the annulus undergoes change in size and shape during the cardiac cycle that may impact prosthesis size selection. Our aim was to assess whether the aortic annulus undergoes dynamic conformational change during the cardiac cycle and to evaluate possible implications for prosthesis size selection. We performed a systematic search in PubMed and Embase databases and reviewed all available literature on aortic annulus measurements in at least two cardiac phases. Twenty-nine articles published from 2001 to 2014 were included. In total, 2021 subjects with and without aortic stenosis were evaluated with a mean age ranging from 11 ± 3.6 to 84.9 ± 7.2 years. Two- and three-dimensional echocardiography was performed in six studies each, magnetic resonance imaging was used in one and computed tomography in 17 studies. In general, the aortic annulus was more circular in systole and predominantly oval in diastole. Whereas the annular long-axis diameter showed insignificant change throughout the cycle, the short-axis diameter, area, and perimeter were significantly larger in systole compared with diastole. Hence, the aortic annulus does undergo dynamic changes during the cardiac cycle. In patients with large conformational changes, diastolic compared with systolic measurements can result in undersizing TAVI prostheses. Due to the complex annular anatomy and dynamic change, three-dimensional assessment in multiple phases has utmost importance in TAVI planning to improve prosthesis sizing.

Investigation of the tubular leaflet geometry of an aortic heart valve prosthesis by finite-element analysis

This paper presents the analysis of relationships between geometrical parameters of the tubular leaflet apparatus and its functional characteristics. In addition, the degree of the influence of deformation of different zones of leaflets on its ability to perform its function is evaluated in this work. The outcomes of this study could be helpful in developing new models of the transcatheter prosthetic heart valves leaflet apparatus or analyzing existing in-clinical transcatheter aortic valve implantation prostheses.

Multislice computed tomography-based prediction of the implantation plane in transcatheter aortic valve implantation: determination of the line of perpendicularity and the implanter's views.

We demonstrate a multislice computed tomography (MSCT)-based method to calculate the prediction of the so-called 'line of perpendicularity' (LOP) and the 'implanter's views' (IVs) for transcatheter aortic valve implantation (TAVI) procedures. The LOP represents all possible angiographic angulations that result in an orthogonal view to the aortic annulus plane. The IVs allow visual confirmation of correct implantation planes, and are crucial for the commissural aligned implantation of second-generation TAVI prostheses. The LOP and IVs of 335 concomitant patients were prospectively analysed using multiple plane reconstruction (MPR) of the patient's MSCT scans. Exclusion criteria were bicuspid valves (n = 18) and valve-in-valve TAVI (n = 15). In the MPRs, the aortic cusps' lowest points were marked. With the marker's three-dimensional coordinates, the graph of the LOP with the IVs was calculated and plotted using vector mathematics. In the last 244 cases, the IV with the right coronary cusp in front was chosen for the first aortic root angiogram of the TAVI procedure. The finally used angulation was confirmed by aortic angiogram prior to the valve implantation. Solid angle differences that show the combined left anterior oblique/right anterior oblique and cranio/caudal movement of the C-arm allow quantification of corrections as well as demonstrate interindividual variations. There is a broad interindividual variation of the aortic valve's topology with solid angle variations of up to 74°. The shape of the LOPs is extremely varying, especially regarding the slope of the curve that indicates differences in valve orientations. Among the 244 patients for whom we used the prediction for the procedure, the first angiogram was considered perfect for implantation without further corrections in 97% (n = 237) of them. In case of the 7 patients with subsequent corrections, the mean solid angle between the prediction and the final angiogram prior to implantation was 6.2° (±5°); the largest correction was 14°. Prediction of the implantation plane by analysing the patient's MSCT is highly reliable in achieving an adequate view of the aortic annulus in TAVI. The analysis of LOPs showed the large interindividual differences that permit using a standard implantation plane. Therefore, we strongly recommend determining the LOP and IVs during the patient's screening process in each single TAVI case.

The Current Situation and the Future of Emergent Cardiac Surgery in TAVI.

Transcatheter aortic valve implantation (TAVI) has become a beneficial treatment for patients with aortic valve stenosis deemed at high or even prohibitive risk for open surgery. The risk for severe complications is low (ranging between 0.2 % and 1.0 %); nevertheless, in approximately 1 % of patients emergency cardiac surgery (ECS) is required during TAVI. Aortic injury, embolization of the TAVI prosthesis, and myocardial injury are among the most frequent complications necessitating ECS. Mortality rates of ECS during TAVI are high, ranging between 45 % and 67 %, owing to the comorbid and fragile health status of TAVI patients. Therefore, avoidance of complications appears to be of utmost importance to improve outcomes. This review analysis the current literature in terms of incidence, causes, and outcomes of ECS during TAVI.