Optimization of Enzymatic and Chemical Decellularization of Native Porcine Heart Valves for the Generation of Decellularized Xenografts.

One of the most important medical interventions for individuals with heart valvular disease is heart valve replacement, which is not without substantial challenges, particularly for pediatric patients. Due to their biological properties and biocompatibility, natural tissue-originated scaffolds derived from human or animal sources are one type of scaffold that is widely used in tissue engineering. However, they are known for their high potential for immunogenicity. Being free of cells and genetic material, decellularized xenografts, consequently, have low immunogenicity and, thus, are expected to be tolerated by the recipient's immune system. The scaffold ultrastructure and ECM composition can be affected by cell removal agents. Therefore, applying an appropriate method that preserves intact the structure of the ECM plays a critical role in the final result. So far, there has not been an effective decellularization technique that preserves the integrity of the heart valve's ultrastructure while securing the least amount of genetic material left. This study demonstrates a new protocol with untraceable cells and residual DNA, thereby maximally reducing any chance of immunogenicity. The mechanical and biochemical properties of the ECM resemble those of native heart valves. Results from this study strongly indicate that different critical factors, such as ionic detergent omission, the substitution of Triton X-100 with Tergitol, and using a lower concentration of trypsin and a higher concentration of DNase and RNase, play a significant role in maintaining intact the ultrastructure and function of the ECM.

Devastating fungal endocarditis involving ascending aorta in a patient with a history of aortic valve replacement: a case report.

BACKGROUND: Fungal endocarditis is a rare but serious condition associated with high mortality rates. Various predisposing factors contribute to its occurrence, such as underlying cardiac abnormalities, cardiac surgeries, prosthetic cardiac devices, and central venous catheters. Diagnosing fungal endocarditis, particularly Aspergillus, poses challenges, often complicated by negative blood cultures. CASE PRESENTATION: This report details a case of extensive ascending aorta involvement in Aspergillus endocarditis (AE) in a 24-year-old man with a history of bioprosthesis aortic valve replacement (AVR). Three months post-AVR, he presented with pericardial effusion and aortic rupture, leading to a redo biological valved conduit aortic root replacement (Bentall surgery). Despite the intervention, the tubular graft exhibited extensive Aspergillus involvement, resulting in graft disruption and significant peri-aortic infection. A second redo procedure involving aortic homograft root replacement was performed. Unfortunately, the patient succumbed two days after the surgery. CONCLUSION: A combined approach of medical and surgical therapies is recommended to manage fungal endocarditis. Despite efforts, the mortality rate associated with Aspergillus endocarditis remains unacceptably high, with no significant difference observed between combination therapy and antifungal treatment alone. Further research is essential to explore novel therapeutic strategies and improve outcomes for patients with this challenging condition.

Perceval-S over time. Clinical outcomes after ten years of usage.

BACKGROUND: Perceval-S has become a reliable and commonly used option in surgical aortic valve replacement (AVR) since its first implantation in humans 15 years ago. Despite the fact that this aortic valve has been proven efficient enough in the short and mid-term period, there is still lack of evidence for the long-term outcomes. MATERIALS AND METHODS: This is an observational retrospective study in a high-volume cardiovascular center. Pertinent data were collected for all the patients in whom Perceval-S was implanted from 2013 to 2020. RESULTS: The total number of patients was 205 with a mean age 76.4 years. Mean survival time was 5.5 years (SE = 0.26). The overall survival probability of patients undergoing aortic valve replacement with Perceval-S at 6 months was 91.0% (Standard Error SE = 2.0%), at one year 88.4% (SE = 2.3%) and at 5-years 64.8% (SE = 4.4%). A detrimental cardiac event leading to death was the probable cause of death in 35 patients (55.6%). The initiation of Transcatheter Aortic Valve Replacement (TAVR) program in our center in 2017 was associated with a decline in the number of very high-risk patients treated with sutureless bioprosthesis. This fact is demonstrated by the significant shift towards lower surgical risk cases, as median Euroscore II was reduced from 5,550 in 2016 to 3,390 in 2020. Mini sternotomy was implemented in 79,5% of cases favoring less invasive approach. Low incidence of reinterventions, patient prosthesis mismatch and structural valve degeneration was detected. CONCLUSIONS: The survival rate after aortic valve replacement with implantation of Perceval-S is satisfactory in the long-term follow-up. Cases of bioprosthesis dysfunction were limited. Mini sternotomy was used in the majority of cases. TAVR initiation program impacted on the proportion of patients treated with Perceval-S with reduction of high-risk patients submitted to surgery.

Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome.

OBJECTIVES: Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes. METHODS: One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level). RESULTS: Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels. CONCLUSION: Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Continuous or interrupted pledgeted suture technique in stented bioprosthetic aortic valve replacement: a comparison of in-hospital outcomes.

BACKGROUND: There is ambiguity in the literature regarding the continuous suture technique (CST) for aortic valve replacement (AVR). At our center, there has been a gradual shift towards CST over the interrupted pledgeted technique (IPT). This study aims at comparing outcomes for both techniques. METHODS: We performed a retrospective analysis of a single-center study of patients undergoing AVR between January 2011 and July 2020. Patients were divided into two groups: Continuous suture technique and interrupted pledget-reinforced sutures. The pre-operative and In-hospital clinical characteristics and echocardiographic hemodynamics (i.e. transvalvular gradients and paravalvular leakage) were compared between CST and IPT. RESULTS: We compared 791 patients with CST to 568 patients with IPT (median age: 73 and 74 years, respectively, p = 0.02). In CST there were 35% concomitant procedure vs. 31% in IPT (p = 0.16). Early mortality was 3.2% in CST versus 4.8% in IPT (p = 0.15), and a second cross-clamp due to a paravalvular-leak in 0.5% vs. 1.2%, respectively (p = 0.22). The CST was not associated with new-onset conduction-blocks mandating pacemaker implants(OR 1.07, 95% CI 0.54-2.14; P = 0.85). The postoperative gradients on echocardiography were lower in CST compared to IPT, especially in smaller annuli (peak gradients: 15.7mmHg vs. 20.5mmHg, in valve size < 23 mm, p < 0.001). CONCLUSIONS: The continuous suture technique was associated with lower postoperative gradients and shorter cross-clamp time compared to interrupted pledgeted technique. Differences in paravalvular leaks were non-significant, although slightly less in the continuous suture technique. There were no further differences in valve-related complications. Hence, continues suture technique is safe, with better hemodynamics compared to the interrupted pledgeted technique. This may be of clinical importance, especially in smaller size annular size.

Successful valve-in-valve transcatheter intervention to treat severe stenosis of a 38-year-old tricuspid bioprosthesis.

A 60-year-old man presented with breathlessness. Nearly four decades previously, he had required three operations for Staphylococcus aureus infective endocarditis of the tricuspid valve and had received a bioprosthetic valve. He had critical tricuspid bioprosthesis stenosis which was treated successfully by valve-in-valve transcatheter tricuspid valve replacement using a balloon-expandable transcatheter heart valve. One year after intervention, the patient is well with no tricuspid valve stenosis or regurgitation.

[Sudden Chest Pain due to Early Bioprosthetic Valve Dysfunction:Report of a Case].

We report a case of bioprosthetic valve dysfunction and acute aortic valve regurgitation. The case was a 75-year-old female who had sudden onset chest pain. ST-segment depression in several leads on electrocardiogram( ECG) suggested acute coronary syndrome. Coronary angiography showed no significant stenosis in coronary arteries. Transesophageal echocardiography revealed severe aortic regurgitation, suggesting that angina was caused by myocardial ischemia associated with acute aortic regurgitation. She was diagnosed as having bioprosthetic valve dysfunction, and underwent redo aortic valve replacement. One leaflet of the bioprosthetic valve was torn along the stent post and caused bioprosthetic valve dysfunction. Failed bioprosthetic valve was removed and replaced by a mechanical valve.

Coronary Cannulation Following TAVR Using Self-Expanding Devices With Commissural Alignment: The RE-ACCESS 2 Study.

BACKGROUND: Coronary re-engagement after transcatheter aortic valve replacement (TAVR) using self-expanding transcatheter heart valves (THVs) systematically implanted using commissural alignment (CA) techniques has been poorly investigated. OBJECTIVES: The aim of this study was to evaluate unsuccessful coronary cannulation, and its predictors, after TAVR using self-expanding devices implanted using CA techniques. METHODS: RE-ACCESS 2 (Reobtain Coronary Ostia Cannulation Beyond Transcatheter Aortic Valve Stent 2) was an investigator-driven, single-center, prospective study that enrolled consecutive TAVR patients receiving Evolut and ACURATE THVs implanted using CA techniques. The primary endpoint was unsuccessful coronary cannulation after TAVR. The secondary endpoint was the identification of postprocedural predictors of unfeasible, selective coronary ostia re-engagement on computed tomographic angiography performed after TAVR. RESULTS: Among 127 patients enrolled from September 2021 to December 2022, 7 (5.5%) had unsuccessful coronary cannulation after TAVR, and 6 of them received Evolut THVs (7.5% vs 2.3%; P = 0.26). Failure of left coronary artery cannulation was similar between Evolut and ACURATE THVs (2.5% vs 2.1%; P = 1.00), whereas that of right coronary artery cannulation was prevalent in the Evolut group (6.3% vs 0.0%; P = 0.16). Coronary overlap was associated with the inability to selectively cannulate the right coronary artery (OR: 5.6; 95% CI: 1.2-25.8; P = 0.03), but not in ACURATE recipients (P = 0.39). Severe misalignment of Evolut THVs was associated with the inability to selectively cannulate both coronary arteries (OR: 24.7; 95% CI: 1.9-312.9; P = 0.01). CONCLUSIONS: Unsuccessful coronary cannulation after TAVR using self-expanding THVs implanted using CA techniques was reported in 5.5% of cases, with the majority involving the Evolut THV. Commissural misalignment affected coronary cannulation after TAVR mostly in Evolut recipients.

Comparison of two self-expanding transcatheter heart valves for degenerated surgical bioprostheses: the AVENGER multicentre registry.

BACKGROUND: There is a lack of comparative data on transcatheter aortic valve implantation (TAVI) in degenerated surgical prostheses (valve-in-valve [ViV]). AIMS: We sought to compare outcomes of using two self-expanding transcatheter heart valve (THV) systems for ViV. METHODS: In this retrospective multicentre registry, we included consecutive patients undergoing transfemoral ViV using either the ACURATE neo/neo2 (ACURATE group) or the Evolut R/PRO/PRO+ (EVOLUT group). The primary outcome measure was technical success according to Valve Academic Research Consortium (VARC)-3. Secondary outcomes were 30-day all-cause mortality, device success (VARC-3), coronary obstruction (CO) requiring intervention, rates of severe prosthesis-patient mismatch (PPM), and aortic regurgitation (AR) ≥moderate. Comparisons were made after 1:1 propensity score matching. RESULTS: The study cohort comprised 835 patients from 20 centres (ACURATE n=251; EVOLUT n=584). In the matched cohort (n=468), technical success (ACURATE 92.7% vs EVOLUT 88.9%; p=0.20) and device success (69.7% vs 73.9%; p=0.36) as well as 30-day mortality (2.8% vs 1.6%; p=0.392) were similar between the two groups. The mean gradients and rates of severe PPM, AR ≥moderate, or CO did not differ between the groups. Technical and device success were higher for the ACURATE platform among patients with a true inner diameter (ID) >19 mm, whereas a true ID ≤19 mm was associated with higher device success - but not technical success - among Evolut recipients. CONCLUSIONS: ViV TAVI using either ACURATE or Evolut THVs showed similar procedural outcomes. However, a true ID >19 mm was associated with higher device success among ACURATE recipients, whereas in patients with a true ID ≤19 mm, device success was higher when using Evolut.

Unusual cause of severe transvalvular eccentric jet AR: early structure valve deterioration of Trifecta valves by flail leaflet undergoing valve-in-valve transcatheter aortic valve replacement.

The Trifecta tissue valve (Abbott, Illinois, USA) is an externally mounted bovine pericardial aortic valve (AV) prosthesis with adequate haemodynamic performance and better early results than another option. However, concerns have been raised about its durability. Recently, reports have emerged about an increased incidence of early structural valve failure after Trifecta implantation, where leaflet tear(s) with dehiscence along the stent post was the primary mode of early failure. In this article, we present the case of a patient in her 70s, 7 years after AV replacement with a Trifecta valve, who developed progressive dyspnoea. Physical examination revealed signs of chronic severe aortic regurgitation (AR). The initial transthoracic echocardiogram showed severe transvalvular AR, but the aetiology could not be determined. Cardiac computed tomography (CT) revealed a flail non-coronary cusp of the Trifecta bioprosthetic valve without vegetation. After discussion, we concluded that our patient was suitable for valve-in-valve transcatheter aortic valve replacement (ViV TAVR).

Impact of explanted valve type on aortic valve reoperations: nationwide UK experience.

OBJECTIVES: This nationwide retrospective cohort study assessed the impact of the explanted valve type on reoperative outcomes in aortic valve surgery within the UK over a 23-year period. METHODS: Data were sourced from the National Institute for Cardiovascular Outcomes Research (NICOR) database. All patients undergoing first-time isolated reoperative aortic valve replacement between 1996 and 2019 in the UK were included. Concomitant procedures, homograft implantation or aortic root enlargement were excluded. Propensity score matching was utilized to compare outcomes and risk factors for in-hospital mortality was evaluated through multivariable logistic regression. Final model selection was conducted using Akaike Information Criterion through bootstrapping. The primary end point was in-hospital mortality, and secondary end points included postoperative morbidities. RESULTS: Out of 2371 patients, 24.9% had mechanical and 75% had bioprosthetic valves implanted during the primary procedure. Propensity matched groups of 324 patients each, were compared. In-hospital mortality for mechanical and bioprosthetic valve explants was 7.1% and 5.9%, respectively (P = 0.632). On multivariable logistic regression analysis, valve type was not a risk factor for mortality [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.37-1.05; P = 0.1]. Age (OR 1.03, 95% CI 1.01-1.05; P < 0.05), left ventricular ejection fraction (OR 1.62, 95% CI 1.08-2.42; P < 0.05), creatinine ≥ 200 mg/dl (OR 2.21, 95% CI 1.17-4.04; P < 0.05) and endocarditis (OR 2.66, 95% CI 1.71-4.14; P < 0.05) emerged as risk factors for mortality. CONCLUSIONS: The type of valve initially implanted (mechanical or bioprosthetic) did not determine mortality. Instead, age, left ventricular ejection fraction, renal impairment and endocarditis were significant risk factors for in-hospital mortality.

The Young Investigator Committee of the International Xenotransplantation Association-Perspective of advancements in the field in 2023.

The 2023 IXA conference, hosted in San Diego, CA, brimmed with excitement against the backdrop of recent innovations in both the pre-clinical and clinical realms with several first-in-human applications of xenotransplantation. The theme, "Pigs are flying," alluded to the adage that xenotransplantation would only become a clinical reality "when pigs fly," suggesting a day that might never come. The event witnessed significant attendance, with 600 participants-the highest in the history of an IXA-IPITA joint congress. Among the attendees were members of the Food and Drug Administration (FDA), the National Institutes of Health (NIH), and corporate sponsors deeply engaged in the field. We summarize the latest topics from the congress, ranging from the pros/cons of decedent models of xenotransplantation and genetic engineering of porcine heart valves, solid organs, and cells for clinical translation and their regulatory and ethical landscape.

Perceval sutureless bioprosthesis versus Perimount sutured bioprosthesis for aortic valve replacement in patients with aortic stenosis: a retrospective, propensity-matched study.

BACKGROUND: Rapid-deployment aortic valve replacement (RDAVR) is an alternative to conventional AVR (cAVR) for aortic stenosis. Benefits include a reduction in operative times, facilitation of minimal access surgery and superior haemodynamics compared to conventional valves. However, further evidence is required to inform guidelines, preferably in the form of propensity-matched studies that include mid-term follow-up data. METHODS: This was a single-centre, retrospective, propensity-matched cohort study comparing the Perceval and conventional Perimount Magna Ease valve for short- and mid-term clinical parameters and size-matched mid-term echocardiographic parameters (n = 102 in both groups) from 2014 to 2020. Data were extracted from a nationally managed dataset. RESULTS: There were no demographic differences between the matched groups. The Perceval group had shorter cross-clamp time (Perceval 62 [49-81] minutes; Perimount 79 [63-102] minutes, P < 0.001), shorter bypass time (Perceval 89 [74-114] minutes; Perimount 104 [84-137] minutes, P < 0.001), and more frequent minimally-invasive approaches (Perceval 28%; Perimount 5%, P < 0.001). Size-matched haemodynamics showed initially higher gradients in the Perceval group, but haemodynamics equalised at 12 + months. The Perceval group had a more favourable % change in the left ventricular posterior wall dimension at 2 + years (Perceval - 4.8 ± 18; Perimount 17 ± 2). CONCLUSIONS: The Perceval facilitated shorter operations, which may benefit intermediate-high-risk, elderly patients with comorbidities requiring concomitant procedures. It also facilitated minimally invasive surgery. Size-matched haemodynamic performance was similar at mid-term follow-up, with the Perceval possibly better facilitating regression of left ventricular hypertrophy.

Early and mid-term outcomes after aortic valve replacement using a novel tissue bioprosthesis: a systematic review.

OBJECTIVES: While current data show a clear trend towards the use of bioprosthetic valves during aortic valve replacement (AVR), durability of bioprosthetic valves remains the most important concern. We conducted a 1st systematic review of all available evidence that analysed early and mid-term outcomes after AVR using the Inspiris RESILIA™ bioprosthesis. METHODS: A systematic literature search was performed to identify all relevant studies evaluating early and mid-term outcomes after AVR using the Inspiris RESILIA bioprosthesis and including at least 20 patients with no restriction on the publication date. Subgroup meta-analysis was performed to compare Inspiris RESILIA and PERIMOUNT Magna Ease bioprosthesis and to pool the early postoperative mortality and stroke rates. RESULTS: A total of 416 studies were identified, of which 15 studies met the eligibility criteria. The studies included a total of 3202 patients with an average follow-up of up to 5.3 years. The average age of patients across the studies was 52.2-75.1 years. Isolated AVR was performed in 39.0-86.4% of patients. In-hospital or 30-day postoperative mortality was 0-2.8%. At the mid-term follow-up, freedom from all-cause mortality was up to 85.4%. Among studies with mid-term follow-up, trace/mild paravalvular leak was detected in 0-3.0%, while major paravalvular leak was found only in up to 2.0% of patients. No statistically significant differences in terms of mortality (P = 0.98, odds ratio 1.02, 95% confidence interval 0.36-2.83) and stroke (P = 0.98, odds ratio 1.01, 95% confidence interval 0.38-2.73) between the Inspiris RESILIA bioprosthesis and PERIMOUNT Magna Ease bioprosthesis were observed in the subgroup meta-analysis. CONCLUSIONS: Mid-term data on the safety and haemodynamic performance of the novel aortic bioprosthesis are encouraging. Further comparative studies with other bioprostheses and longer follow-up are still required to endorse durability and safety of the novel bioprosthesis.

Iatrogenic bioprosthetic, self-expandable, transcatheter aortic valve replacement dysfunction after cardiac catheterization.

Bioprosthetic valve dysfunction (BVD) is typically a progressive process related to natural wear of the prosthesis. With acute presentations, possible durability issues or iatrogenic causes need to be considered. Here, we present 2 patients with acute BVD of self-expanding, transcatheter aortic valve replacement post-heart catheterization. The presentations and outcomes, in otherwise normally functioning valves antecedent to the heart catheterizations, raise the question of the increased complexity of coronary access in this valve platform, and whether that or other features provide for greater risk of such events. We believe this to be the first publication of such events and they help to highlight the importance of valve implantation planning, as well as familiarity with the potential complexity of coronary access during heart catheterization.

Outcomes of Valve-in-Valve Transcatheter Aortic Valve Replacement.

Structural valve degeneration is increasingly seen given the higher rates of bioprosthetic heart valve use for surgical and transcatheter aortic valve replacement (TAVR). Valve-in-valve TAVR (VIV-TAVR) is an attractive alternate for patients who are otherwise at high risk for reoperative surgery. We compared patients who underwent VIV-TAVR and native valve TAVR through a retrospective analysis of our institutional transcatheter valve therapy (TVT) database from 2013 to 2022. Patients who underwent either a native valve TAVR or VIV-TAVR were included. VIV-TAVR was defined as TAVR in patients who underwent a previous surgical aortic valve replacement. Kaplan-Meier survival analysis was used to obtain survival estimates. A Cox proportional hazards regression model was used for the multivariable analysis of mortality. A total of 3,532 patients underwent TAVR, of whom 198 (5.6%) underwent VIV-TAVR. Patients in the VIV-TAVR cohort were younger than patients who underwent native valve TAVR (79.5 vs 84 years, p <0.001), with comparable number of women and a higher Society of Thoracic Surgeons risk score (6.28 vs 4.46, p <0.001). The VIV-TAVR cohort had a higher incidence of major vascular complications (2.5% vs 0.8%, p = 0.008) but lower incidence of permanent pacemaker placement (2.5% vs 8.1%, p = 0.004). The incidence of stroke was comparable between the groups (VIV-TAVR 2.5% vs native TAVR 2.4%, p = 0.911). The 30-day readmission rates (VIV-TAVR 7.1% vs native TAVR 9%, p = 0.348), as well as in-hospital (VIV-TAVR 2% vs native TAVR 1.4%, p = 0.46), and overall (VIV-TAVR 26.3% vs native TAVR 30.8%, p = 0.18) mortality at a follow-up of 1.8 years (0.83 to 3.5) were comparable between the groups. The survival estimates were also comparable between the groups (log-rank p = 0.27). On multivariable Cox regression analysis, VIV-TAVR was associated with decreased hazards of death (hazard ratio 0.68 [0.5 to 0.9], p = 0.02). In conclusion, VIV-TAVR is a feasible and safe strategy for high-risk patients with bioprosthetic valve failure. There may be potentially higher short-term morbidity with VIV-TAVR, with no overt impact on survival.

Comparison of a novel self-expanding transcatheter heart valve with two established devices for treatment of degenerated surgical aortic bioprostheses.

AIMS: This study was performed to compare haemodynamic properties of a novel transcatheter heart valve (THV) with two established valve technologies for treatment of failing surgical aortic bioprosthetic valves (SAV). The ALLEGRA THV has been recently described with a proven safety and performance profile. METHODS AND RESULTS: The study was designed as a retrospective, single-centre study investigating 112 patients (77.7 ± 7.1 years, 53.8% female, STS score 6.8 ± 5.8% and logEuroSCORE I 27.4 ± 16.1%) with failing SAV. Patients were treated with the ALLEGRA THV (NVT, n = 24), the CoreValve/EvolutR (MTD, n = 64) or the Edwards Sapien/Sapien XT/Sapien 3 (EDW, n = 24). Adverse events, haemodynamic outcomes and patient safety were analysed according to VARC-3 definitions. Overall procedural success was high (94.6%), even though 58.9% of the treated SAV were classified as small (true inner diameter < 21 mm). After treatment, the mean pressure gradient was significantly reduced (baseline: 33.7 ± 16.5 mmHg, discharge: 18.0 ± 7.1 mmHg), with a corresponding increase in effective orifice area (EOA). The complication rates did not differ in between groups. There was a trend to lower mean transvalvular gradients after implantation of self-expanding THV with supra-annular valve function, despite a higher frequency of smaller SAVs in the NVT and MTD group. Additionally, comparison between NVT and MTD revealed statistically lower transvalvular gradients (NVT 14.9 ± 5.0 mmHg, MTD 18.7 ± 7.5 mmHg, p = 0.0295) in a subgroup analysis. CONCLUSIONS: Valve-in-valve (ViV) treatment of failing SAV with supra-annular design like the ALLEGRA THV resulted in favourable haemodynamic outcomes with similar low clinical event rates and may therefore be an interesting alternative for VIV TAVI.