Transcatheter aortic valve implantation (TAVI): state of the art techniques and future perspectives.

Transcatheter aortic valve therapies are the newest established techniques for the treatment of high risk patients affected by severe symptomatic aortic valve stenosis. The transapical approach requires a left anterolateral mini-thoracotomy, whereas the transfemoral method requires an adequate peripheral vascular access and can be performed fully percutaneously. Alternatively, the trans-subclavian access has been recently proposed as a third promising approach. Depending on the technique, the fine stent-valve positioning can be performed with or without contrast injections. The transapical echo-guided stent-valve implantation without angiography (the Lausanne technique) relies entirely on transoesophageal echocardiogramme imaging for the fine stent-valve positioning and it has been proved that this technique prevents the onset of postoperative contrast-related acute kidney failure. Recent published reports have shown good hospital outcomes and short-term results after transcatheter aortic valve implantation, but there are no proven advantages in using the transfemoral or the transapical technique. In particular, the transapical series have a higher mean logistic Euroscore of 27-35%, a procedural success rate above 95% and a mean 30-day mortality between 7.5 and 17.5%, whereas the transfemoral results show a lower logistic Euroscore of 23-25.5%, a procedural success rate above 90% and a 30-day mortality of 7-10.8%. Nevertheless, further clinical trials and long-term results are mandatory to confirm this positive trend. Future perspectives in transcatheter aortic valve therapies would be the development of intravascular devices for the ablation of the diseased valve leaflets and the launch of new stent-valves with improved haemodynamic, different sizes and smaller delivery systems.

Use of a ventricular septal defect occluder for apical closure in transapical aortic valve replacement.

During transapical transcatheter aortic valve replacement (TA-TAVR), the apical closure remains a challenge for the surgeon, having the risk for ventricular tear and massive bleeding. Apical closure devices are already under clinical evaluation, but only a few can lead to a full percutaneous TA-TAVR. We describe the successful use of a 9-mm myocardial occluder (ventricular septal defect occluder) that was used to seal the apex after a standard TA-TAVR (using the Sapien XT 23-mm transcatheter valve and the Ascendra + delivery system). The placement of the nonmodified myocardial occluder was performed through the Ascendra + delivery system, with a very small amount of blood loss and an acceptable sealing of the apical tear. This approach is feasible and represents a further step toward true-percutaneous transapical heart valve procedures. Modified apical occluders are under evaluation in animal models.

Dinámica del anillo mitral en pacientes con insuficiencia mitral isquemica

OBJETIVOS: Describir y comparar los cambios dinámicos de la geometría del anillo mitral durante todo el ciclo cardiaco en pacientes con insuficiencia mitral isquémica y pacientes con válvula mitral normal. MATERIALES Y MÉTODOS: Los estudios ecocardiográficos analizados fueron 37, 23 con insuficiencia mitral isquémica y 14 con válvula mitral normal. La reconstrucción del anillo se realizó en la estación de trabajo Xcelera (Philips Medial Systems) mediante la herramienta de análisis mitral (MVQ), en 5 momentos del ciclo cardiaco: Comienzo de Sístole, Mitad de Sístole, Final de Sístole, Mitad de Diástole y Final de Diástole. RESULTADOS: El anillo del grupo control, fue más dinámico, con sus menores dimensiones al final de la diástole, presentando incremento progresivo durante la sístole. Los cambios en el perímetro y el área, fueron significativos entre el comienzo y mitad de la sístole (p:0.087 y p: 0.055). En el grupo con insuficiencia mitral isquémica, el anillo fue más estático. Todas las dimensiones en este grupo, fueron mayores en los cinco momentos del ciclo cardiaco. (p < 0.1). El anillo también fue más plano, con un índice morfológico anular menor al del grupo control (p:0.087). DISCUSIÓN Y CONCLUSIONES: En pacientes sin insuficiencia mitral, el anillo es una estructura dinámica. Durante la sístole, las menores dimensiones se produjeron al comienzo de este periodo y la conformación en silla de montar se mantuvo, protegiendo contra la insuficiencia mitral. El anillo del grupo con insuficiencia mitral fue más estático y plano, perdiendo los mecanismos protectores.

Role of nitric oxide in the remodelling of extracellular matrix in myxomatous mitral valve degeneration of dogs and pigs

Myxomatous mitral valve degeneration (MMVD) or endocardiosis is a heart valve disease that occurs in many mammalian species, especially in humans, dogs and pigs. Nitric oxide (NO) plays an important role in the MMVD development. NO can be indirectly evaluated by the nitric-oxide synthase (NOS) expression and by the histochemical reaction of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d). The aim of this study was to evaluate NOS activity, by NADPH-d reaction, in the anterior leaflet of dogs with regular mitral valves and in those with MMVD, as well as in young swine and old females, comparing the reaction level with the degree of endocardiosis disease and also the histological alterations. Twelve mitral valves of dogs and 22 of swine were used for the research. All the valves were macroscopically analyzed for the occurrence or not of endocardiosis. They were fixed in a 4% paraformaldehyde, exposed to NADPH-d reaction, routinely processed and microscopically evaluated for the detection of mucopolysaccharides (MPS) deposition, collagen degeneration, fibrosis and level of endocardiosis. In dogs, relation was observed between higher intensity of the NADPH-d reaction, higher endocardiosis degree, MPS deposition as well as the collagen degeneration. No alteration in color was observed in pigs ́ valves during NADPH-d reaction. In conclusion, NO works in canine mitral valve remodeling extracellular matrix and plays an important role in endocardiosis disease. In swine, the lack of reaction reinforces the absence of macroscopical endocardiosis lesions, suggesting restrict NO action or major differences in the structures of swine valves.

Energy Metabolism in Cardiac Remodeling and Heart Failure

Fatty acids are the main substrates used by mitochondria to provide myocardial energy under normal conditions. During heart remodeling, however, the fuel preference switches to glucose. In the earlier stages of cardiac remodeling, changes in energy metabolism are considered crucial to protect the heart from irreversible damage. Furthermore, low fatty acid oxidation and the stimulus for glycolytic pathway lead to lipotoxicity, acidosis, and low adenosine triphosphate production. While myocardial function is directly associated with energy metabolism, the metabolic pathways could be potential targets for therapy in heart failure. © 2013 by Lippincott Williams & Wilkins.

Mensuração do volume atrial esquerdo pelo método biplanar de Simpson em cães portadores da doença mixomatosa da válvula mitral

Pós-graduação em Medicina Veterinária - FCAV

Avaliação comparativa do uso da furosemida em bolus ou infusão contínua no tratamento de cães com doença degenerativa valvar

Pós-graduação em Medicina Veterinária - FCAV

Validation of the 2000 Bernstein-Parsonnet and EuroSCORE at the Heart Institute - USP

Objective: To validate the 2000 Bernstein Parsonnet (2000BP) and additive EuroSCORE (ES) to predict mortality in patients who underwent coronary bypass surgery and/or heart valve surgery at the Heart Institute, University of Sao Paulo (InCor/HC-FMUSP). Methods:A prospective observational design. We analyzed 3000 consecutive patients who underwent coronary bypass surgery and/or heart valve surgery, between May 2007 and July 2009 at the InCor/HC-FMUSP. Mortality was calculated with the 2000BP and ES models. The correlation between estimated mortality and observed mortality was validated by calibration and discrimination tests. Results: There were significant differences in the prevalence of risk factors between the study population, 2000BP and ES. Patients were stratified into five groups for 2000BP and three for the ES. In the validation of models, the ES showed good calibration (P = 0396), however, the 2000BP (P = 0.047) proved inadequate. In discrimination, the area under the ROC curve proved to be good for models, ES (0.79) and 2000BP (0.80). Conclusion: In the validation, 2000BP proved questionable and ES appropriate to predict mortality in patients who underwent coronary bypass surgery and/or heart valve surgery at the InCor/HC-FMUSP.

Transapical implantation of a novel self-expanding sutureless aortic valve prosthesis

To date, transapical aortic valve implantation has required a balloon-expandable stented valve prosthesis. More recently, a novel self-expanding sutureless stented bovine pericardial prosthesis has been developed which allows rapid aortic valve replacement via an open transaortic approach in humans. The aim of this animal study was to develop a reliable protocol to facilitate the transapical implantation of this self-expanding valve in a porcine model.

Transapical valve-in-valve implantation for regurgitant stented aortic bioprostheses

Transcatheter aortic valve implantation (TAVI) is rapidly evolving as an alternative treatment option for elderly patients with severe symptomatic aortic stenosis and excessive risk for surgical intervention. Transcatheter valve-in-valve implantation is an alternative approach to redo-surgery for patients with degeneration of a bioprosthetic valve. Herein are reported three cases of successful transcatheter aortic valve-in-valve implantation for severely regurgitant bioprosthetic valves with a clinical follow up of more than 12 months.

Transcatheter aortic valve implantation: the procedure

Transcatheter aortic valve implantation (TAVI) for the treatment of symptomatic severe aortic stenosis has emerged as an effective treatment for high risk patients. In 2002 TAVI was performed for the first time in a human by Alain Cribier, using an antegrade access approach via the femoral vein, crossing the intra-atrial septum after puncture and passing the native aortic valve in the direction of blood flow. This technically demanding approach was subsequently replaced by retrograde transfemoral arterial access. For patients with severe peripheral vascular disease or inadequately sized femoral arteries, the transapical route provides an alternative route with antegrade access to the aortic valve via puncture of the anterolateral wall of the left ventricle. The transsubclavian access approach using most frequently the left subclavian artery and direct transaortic access have been introduced more recently and attest to the versatility of TAVI in terms of access site. This article will focus on the different access site options available to operators, provide a step-by-step guide through the procedure, and a detailed description of the technological evolution of transcatheter heart valve systems.

Resuspension of the aortic valve in acute type A dissection: long-term results

BACKGROUND AND AIM OF THE STUDY: Preservation of the aortic valve during the repair of acute type A aortic dissection (AADA) is a viable option to prevent lifelong oral anticoagulation. The study aim was to assess aortic valve function following resuspension and supracoronary ascending aortic grafting. METHODS: Among a collective of 210 consecutive patients undergoing surgery for AADA, 140 (66.7%) with resuspension of the aortic valve and supracoronary ascending graft were analyzed. Of these patients, 83 (59.3%) had a complete follow up (mean 61.2 +/- 40.8 months), with 65 of the subgroup (78.3%) being followed by computed tomography scanning and echocardiography. RESULTS: Reoperation due to severe aortic valve regurgitation was required in seven patients (10.8%). The perioperative characteristics were similar in these patients; notably, no significant difference was evident with regards to the aortic annulus diameter and the severity of regurgitation at the time of surgery. The left ventricular mass index was significantly higher in patients requiring reoperation due to aortic valve regurgitation (219.3 +/- 146.6 versus 123.9 +/- 146.6 g/m2; p <0.05). None of the patients died as a result of reoperation. CONCLUSION: The long-term functional results following resuspension of the aortic valve in AADA were very good. A close echocardiographic follow up was necessary, as reoperation of the aortic valve was required in more than 10% of the collective, with an average follow up of five years. Reoperation was mainly related to secondary dilatation of the aortic root.

Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Disease.

BACKGROUND Limited information exists describing the results of transcatheter aortic valve (TAV) replacement in patients with bicuspid aortic valve (BAV) disease (TAV-in-BAV). OBJECTIVES This study sought to evaluate clinical outcomes of a large cohort of patients undergoing TAV-in-BAV. METHODS We retrospectively collected baseline characteristics, procedural data, and clinical follow-up findings from 12 centers in Europe and Canada that had performed TAV-in-BAV. RESULTS A total of 139 patients underwent TAV-in-BAV with the balloon-expandable transcatheter heart valve (THV) (n = 48) or self-expandable THV (n = 91) systems. Patient mean age and Society of Thoracic Surgeons predicted risk of mortality scores were 78.0 ± 8.9 years and 4.9 ± 3.4%, respectively. BAV stenosis occurred in 65.5%, regurgitation in 0.7%, and mixed disease in 33.8% of patients. Incidence of type 0 BAV was 26.7%; type 1 BAV was 68.3%; and type 2 BAV was 5.0%. Multislice computed tomography (MSCT)-based TAV sizing was used in 63.5% of patients (77.1% balloon-expandable THV vs. 56.0% self-expandable THV, p = 0.02). Procedural mortality was 3.6%, with TAV embolization in 2.2% and conversion to surgery in 2.2%. The mean aortic gradient decreased from 48.7 ± 16.5 mm Hg to 11.4 ± 9.9 mm Hg (p < 0.0001). Post-implantation aortic regurgitation (AR) grade ≥2 occurred in 28.4% (19.6% balloon-expandable THV vs. 32.2% self-expandable THV, p = 0.11) but was prevalent in only 17.4% when MSCT-based TAV sizing was performed (16.7% balloon-expandable THV vs. 17.6% self-expandable THV, p = 0.99). MSCT sizing was associated with reduced AR on multivariate analysis (odds ratio [OR]: 0.19, 95% confidence intervals [CI]: 0.08 to 0.45; p < 0.0001). Thirty-day device safety, success, and efficacy were noted in 79.1%, 89.9%, and 84.9% of patients, respectively. One-year mortality was 17.5%. Major vascular complications were associated with increased 1-year mortality (OR: 5.66, 95% CI: 1.21 to 26.43; p = 0.03). CONCLUSIONS TAV-in-BAV is feasible with encouraging short- and intermediate-term clinical outcomes. Importantly, a high incidence of post-implantation AR is observed, which appears to be mitigated by MSCT-based TAV sizing. Given the suboptimal echocardiographic results, further study is required to evaluate long-term efficacy.

Expanding Indications of Transcatheter Heart Valve Interventions.

Transcatheter aortic valve replacement (TAVR) has been established as a less invasive alternative to open-heart surgery in inoperable or high-risk patients presenting with symptomatic severe aortic valve stenosis. The feasibility and efficacy of valve-in-valve implantation in degenerated surgical aortic bioprostheses have also been described and can currently be considered a valuable treatment option in patients deemed unsuitable for repeat cardiac surgery. However, the clinical use of TAVR devices is not limited to the treatment of the tricuspid stenotic aortic valve. Several additional indications including treatment of the bicuspid stenotic aortic valve, aortic regurgitation, and valve-in-valve or valve-in-ring implantation in the mitral or tricuspid position as well as treatment of pure mitral, tricuspid, or pulmonary regurgitation have been described. The purpose of the present review is to summarize the available evidence concerning the emerging off-label use of TAVR devices in current clinical practice. Case examples have been selected to highlight the main procedural steps of each particular intervention.

Mitral Valve Surgery for Rheumatic Lesions in Young Patients

BACKGROUND: The appropriateness of rheumatic mitral valve repair remains controversial due to the risks of recurrent mitral dysfunction and need for reoperation. The aims of this study were to determine the overall short- and long-term outcomes of pediatric rheumatic mitral valve surgery in our center. METHODS: Single-center, observational, retrospective study that analyzed the results of rheumatic mitral valve surgery in young patients, consecutively operated by the same team, between 1999 and 2014. RESULTS: We included 116 patients (mean age = 12.6 ± 3.5 years), of which 66 (57%) were females. A total of 116 primary surgical interventions and 22 reoperations were performed. Primary valve repair was possible in 86 (74%) patients and valve replacement occurred in 30 (26%). Sixty percent of the patients were followed up beyond three months after surgery (median follow-up time = 9.2 months [minimum = 10 days; maximum = 15 years]). Long-term clinical outcomes were favorable, with most patients in New York Heart Association functional class I (89.6%) and in sinus rhythm (85%). Freedom from reoperation for primary valve repair at six months, five years, and ten years was 96.4% ± 0.25%, 72% ± 0.72%, and 44.7% ± 1.34%, respectively. Freedom from reoperation for primary valve replacement at six months, five years, and ten years was 100%, 91.7% ± 0.86%, and 91.7% ± 0.86%, respectively. Mitral stenosis as the primary lesion dictated early reintervention. CONCLUSIONS: Despite the greater rate of reoperation, especially when the primary lesion was mitral stenosis, rheumatic mitral valve repair provides similar clinical outcomes as compared with replacement, with the advantage of avoiding anticoagulation.