Project description:Transcatheter aortic valve implantation (TAVI) is the standard of care for symptomatic severe aortic stenosis. Antithrombotic therapy is required after TAVI to prevent thrombotic complications but it increases the risk of bleeding events. Current clinical guidelines are mostly driven by expert opinion and therefore yield low-grade recommendations. The optimal antithrombotic regimen following TAVI has yet to be determined and several randomised controlled trials assessing this issue are ongoing. The purpose of this article is to critically explore the impact of antithrombotic drugs, especially anticoagulants, on long-term clinical outcomes following successful TAVI.
Project description:BackgroundEven after decades of intensive research, an ideal heart valve prosthesis remains elusive. Shortcomings of conventional devices include reduced durability of bioprostheses and the thrombogenicity of mechanical substitutes, necessitating anticoagulation and resulting in imperfect hemodynamics. Here we present in vivo results of a novel mechanical heart valve prosthesis aiming for freedom from anticoagulation.MethodsFour female sheep had their aortic valves replaced using the novel mechanical heart valve (size 21 mm), with no postoperative anticoagulation treatment. This trileaflet heart valve was designed with the pivots in the systolic central flow. Hemodynamics, biochemistry, hematology, and macroscopy and microscopy were studied at 90 days in 2 sheep and at 1 year in the other 2 sheep.ResultsMean (<6 mm Hg) and peak (<10 mm Hg) aortic transvalvular gradients remained low during the study period. Aortic regurgitation was trivial, and central traces were only rarely observed. The rate of thrombotic events was very low, with none macroscopically and microscopically visible thrombotic material on the device. Biochemistry and hemotology were unchanged without hemolysis. In 3 sheep, the fibrous pannus and mitral leaflet were partially folded over the edge of the annular body. Apart from organic/inorganic deposits on the leaflets after 1 year, the ultrastructurally evaluated leaflets were similar to those of nonimplanted controls.ConclusionsThe preliminary in vivo results of this novel anticoagulation-free aortic mechanical heart valve are promising with excellent hemodynamics and a very low risk of thrombotic events.
Project description:We report a case of an 84-year-old man with a history of surgical aortic-valve replacement for chronic aortic regurgitation (AR) who later developed severe prosthetic valve AR. Subsequent treatment with a Corevalve® was unsuccessful with severe AR seen at 3 years after the valve-in-valve procedure. The patient was then successfully treated with a second catheter-based Corevalve® implantation.
Project description:ObjectiveValve-in-valve transcatheter aortic valve implantation (ViV-TAVI) has emerged as a useful alternative intervention to redo-surgical aortic valve replacement (Redo-SVAR) for the treatment of degenerated bioprosthesis valve. However, there is no robust evidence about the long-term outcome of both treatments. The aim of this meta-analysis was to analyze the long-term outcomes of Redo-SVAR versus ViV-TAVI by reconstructing the time-to-event data.MethodsThe search strategy consisted of a comprehensive review of relevant studies published between 1 January 2000 and 30 September 2022 in three electronic databases, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE. Relevant studies were retrieved for the analysis. The primary endpoint was the long-term mortality for all death. The comparisons were made by the Cox regression model and by landmark analysis and a fully parametric model. A random-effect method was applied to perform the meta-analysis.ResultsTwelve studies fulfilled the eligibility criteria and were included in the final analysis. A total of 3547 patients were included. Redo-SAVR group included 1783 patients, and ViV-TAVI included 1764 subjects. Redo-SAVR showed a higher incidence of all-cause mortality within 30-days [Hazard ratio (HR) 2.12; 95% CI = 1.49-3.03; p < 0.0001)], whereas no difference was observed between 30 days and 1 year (HR = 1.03; 95% CI = 0.78-1.33; p = 0.92). From one year, Redo-SAVR showed a longer benefit (HR = 0.52; 95% CI = 0.40-0.67; p < 0.0001). These results were confirmed for cardiovascular death (HR = 2.04; 95% CI = 1.29-3.22; p = 0.001 within one month from intervention; HR = 0.35; 95% CI = 0.18-0.71; p = 0.003 at 4-years follow-up).ConclusionsAlthough the long-term outcomes seem similar between Redo-SAVR and ViV-TAVI at a five-year follow-up, ViV-TAVI shows significative lower mortality within 30 days. This advantage disappeared between 30 days and 1 year and reversed in favor of redo-SAVR 1 year after the intervention.
Project description:ObjectiveValve-in-valve procedures using transcatheter aortic valves are increasingly performed to treat degenerated bioprosthetic surgical aortic valves because they are less invasive than redo aortic valve replacement. The objective of this study is to quantify the changes in aortic sinus blood flow dynamics before and after a valve-in-valve procedure to gain insight into mechanisms for clinical and subclinical thrombosis of leaflets.MethodsA detailed description of the sinus hemodynamics for valve-in-valve implantation was performed in vitro. A Medtronic Hancock II (Medtronic Inc, Minneapolis, Minn) porcine bioprosthesis was modeled as a surgical aortic valve, and Medtronic CoreValve and Edwards Sapien (Edwards Lifesciences, Irvine, Calif) valves were used as the transcatheter aortic valves. High-resolution particle image velocimetry was used to compare the flow patterns from these 2 valves within both the left coronary and noncoronary sinuses in vitro.ResultsVelocity and vorticity within the surgical valve sinuses reached peak values of 0.7 m/s and 1000 s-1, with a 70% decrease in peak fluid shear stress near the aortic side of the leaflet in the noncoronary sinus. With the introduction of transcatheter aortic valves, peak velocity and vorticity were reduced to approximately 0.4 m/s and 550 s-1 and 0.58 m/s and 653 s-1 without coronary flow and 0.60 m/s and 631 s-1 and 0.81 m/s and 669 s-1 with coronary flow for the CoreValve and Sapien valve-in-valve implantations, respectively. Peak shear stress was approximately 38% higher along the aortic side of the coronary versus noncoronary transcatheter aortic valve leaflet.ConclusionsDecreased flow and shear stress in valve-in-valve procedures indicate a higher risk of leaflet thrombosis secondary to flow stasis, perhaps more so in the noncoronary sinus.
Project description:Although the results of the early TAVI experience are promising, longer-term follow-up is necessary before the procedure can be extended to lowerrisk patients. Many issues are not yet resolved, including the long-term effects of paravalvular leaks (which occur in most TAVI patients), the true stroke rate in TAVI patients (which is probably in the range of 5% to 6%), and the need for permanent pacemaker implantation (which ranges from 5% to 40% in TAVI patients, depending upon the device used). As the procedure is extended into the lower-risk population, these issues will assume greater import than they have in the population currently in treatment—very elderly, high-risk patients with limited life expectancy. As in the coronary-revascularization paradigm of percutaneous coronary intervention versus coronary artery bypass grafting, there will be increasing adoption of the transcatheter approach. Just as the rumors of the demise of surgical bypass were premature, conventional AVR will continue to be the predominant technique for the treatment of aortic stenosis during at least the next decade. Although the percentage of patients treated by a transcatheter approach will continue to increase, regulatory and reimbursement factors are likely to be the primary determinants of the rate of adoption.
Project description:Transcatheter aortic valve implantation has emerged as a valuable option to treat patients with symptomatic severe aortic stenosis, who are not being considered for surgery because of significant comorbidities. Concerns exist over treating patients who have previously undergone mitral valve surgery for possible interference between the percutaneous aortic valve and the mitral prosthesis or ring.At our centre, from May 2008 to December 2012, 172 patients (76 male) with severe symptomatic aortic stenosis were eligible for transcatheter aortic valve implant. Nine patients, affected by severe aortic stenosis, had previously undergone mitral valve surgery (4 mono-leaflet, 3 bileaflet, 1 bioprosthesis, 1 mitral ring); they were considered high-risk surgical candidates following joint evaluation by cardiac surgeons and cardiologist and had undergone TAVI.Seven patients underwent standard femoral retrograde CoreValve(®) (Medtronic Inc., Minneapolis, USA) implantation, two patients underwent a direct aortic implantation through a mini-thoracotomy. All patients experienced immediate improvement of their haemodynamic status. No deformation of the nitinol tubing of the CoreValve, nor distortion or malfunction of the mechanical valve or mitral ring, occurred as assessed by echographical and fluoroscopic evaluation. No major postoperative complications occurred. In all patients , echocardiography indicated normal valve function during follow-up.Our experience confirms the feasibility of CoreValve implantation in patients with mechanical mitral valves or mitral annuloplasty ring.
Project description:BackgroundValve-in-valve transcatheter aortic valve implantation (TAVI) has emerged as a competent alternative for the treatment of degenerated bioprosthetic valves after surgical aortic valve replacement, or during TAVI procedure as a bailout option. Herein, we report a rare case of a self-expandable Medtronic Evolut R valve into a failing Medtronic CoreValve, with the use of modern pre-TAVI imaging screening, suggesting the proper procedural design steps for so complicated implantations.Case summaryA frail 78-year-old woman with a degenerated Medtronic Core Valve 26 mm bioprosthesis, implanted in 2011 due to severe aortic stenosis, was referred to our hospital due to worsening dyspnoea New York Heart Association III. The screening echocardiography documented severe aortic stenosis, while the classical risk scores were in favour of repeated TAVI (EuroSCORE II 5.67%). Computed tomography measurements and three-dimensional (3D) printing model were of great help for the proper valve selection (Medtronic Evolut R 26 mm), while the use of cerebral protection device (Claret Sentinel) was considered as a necessary part of the procedure. The simultaneous use of fluoroscopy and transoesophageal echocardiogram led to optimal haemodynamic result, confirmed by the discharge echocardiogram, with a significant clinical improvement during the first month follow-up.DiscussionThe main periprocedural concerns remain valve malpositioning, coronary artery obstruction, and high remaining transvalvular gradients. The multimodality pre-TAVI imaging screening may be helpful for precise procedural design. Despite the limited use of 3D models, it is necessary to adopt such tissue-mimicking phantoms to increase the possibility of optimal procedural result.