Portal de Periódicos da CAPES

Redo-Transcatheter Aortic Valve Implantation Using the SAPIEN 3/Ultra Transcatheter Heart Valves—Expert Consensus on Procedural Planning and Techniques

2023; Elsevier BV; Volume: 192; Linguagem: Inglês

10.1016/j.amjcard.2023.01.010

1879-1913

Giuseppe Tarantini, Victoria Delgado, Ole De Backer, Janarthanan Sathananthan, Hendrik Treede, Francesco Saia, Daniel J. Blackman, Radosław Parma,

Cardiac Imaging and Diagnostics

Recent guidelines on valvular heart disease in Europe and the United States have expanded the indications for transcatheter aortic valve implantation (TAVI) to younger patients and those at lower surgical risk with severe symptomatic aortic stenosis. Consequently, the number of TAVI procedures will significantly increase worldwide. Patients with longer life expectancies will outlive their transcatheter heart valves (THVs) and require established treatment strategies for re-intervention. Current data have shown encouraging outcomes, including low mortality, with redo-TAVI; in contrast, surgical explantation of THVs is associated with high mortality. Redo-TAVI, therefore, is likely to be the treatment of choice for THV failure. The expected increase in the number of redo-TAVIs stands in contrast to the current lack of evidence on how this procedure should be planned and performed, including the risks and pitfalls operators need to consider. Preliminary reports stress the importance of preprocedural planning, understanding of THV skirt and leaflet characteristics, and implantation guidelines specific to different THVs. Currently, SAPIEN 3/Ultra is the only THV approved in Europe and the United States for redo-TAVI. Therefore, we gathered a panel of experts in TAVI procedures with the aim of providing operative guidance on redo-TAVI, using the SAPIEN 3/Ultra THV. This consensus article presents a step-by-step approach encompassing clinical, anatomical, and technical aspects in preprocedural planning, procedural techniques, and postprocedural care. In conclusion, the recommendations aim to improve the feasibility, safety, and long-term outcomes of redo-TAVI, including the durability of implanted THVs. Recent guidelines on valvular heart disease in Europe and the United States have expanded the indications for transcatheter aortic valve implantation (TAVI) to younger patients and those at lower surgical risk with severe symptomatic aortic stenosis. Consequently, the number of TAVI procedures will significantly increase worldwide. Patients with longer life expectancies will outlive their transcatheter heart valves (THVs) and require established treatment strategies for re-intervention. Current data have shown encouraging outcomes, including low mortality, with redo-TAVI; in contrast, surgical explantation of THVs is associated with high mortality. Redo-TAVI, therefore, is likely to be the treatment of choice for THV failure. The expected increase in the number of redo-TAVIs stands in contrast to the current lack of evidence on how this procedure should be planned and performed, including the risks and pitfalls operators need to consider. Preliminary reports stress the importance of preprocedural planning, understanding of THV skirt and leaflet characteristics, and implantation guidelines specific to different THVs. Currently, SAPIEN 3/Ultra is the only THV approved in Europe and the United States for redo-TAVI. Therefore, we gathered a panel of experts in TAVI procedures with the aim of providing operative guidance on redo-TAVI, using the SAPIEN 3/Ultra THV. This consensus article presents a step-by-step approach encompassing clinical, anatomical, and technical aspects in preprocedural planning, procedural techniques, and postprocedural care. In conclusion, the recommendations aim to improve the feasibility, safety, and long-term outcomes of redo-TAVI, including the durability of implanted THVs. Transcatheter aortic valve (TAV) implantation (TAVI) has become a widely accepted routine therapy for patients with symptomatic severe aortic valve stenosis. It is recommended by European (European Society of Cardiology/European Association for Cardio-Thoracic Surgery) and American (American Heart Association/American Association for Thoracic Surgery) guidelines in the presence of a heart team consensus.1Vahanian A Beyersdorf F Praz F Milojevic M Baldus S Bauersachs J Capodanno D Conradi L De Bonis M De Paulis R Delgado V Freemantle N Gilard M Haugaa KH Jeppsson A Jüni P Pierard L Prendergast BD Sádaba JR Tribouilloy C Wojakowski W ESC/EACTS Scientific Document Group2021 ESC/EACTS Guidelines for the management of valvular heart disease.Eur Heart J. 2022; 43: 561-632Crossref PubMed Scopus (1361) Google Scholar,2Otto CM Nishimura RA Bonow RO Carabello BA Erwin 3rd, JP Gentile F Jneid H Krieger EV Mack M McLeod C O'gara PT Rigolin VH Sundt 3rd, TM Thompson A Toly C. 2020 ACC/AHA guideline for the management of patients with valvular heart disease: executive summary: A report of the American College of Cardiology/American Heart Association joint committee on clinical practice guidelines.Circulation. 2021; 143: e35-e71PubMed Google Scholar Recent randomized controlled trials have shown the noninferiority of TAVI to surgical aortic valve replacement (SAVR) in patients with low risk,3Smith CR Leon MB Mack MJ Miller DC Moses JW Svensson LG Tuzcu EM Webb JG Fontana GP Makkar RR Williams M Dewey T Kapadia S Babaliaros V Thourani VH Corso P Pichard AD Bavaria JE Herrmann HC Akin JJ Anderson WN Wang D Pocock SJ PARTNER Trial InvestigatorsTranscatheter versus surgical aortic-valve replacement in high-risk patients.N Engl J Med. 2011; 364: 2187-2198Crossref PubMed Scopus (4995) Google Scholar,4Popma JJ Deeb GM Yakubov SJ Mumtaz M Gada H O'Hair D Bajwa T Heiser JC Merhi W Kleiman NS Askew J Sorajja P Rovin J Chetcuti SJ Adams DH Teirstein PS Zorn 3rd, GL Forrest JK Tchétché D Resar J Walton A Piazza N Ramlawi B Robinson N Petrossian G Gleason TG Oh JK Boulware MJ Qiao H Mugglin AS Reardon MJ Evolut Low Risk Trial InvestigatorsTranscatheter aortic-valve replacement with a self-expanding valve in low-risk patients.N Engl J Med. 2019; 380: 1706-1715Crossref PubMed Scopus (2130) Google Scholar accelerating the expansion of TAVI into younger patients with longer life expectancies. All approved transcatheter heart valves (THVs) are based on biologic tissue prone to structural valve degeneration over time. Therefore, younger patients treated by TAVI will present increasingly frequently with bioprosthetic valve failure and the need for re-intervention, including redo-TAVI. However, although TAVI has already proved to be a safe and effective treatment for patients with degenerated surgical bioprostheses (TAV-in-SAV) surgical aortic valve,5Tuzcu EM Kapadia SR Vemulapalli S Carroll JD Holmes DR Jr Mack MJ Thourani VH Grover FL Brennan JM Suri RM Dai D Svensson LG Transcatheter aortic valve replacement of failed surgically implanted bioprostheses: the STS/ACC registry.J Am Coll Cardiol. 2018; 72: 370-382Crossref PubMed Scopus (123) Google Scholar data on the use of TAVI in degenerated TAVI prostheses (redo-TAVI) are still scarce. Early retrospective registries in small numbers of patients have shown no signal for increased procedural risk for redo-TAV compared with TAV-in-SAV.6Landes U Sathananthan J Witberg G De Backer O Sondergaard L Abdel-Wahab M Holzhey D Kim WK Hamm C Buzzatti N Montorfano M Ludwig S Conradi L Seiffert M Guerrero M El Sabbagh A Rodés-Cabau J Guimaraes L Codner P Okuno T Pilgrim T Fiorina C Colombo A Mangieri A Eltchaninoff H Nombela-Franco L Van Wiechen MPH Van Mieghem NM Tchétché D Schoels WH Kullmer M Tamburino C Sinning JM Al-Kassou B Perlman GY Danenberg H Ielasi A Fraccaro C Tarantini G De Marco F Redwood SR Lisko JC Babaliaros VC Laine M Nerla R Castriota F Finkelstein A Loewenstein I Eitan A Jaffe R Ruile P Neumann FJ Piazza N Alosaimi H Sievert H Sievert K Russo M Andreas M Bunc M Latib A Godfrey R Hildick-Smith D Chuang MA Blanke P Leipsic J Wood DA Nazif TM Kodali S Barbanti M Kornowski R Leon MB Webb JG Transcatheter replacement of transcatheter versus surgically implanted aortic valve bioprostheses.J Am Coll Cardiol. 2021; 77: 1-14Crossref PubMed Scopus (43) Google Scholar However, little is known about the best approach to plan and perform redo-TAVI. Procedural planning of redo-TAVI requires careful assessment of specific valve characteristics because all TAVI prostheses have different technical and structural specifications, including mode of deployment (balloon-expandable valve [BEV] vs self-expanding valve [SEV] vs mechanically expanded valve [MEV]), valve function (intra-annular vs supra-annular), and valve design (skirt-height, stent frame design, and height, and so on). Individual patient anatomy and the position and expansion of the index THV in relation to that anatomy will also critically affect the redo-TAVI procedure. These differences mandate a tailored approach to each individual redo-TAVI procedure. The key considerations in procedural planning will be the reduction of periprocedural risk, optimization of hemodynamic performance, and maintenance of coronary access. This article aims to provide an expert consensus on how to plan and perform redo-TAVI in different types of failing TAVI prostheses using the balloon-expandable SAPIEN family prosthesis, which is the only device with regulatory approval for this indication in both Europe and the United States. BEVs, SEVs, and MEVs are very different targets for re-intervention. A comprehensive understanding of stent design, valve design, and implant specifics is needed for proper planning of redo-TAVI. Figure 1 gives an overview of the various types of approved TAVI valves. Some are still in routine use; others are no longer available. Various technical design specifics of the different THV types must be considered when redo-TAVI is planned and performed, including the stent frame height, stent cell form and size, stent expansion, commissural stent post height, valve position and height, skirt length, and the degree and form of stent expansion. In addition, the anatomical position of the index THV is highly important for a successful procedure, including implant height, commissural alignment to coronary ostia, distance of coronary ostia in relation to stent frame and leaflets, size of native annulus and left ventricular outflow (LVOT) tract, degree and distribution of native valve calcification, size and height of sinotubular junction (STJ), and valve position in relation to annulus plane (straight or canted). Knowledge of specific index THV dimensions given by the manufacturers allows an accurate choice of redo-TAVI valve type and size. It is essential, however, to bear in mind that the actual dimensions of the index THV in specific patient anatomies may differ from those described in technical sizing charts. Detailed computed tomography (CT) scan analysis, therefore, is critical. Figure 2 gives a detailed overview of design specifications and dimensions for all available THV systems. The reasons for THV structural valve deterioration requiring redo-TAVI include malposition, underexpansion, paravalvular leakage (PVL), valve thrombosis, or valve migration. This manuscript focuses solely on redo-TAVI for structural valve deterioration according to the Valve Academic Research Consortium-3 definitions: intrinsic permanent changes to the prosthetic valve and valve stent because of wear and tear, leaflet disruption, flail leaflet, leaflet fibrosis and/or calcification, and stent strut fracture or deformation.7Généreux P Piazza N Alu MC Nazif T Hahn RT Pibarot P Bax JJ Leipsic JA Blanke P Blackstone EH Finn MT Kapadia S Linke A Mack MJ Makkar R Mehran R Popma JJ Reardon M Rodes-Cabau J Van Mieghem NM Webb JG Cohen DJ Leon MB VARC-3 Writing CommitteeValve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research.J Am Coll Cardiol. 2021; 77: 2717-2746Crossref PubMed Scopus (259) Google Scholar Structural valve deterioration is likely to cause hemodynamic changes over time and can eventually lead to bioprosthetic valve failure. When leading to THV stenosis, severe hemodynamic valve deterioration is an increase in the mean transvalvular gradient ≥20 mm Hg resulting in mean gradient ≥30 mm Hg, with a concomitant decrease in effective orifice area ≥0.6 cm² or ≥50%, and/or decrease in Döppler velocity index ≥0.2 or ≥40%, compared with echocardiographic assessment performed 1 to 3 months after the procedure. If THV regurgitation is the leading mode of failure, a new occurrence or increase of ≥2 grades of intraprosthetic aortic regurgitation (AR) resulting in severe AR is an indication for further treatment, including the option of redo-TAVI.7Généreux P Piazza N Alu MC Nazif T Hahn RT Pibarot P Bax JJ Leipsic JA Blanke P Blackstone EH Finn MT Kapadia S Linke A Mack MJ Makkar R Mehran R Popma JJ Reardon M Rodes-Cabau J Van Mieghem NM Webb JG Cohen DJ Leon MB VARC-3 Writing CommitteeValve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research.J Am Coll Cardiol. 2021; 77: 2717-2746Crossref PubMed Scopus (259) Google Scholar An expert heart team can decide on the patient's suitability for redo-TAVI after a detailed assessment including echocardiography and electrocardiogram (ECG)-gated CT of the index valve, in addition to evaluation of the pre–index TAVI CT whenever possible. In the next sections, the authors will provide structured guidance on how to plan and perform redo-TAVI using the Edwards SAPIEN family BEVs in a variety of THV models and patient anatomies. Transcatheter treatment of a failed THV requires unique technical considerations that affect both procedural risk and long-term outcomes, such as valve hemodynamics, durability, and coronary access. An understanding of specific novel terminologies is needed when planning and performing redo-TAVI procedures (Figure 3). After redo-TAVI, the leaflets of the failed THV—also called index THV—will be pushed open by the new, second THV, creating a "neoskirt" covered stent. The neoskirt height has important implications for the periprocedural risk of coronary obstruction and future coronary access. The height of the neoskirt varies across different THV designs.8Akodad M Sellers S Gulsin GS Tzimas G Landes U Chatfield AG Chuang A Meier D Leipsic J Blanke P Ye J Cheung A Wood DA Khan JM Webb JG Sathananthan J. Leaflet and neoskirt height in transcatheter heart valves: implications for repeat procedures and coronary access.JACC Cardiovasc Interv. 2021; 14: 2298-2300Crossref PubMed Scopus (9) Google Scholar The effective "functional" neoskirt height will vary according to the implantation depth of the index THV. If the index THV is deployed high relative to the annular plane of the aortic valve, this will result in a higher functional neoskirt than that of a low implant. If a short-frame THV is deployed in a failed tall-frame THV with supra-annular leaflets, the entire leaflets of the index THV may not be fully entrapped between the 2 THVs, especially if the second short-frame THV is implanted low. This will result in leaflet overhang that, depending on the extent, may affect valve performance, durability, and coronary access. The degree of leaflet overhang can be mitigated with a higher implant position of the second short-frame THV,9Sathananthan J Fraser R Landes U Rich C Sellers SL Leipsic J Blanke P Lutter G Frank D Puehler T Wood DA Søndergaard L Webb JG. Repeat transcatheter aortic valve implantation and implications for transcatheter heart valve performance: insights from bench testing.EuroIntervention. 2021; 17: 856-864Crossref PubMed Scopus (13) Google Scholar,10Akodad M Sellers S Landes U Meier D Tang GHL Gada H Rogers T Caskey M Rutkin B Puri R Rovin J Leipsic J Sondergaard L Grubb KJ Gleason P Garde K Tadros H Teodoru S Wood DA Webb JG Sathananthan J. Balloon-expandable valve for treatment of Evolut valve failure: implications on neoskirt height and leaflet overhang.JACC Cardiovasc Interv. 2022; 15: 368-377Crossref PubMed Scopus (17) Google Scholar as long as coronary access is not threatened. Use of a BEV for redo-TAVI can result in additional expansion of the failed index THV, which, in turn, may reduce the space in the sinuses of valsalva, increasing the risk of sinus sequestration and/or coronary obstruction. The degree of expansion of the index THV must be considered when performing preprocedural risk prediction for coronary obstruction. In most cases of redo-TAVI, the leaflets of the index THV will be maximally deflected outward to oppose the stent frame. The degree of leaflet deflection, however, may vary across THV types. For example, in a case of SAPIEN 3/Ultra implantation in a failed Acurate Neo, the leaflets are not maximally deflected, and there will be a space between the neoskirt and the frame of the index THV. A THV design in which the leaflets are not maximally deflected to the edge of the THV stent frame can mitigate the risk of coronary obstruction and difficult coronary access. If available, analysis of the pre–index-TAVI CT is recommended, to evaluate the native aortic root (including valve morphology, calcium distribution, and annular and LVOT dimensions), to determine whether the first THV was appropriately sized, and to identify unfavorable characteristics, such as severe annular/LVOT calcification, eccentricity, and bicuspid anatomy,11Tarantini G Fabris T. Transcatheter aortic valve replacement for bicuspid aortic valve stenosis: A practical operative overview.Circ Cardiovasc Interv. 2021; 14e009827Crossref PubMed Scopus (4) Google Scholar that may explain the mechanism of THV failure. Therefore, analysis of the pre–index-TAVI CT may contribute to better procedural planning for redo-TAVI, including predilatation and valve sizing. When planning redo-TAVI, detailed analysis of a preprocedural cardiac CT is mandatory to evaluate aortic root anatomy and to understand the position of the index THV in relation to its surrounding structures, and hence to assess and estimate the risk of coronary obstruction, sinus sequestration, and difficult coronary access. Although the analysis of a post–index-TAVI CT in preparation for redo-TAVI may seem complex, it can be simplified using a systematic step-by-step approach (Figure 4). As a first step, it is important to confirm that the implanted index THV type corresponds with the THV type specified in the procedure note. This requires knowledge of the exact design characteristics of the different THVs that have been and are commercially available. Valve size should also be confirmed, and that only 1 THV was implanted at the index procedure. Based on transthoracic and/or transesophageal echocardiography, the failure mode of the index THV should be known. In cases of a stenotic index THV, one should screen for and discriminate between hypo-attenuating leaflet thickening, pannus, and/or leaflet calcification. In cases of dominant regurgitation, it is crucial to distinguish valvular leakage from PVL. On the basis of the pre–redo-TAVI CT alone, it might be difficult to determine the exact position of the native aortic valve annular plane and hence, the exact implantation depth of the index THV. However, because the index THV stent frame will be used as the main "reference" for implantation of the second THV, all relevant measurements (THV expansion, valve-to-aorta [VTA] distances, coronary ostia height, so on) should also be made in relation to the inflow, node levels, waist, commissural posts, and/or outflow of the index THV. To adopt a systematic approach, we recommend defining the inflow of the index THV as the new "zero" plane and measuring index THV expansion and VTA distances for every stent frame node level, up to the outflow for BEV and MEV, and up to the outflow at the commissural posts for SEV (Figure 4). It is important to understand the percentage of oversizing/undersizing of the index THV, and to measure minimum internal diameter, maximum internal diameter, eccentricity, area-derived internal diameter, and perimeter-derived internal diameter. Furthermore, these measurements should be made at every stent frame node level of the index THV (Figure 4). Knowledge of these measurements will affect the anticipated possible further expansion of the index THV, depending on the choice of the second THV type and size. To fully understand the neosinus, valve-to-coronary, and valve-to-STJ distance, a systematic approach of measuring the VTA distance at every single stent frame node level is recommended. From these measurements, the valve-to-coronary and valve-to-STJ distances should be specifically noted for both the left and right coronary sinuses (Figure 4). It is important, however, to recognize that measured VTA distances may become shorter after the second THV implantation owing to index THV expansion (Figure 4). On the contrary, VTA distances may be greater than expected if the leaflets of the failing THV are not maximally deflected, such as with Acurate Neo. In planning redo-TAVI, the main focus is on the degree of THV commissure misalignment and on coronary ostial eccentricity in relation to the index THV cusps. Specifically, leaflet modification of the index THV, for example, by a bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction procedure, can only be effectively performed if the index THV commissural post is not facing the coronary ostium. Because 1 of the main concerns during a redo-TAVI procedure is the risk of coronary obstruction and difficult coronary access, detailed preprocedural "mapping" of the position of the coronary ostia in relation to the index THV and its commissures is essential (Figures 5 and 6).Figure 6Risk assessment of coronary obstruction in redo-TAVI.View Large Image Figure ViewerDownload Hi-res image Download (PPT) On the basis of the preprocedural cardiac CT analysis, one can also determine the fluoroscopic view (RAO/LAO, CAUD/CRAN) on the S-curve of the index THV in which the left and right coronary artery ostia will be lateralized. Knowing these fluoroscopic views can be helpful during redo-TAVI procedures and can also be used to facilitate selective catheterization of the coronary arteries (Figure 4). Finally, on the basis of the planned implantation (low, intermediate, or high) of the second THV, one can determine the anticipated neoskirt height, and estimate the neoskirt-to-coronary distance and neoskirt-to-STJ distance. Again, these neoskirt-to-aorta distances may become shorter than the measured VTA distances, depending on the second THV type and size, and index THV expansion (Figure 4). For the sizing of the second THV, multiple parameters must be considered, and a case-based approach is necessary. Both oversizing and undersizing confer risks that should be avoided. Significant oversizing is rarely needed in redo-TAVI, unless the failure mechanism of the index prosthesis is significant PVL, whereas undersizing of the second prosthesis may risk valve migration or embolization if the frame-to-frame interaction of the 2 THVs does not provide sufficient force for secure anchoring. Depending on the index THV (Figures 1 and 2), the sizing considerations, below, for redo-TAVI with SAPIEN 3/Ultra are recommended (Figure 7). Figure 8 depicts a suggested preprocedural redo-TAVI check list.Figure 8Checklist for redo-TAVI preprocedural planning. LCA = left circumflex artery; PPM = patient-prosthesis mismatch; PRVL = paravalvular leakage; RCA = right circumflex artery; SOV = sinus of valsalva.View Large Image Figure ViewerDownload Hi-res image Download (PPT) If the index BEV is fully expanded, there is no need for oversizing, and the same sizing should be considered for the second THV as for the index THV. If there is significant underexpansion without PVL (such as in severely calcific and/or bicuspid anatomies), downsizing may be necessary, particularly if the native anatomy carries high risk features for aortic injury.12Tarantini G Fabris T Cardaioli F Nai Fovino L. Coronary access after transcatheter aortic valve replacement in patients with bicuspid aortic valve: lights and shades.JACC Cardiovasc Interv. 2019; 12: 1190-1191Crossref PubMed Scopus (25) Google Scholar Nevertheless, these cases might present higher risk of final patient-prosthesis mismatch after redo-TAVI. In the case of significant underexpansion with PVL, upsizing of the second THV should be considered, with or without predilatation with a noncompliant balloon. In failing SEVs, it is important to determine the actual internal dimensions of the index THV from the pre–redo-TAVI CT. Understanding the SEV stent design and dimensions of inflow, waist, and outflow is also essential. Specifically, the inflow or waist portion of the SEV should be used as a reference because this should ensure that the risk of migration of the second THV is minimized. Furthermore, implantation of a BEV prosthesis may expand the dimensions of the SEV up to 2.5 mm at the waist.10Akodad M Sellers S Landes U Meier D Tang GHL Gada H Rogers T Caskey M Rutkin B Puri R Rovin J Leipsic J Sondergaard L Grubb KJ Gleason P Garde K Tadros H Teodoru S Wood DA Webb JG Sathananthan J. Balloon-expandable valve for treatment of Evolut valve failure: implications on neoskirt height and leaflet overhang.JACC Cardiovasc Interv. 2022; 15: 368-377Crossref PubMed Scopus (17) Google Scholar To estimate this effect, it is important to know the anatomy before implantation of the index THV (native annular dimensions, annular and LVOT calcification, STJ dimensions), in addition to implantation depth.13Nai Fovino L Cipriani A Fabris T Massussi M Scotti A Lorenzoni G Guerra MC Cardaioli F Rodinò G Matsuda Y Masiero G Leoni L Zorzi A Fraccaro C Tarantini G Anatomical predictors of pacemaker dependency after transcatheter aortic valve replacement.Circ Arrhythm Electrophysiol. 2021; 14e009028Crossref PubMed Scopus (24) Google Scholar In particular, awareness of any over- or undersizing of the index THV is important when selecting the size of the BEV. As a rough guide, if the size of the first THV is correct and no significant underexpansion is present, the following recommendation can be made: SAPIEN 3 20 mm in a 23 mm CoreValve/Evolut, SAPIEN 3 23 mm in a 26 mm CoreValve/Evolut, SAPIEN 3 26 mm in a 29 mm CoreValve/Evolut, and SAPIEN 3 29 mm in a 34 mm CoreValve/Evolut; for Acurate Neo/Neo2: SAPIEN 3 23 mm in Acurate Neo S, SAPIEN 3 23/26 mm in Acurate Neo M, SAPIEN 3 26/29 mm in Acurate Neo L. Importantly, SAPIEN 3/Ultra THV upsizing might be considered when aiming for a low implantation (especially in case of index SE THV regurgitation as the prevalent failure mechanism), depending on native annular valve anatomy (i.e., the baseline native anatomy needs to be large enough to accommodate the larger THV). Implantation of a BEV of the same size is recommended, considering the real internal dimensions of the MEV. Extreme caution should be taken if postdilatation is necessary to achieve optimal hemodynamics because this maneuver may break or disrupt the MEV locking mechanism. Undersizing of BEV might be considered if the index MEV is underexpanded without PVL, especially in hostile anatomy. As with the selection of size of the second THV, correct positioning depends on several different factors. As a general principle, positioning of the second THV should be aimed at optimizing post–redo-TAVI hemodynamics, while minimizing the risk of coronary occlusion and/or sinus sequestration. The risk of coronary occlusion can be reduced by a low implantation of the second THV, accepting variable degrees of leaflet overhang. Leaflet overhang may not necessarily impair final redo-TAVI hemodynamics (i.e., may not result in residual gradient), particularly if the failure mechanism of the first THV was regurgitation. Depending on the index prosthesis (Figure 7), the following considerations for SAPIEN 3/Ultra implantation during redo-TAVI are advisable. The short stent frame of a BEV or MEV and the intra-annular leaflet design result in a lower risk of compromised coronary access after redo-TAVI because the coronary ostia will be above the stent frame in approximately 2/3 of cases.14Tarantini G Fabris T Nai Fovino L TAVR-in-TAVR and coronary access: importance of preprocedural planning.EuroIntervention. 2020; 16: e129-e132Crossref PubMed Scopus (35) Google Scholar, 15Tarantini G Nai Fovino L Le Prince P Darremont O Urena M Bartorelli AL Vincent F Hovorka T Alcalá Navarro Y Dumonteil N Ohlmann P Wendler O Coronary access and percutaneous coronary intervention UP to 3 years after transcatheter aortic valve implantation with a balloon-expandable valve.Circ Cardiovasc Interv. 2020; 13e008972Crossref Scopus (27) Google Scholar, 16Ochiai T Chakravarty T Yoon SH Kaewkes D Flint N Patel V Mahani S Tiwana R Sekhon N Nakamura M Cheng W Makkar R. Coronary access after TAVR.JACC Cardiovasc Interv. 2020; 13: 693-705Crossref PubMed Scopus (96) Google Scholar, 17Forrestal BJ Case BC Yerasi C Shea C Torguson R Zhang C Ben-Dor I Deksissa T Ali S Satler LF Shults C Weissman G Wang JC Khan JM Waksman R Rogers T. Risk of coronary obstruction and feasibility of coronary access after repeat transcatheter aortic valve replacement with the self-expanding Evolut valve: a computed tomography simulation study.Circ Cardiovasc Interv. 2020; 13e009496Crossref PubMed Scopus (28) Google Scholar, 18Nai Fovino L Scotti A Massussi M Fabris T Cardaioli F Rodinò G Matsuda Y Frigo F Fraccaro C Tarantini G Incidence and feasibility of coronary access after transcatheter aortic valve replacement.Catheter Cardiovasc Interv. 2020; 96: E535-E541Crossref PubMed Scopus (41) Google Scholar, 19Tarantini G Nai Fovino L Coronary access and TAVR-in-TAVR: don't put off until tomorrow what you can do today.JACC Cardiovasc Interv. 2020; 13: 2539-2541Crossref PubMed Scopus (12) Google Scholar If this is not the case, the VTA should b