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:OBJECTIVE:Valve-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. METHODS:A 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. RESULTS:Velocity 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. CONCLUSIONS:Decreased 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: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.
Project description:An 80-year-old male underwent a transcatheter aortic valve implantation (TAVI) for severe senile aortic stenosis. Six weeks after the surgery, he was readmitted to our institution because of a high-grade fever. Transesophageal echocardiography revealed thickening of all three leaflets of the aortic prosthesis and mobile mass on the leaflet, and Streptococcus sanguis was identified from his blood culture. Therefore, he was diagnosed with prosthetic valve endocarditis (PVE) and received intensive intravenous antibiotic therapy. Because he did not respond to the pharmacological therapy, surgical aortic valve replacement (AVR) was indicated although it was considered a relatively high-risk procedure. Herein, we report on the successful surgical AVR in this patient using a pericardial valve after removal of the infected prosthetic valve, and discuss some issues related to this rare complication after TAVI. <Learning objective: Transcatheter aortic valve implantation (TAVI) is a highly effective procedure for patients with symptomatic severe aortic stenosis who are at high risk or deemed inoperable. Because it only requires limited surgical invasiveness, the risk of prosthetic valve endocarditis (PVE) after TAVI is thought to be low. However, PVE can occur even early after TAVI. We present our recent such case and discuss some issues related to this rare complication.>.
Project description:This original clinical research study id focused on description of baseline anatomy and outcomes after transcatheter aortic valve implantation (TAVI) in patients presenting with severe aortic stenosis (AS) and bicuspid aortic valve (BAV). We compared this BAV population with a population of patients with AS and tricuspid aortic valves after a propensity score matching developed by a multivariate logistic regression according to a non-parsimonious approach. Baseline anatomical characteristics were obtained by transthoracic echocardiography (TTE) and multi-sliced computed tomography (MSCT) and compared by chi-square and t-student tests. Outcomes were evaluated by correct fisher test at in hospital and 30 days follow-up. We found that BAV patients presents more complicated baseline anatomy as compared to patients with tricuspid valves. These anatomical features lead to higher procedural complications as the need for a second device implantation. However this does not translate into increase in mortality rate at 30 days follow-up but rather correlate to a lower device success rate.
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:AimsTo study sex-specific differences in the amount and distribution of aortic valve calcification (AVC) and to correlate the AVC load with paravalvular leakage (PVL) post-transcatheter aortic valve intervention (TAVI).Methods and resultsThis registry included 1801 patients undergoing TAVI with a Sapien3 or Evolut valve in two tertiary care institutions. Exclusion criteria encompassed prior aortic valve replacement, suboptimal multidetector computed tomography (MDCT) quality, and suboptimal transthoracic echocardiography images. Calcium content and distribution were derived from MDCT. In this study, the median age was 81.7 (25th-75th percentile 77.5-85.3) and 54% male. Men, compared to women, were significantly younger [81.2 (25th-75th percentile 76.5-84.5) vs. 82.4 (78.2-85.9), P ≤ 0.01] and had a larger annulus area [512 mm2 (25th-75th percentile 463-570) vs. 405 mm2 (365-454), P < 0.01] and higher Agatston score [2567 (25th-75th percentile 1657-3913) vs. 1615 (25th-75th percentile 905-2484), P < 0.01]. In total, 1104 patients (61%) had none-trace PVL, 648 (36%) mild PVL, and 49 (3%) moderate PVL post-TAVI. There was no difference in the occurrence of moderate PVL between men and women (3% vs. 3%, P = 0.63). Cut-off values for the Agatston score as predictor for moderate PVL based on the receiver-operating characteristic curve were 4070 (sensitivity 0.73, specificity 0.79) for men and 2341 (sensitivity 0.74, specificity 0.73) for women.ConclusionAVC is a strong predictor for moderate PVL post-TAVI. Although the AVC load in men is higher compared to women, there is no difference in the incidence of moderate PVL. Sex-specific Agatston score cut-offs to predict moderate PVL were almost double as high in men vs. women.