Symptomatic aortic stenosis (AS) is an increasing phenomenon as more adults live longer. The gold standard for treating AS is surgical aortic valve replacement (SAVR). Frequently, as older individuals with AS often have multiple comorbidities, a SAVR is determined to be too high risk. Therefore, a less invasive treatment option is available, namely a transcatheter aortic valve implantation (TAVI) or transcatheter aortic valve replacement (TAVR). Such biomedical procedures have encouraged life extension and the decision to intervene commonplace with the aging population. Without an intervention, significant debilitating symptoms affect a person's quality of life (QoL). Multiple quantitative studies evaluating QoL before and after a TAVI have been performed. However QoL has multiple attributes and is not a single construct. By limiting practice to these defined QoL measures, we exclude the human experience and what values individuals describe as important to them. The dilemma in the present medical model is influenced by two paradigms, evidence based medicine and patient centered medicine. Some people opt not to have a TAVI. This study aims to understand what it is like living with aortic stenosis as perceived by the participant and to gain a more meaningful understanding of why some individuals with AS choose not to have this procedure performed. Using a convenience sample of patients who declined a TAVI, a telephone interview with the person focused on their perceived QoL and the implications determining not to pursue a TAVI. In this qualitative phenomenological design, open-ended questions included: 1) What is it like to live with Aortic Stenosis. 2) Why did you choose not to have the TAVI? Interviews will explore emerging themes. Advanced practice nurses are in ideal positions for performing research to gain greater insight on the complexity of people's health choices. As the incidence of AS occurs more frequently in the increasing aged population, TAVI offers a treatment option for those patients who are symptomatic with AS and are not surgical candidates. However, health care providers should focus on the illness, not the disease, and explore the patients' biopsychosocial values with their medical needs. The information gathered in this study will help guide heath care providers with offering holistic health care incorporating both paradigms of evidence based practice and patient centered medicine options on treatment for people with symptomatic AS.

Introduction. Computational modelling has been used widely in biological and clinical applications, but relatively less in surgical design and optimization. Magnetic resonance image (MRI)-based right ventricle (RV) models were introduced for patients with repaired Tetralogy of Fallot (rTOF) to assess ventricle cardiac function, and to identify morphological and mechanical parameters which can be used to predict and optimize post-surgery cardiac outcome. Tetralogy of Fallot is a common congenital heart defect which includes a ventricular septal defect and severe right ventricular outflow obstruction, account for the majority of cases with late onset RV failure. The current surgical approach for the patients with repaired ToF including pulmonary valve replacement/insertion (PVR) has yielded mixed results. It is of great interest to identify parameters which may be used to predict surgical cardiac function outcome after PVR. Data, Model, and Methods. Cardiac Magnetic Resonance (CMR) data from 20 healthy volunteers (11 males, mean year : 22.8) and 56 TOF patients (37 males, mean year : 25.3) were provided by Children's Hospital - Boston, Harvard Medical School from our NIH-funded project (R01 HL089269). RV wall thickness (WT), circumferential and longitudinal curvature (C-cur and L-cur), surface area (SA) and surface to volume ratio (SVR) were obtained based on CMR data for morphological analysis. 6 healthy volunteers and 16 TOF patients were chosen to construct 3D computational models for mechanical analysis. The 3D CMR-based RV/LV/Patch combination models included a) isotropic and anisotropic material properties, b) myocardial fiber orientation, c) active contraction with two zero-load geometries, and d) fluid-structure interactions. The models were used to obtain the assessment for RV mechanical conditions, which might be helpful for PVR surgical outcome prediction. All the computational models were built and solved in a commercial finite element software ADINA. Statistical methods including Linear Mixed- effort Method and Logistical regression were used in the morphological and mechanical analysis to find out potential indicators for predicting PVR outcome from the morphological and mechanical parameters. Results. In morphological analysis, statistically significant differences were found in RV SA and SVR between better-outcome patient group (BPG) and worse-outcome patient group (WPG). At begin of ejection, mean RV SA of BPG was 13.6% lower than that from WPG (241.1 cm2 v.s. 279.0 cm2, p =0.0161). Mean RV SVR of BPG was 13.1% lower than that from WPG (1.26 cm2/ml v.s. 1.45 cm2/ml, p =0.0271). Similar results were also found in RV SA and SVR at begin of filling. Furthermore, RV EF change from pre- to post-PVR were found negatively correlated with RV SA and SVR. In mechanical analysis, 22 structure-only models with one zero-load geometry (1G) were constructed to obtain stress/strain distributions. Stress-P1 from BPG was found to be closer to that from HG, compared to Stress- P1 of WPG. At the beginning of ejection, mean Stress-P1 of BPG was only 6.8% higher than that from healthy group (p =0.6889), while average Stress-P1 of WPG was 84.1% higher than that of healthy group (p =0.0418). Similar results were also found at begin of filling. The results suggested that comparing patients' RV stress values with healthy RV stress values may help identify patients with possible better outcome. The models with two zero-load geometries (2G models) and FSI models were also constructed. Their numerical results indicated that 2G models can provide end-ejection and end-filling results which were not available in 1G models, and FSI models can provide flow velocity, pressure and shear stress information which lacked in structure-only models (1G and 2G models). Conclusion. In vivo image-based 3D patient- specific computational models could lead to considerable potential gain not only in surgical design and outcome prediction, but also in understanding the mechanisms of RV failure for patients with repaired TOF.

Abstract The repair of degenerative mitral valve regurgitation has been shown to be an effective procedure with durable results. The techniques for mitral valve repair are not completely risk-free for late failure, and the identification of factors associated with this increased risk is of clinical relevance as it permits an appropriate selection of patients for whom mitral valve surgery should be offered and by which technique. The European system for cardiac operative risk evaluation score (EuroSCORE) has been used and demonstrated worldwide to be a valid tool for the prediction of immediate postoperative outcome after coronary artery bypass surgery. There are only a few studies which examine its value in heart valve surgery. Mitral valve repair has been shown to be associated with significant improvement in terms of functional capacity, but the late quality of life in these patients has not been adequately assessed, and there is no data on the quality of life of long-term survivors. The study population consisted of two groups of patients operated on at our institution. The first group included 164 patients who underwent isolated or combined mitral valve repair for mitral valve regurgitation during the period 1993 to 2000, while the second group consisted of 207 patients who underwent mitral valve repair (164 patients) or replacement (43 patients) for isolated mitral valve regurgitation during the same time-period. The first study aimed to identify preoperative variables which may have impact on the 30-day postoperative outcome. In the second study, the long-term outcome after mitral valve repair was evaluated in order to identify the risk factors associated with late failures. The third study analyzed quality of life after valve repair and compared it to that of an age- and gender-adjusted Finnish general population. In the fourth study, the validity of EuroSCORE was tested in predicting the immediate and late outcome of patients who had undergone mitral valve repair or replacement for isolated valve regurgitation. Patient age, a history of prior cardiac surgery and NYHA functional class were independent predictors of poor outcome. A residual regurgitation grade of more than one immediately after primary repair and chronic pulmonary disease were independent predictors of mitral valve reoperation. After valve repair, quality of life was similar to the age- and sex-adjusted general Finnish population. Both additive and logistic EuroSCOREs were predictors of the immediate and late outcomes of patients after surgery for mitral valve regurgitation.

Abstract Aortic valve stenosis (AS) is one of the most diffuse valvular diseases in developed countries. AS is a progressive disease, which usually results in serious life-threatening adverse events. Defining a treatment strategy for AS is a focus of cardiovascular research, although the topic is still controversial because of its related clinical and economical implications. Surgical aortic valve replacement (AVR),which is regarded as the gold standard for the treatment of severe symptomatic AS, affords excellent results, particularly in asymptomatic patients with good functional status. AVR requires the institution of cardiopulmonary bypass and aortic cross-clamping, and the duration of these procedures is directly associated with increasing morbidity and mortality, especially in patients with preoperative comorbidities. Accordingly, techniques aimed at decreasing the duration of cardiopulmonary bypass and aortic cross-clamping have the potential to improve postoperative outcomes of AVR. In the present study, we demonstrated that the Perceval sutureless bioprosthesis could significantly reduce the duration of the surgical procedure. This was associated with improved immediate postoperative outcomes and long-term freedom from adverse events. The use of a Perceval sutureless bioprosthesis can facilitate AVR through minimally invasive approaches and is associated with fewer transfusions of packed red cells compared to full sternotomy approaches, even with traditional stented bioprostheses. It could be expected that patients at intermediate-high risk would benefit more from the combination of a fast surgical procedure, performed with reduced surgical invasiveness. When compared to transcatheter aortic valve implantation (TAVI), the Perceval sutureless bioprosthesis was associated with increased incidence of device success as well as less paravalvular leak, with similar immediate and 1-year outcomes. Finally, AVR with the Perceval sutureless bioprosthesis provided excellent hemodynamics at rest and under high workload. The significant increase of effective orifice area under stress suggests that the Perceval sutureless bioprosthesis is the valve of choice for patients with small aortic annuli or when prosthesis-patient mismatch is anticipated. / Tiivistelmä Aorttaläpän ahtauma on yksi yleisimmistä läppävioista kehittyneissä maissa. Aorttaläpän ahtauma on etenevä sairaus, joka yleensä johtaa vakaviin henkeä uhkaaviin haittatapahtumiin. Aorttaläpän ahtauman hoitotavasta keskustellaan kiivaasti sydän- ja verisuonitautien tutkimuksessa siihen liittyvien kliinisten ja taloudellisten vaikutusten vuoksi. Aorttaläppäleikkausta, jossa aorttaläppä korvataan proteesilla, on aina pidetty vaikean oireisen aorttaläpän ahtauman hoidon kultaisena standardina, koska sen tulokset ovat erinomaisia, etenkin oireettomilla potilailla, joilla sydämen toiminta on hyvä. Leikkaus vaatii sydän-keuhkokoneen käyttöä ja aortan sulkemista, joiden kesto on suoraan yhteydessä kasvavaan sairastavuuteen ja kuolleisuuteen erityisesti potilailla, joilla on muitakin sairauksia. Niinpä tekniikat, jotka lyhentävät sydän-keuhkokoneen käyttöaikaa ja aortan sulkuaikaa, voivat mahdollisesti parantaa aorttaläppäleikkauksen tuloksia. Tässä tutkimuksessa osoitettiin, että ompeleettoman biologisen Perceval-läppäproteesin käyttö vähensi merkittävästi leikkauksen kestoa. Tämä oli yhteydessä parantuneisiin lyhyen ja pitkän aikavälin tuloksiin leikkauksen jälkeen. Ompeleettoman biologisen Perceval-läppäproteesin käyttö voi helpottaa aorttaläppäleikkausta, koska se voidaan asentaa vähemmän kajoavasta avauksesta, ja siihen liittyy vähemmän punasolusiirtoja rintalastan kokoavaukseen verrattuna, myös silloin kun käytetään kokoavausta ja perinteisiä stenttibioproteeseja. Voisi olla odotettavaa, että keskisuuren tai suuren riskin potilaat hyötyisivät enemmän leikkauksesta, jossa yhdistyvät toimenpiteen nopeus ja vähäisempi kajoavuus. Katetriteitse asennettuun biologiseen keinoläppään (TAVI) verrattuna ompeleeton biologinen Perceval-läppäproteesi oli yhteydessä parempaan laitteen toimimiseen ja pienempään paravalvulaariseen vuotoon. Muut tulokset heti leikkauksen jälkeen ja yhden vuoden seurannassa olivat samanlaisia. Lopuksi voidaan todeta, että aorttaläppäleikkaukseen ompeleettomalla biologisella Perceval-läppäproteesilla liittyi erinomainen hemodynamiikka levossa ja korkean työkuorman aikana. Stressin aikaisen tehokkaan aorttaläpän aukon pinta-alan merkittävä kasvu osoittaa, että ompeleeton biologinen Perceval-läppäproteesi on hyvä valinta potilaille, joilla on pieni aorttaläpän aukko tai kun on odotettavissa proteesin ja potilaan yhteensopimattomuutta.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13399号 / 論医博第2223号 / 新制||医||1051(附属図書館) / (主査)教授 今中 雄一, 教授 佐藤 俊哉, 教授 福田 和彦 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Transcatheter aortic valve replacement in the setting of failed surgical bioprosthesis (valve-in-valve) is a valuable option for patients with bioprosthetic aortic stenosis or regurgitation who are deemed high risk for repeat open heart surgery. Although the procedure is successful with proper preprocedural assessment, instances of left main (LM) coronary artery ostium obstruction have been documented. We present a case of LM coronary obstruction in the immediate postoperative period following implantation of a 20-mm Edwards Sapien 3 valve inside the degenerated 21-mm Mitroflow bioprosthesis stenosis, which was treated with double stenting alongside the Edwards Sapien 3 valve creating a channel (“neo left main”) that extended from mid-LM to the upper margin of the Edwards Sapien 3 valve. Although valve-in-valve in a Mitroflow degenerated bioprosthesis is a relatively safe procedure, 2 or more stents may be necessary to scaffold a channel to the coronary arteries between Edwards Sapien 3 prosthesis and aorta in the event of a coronary obstruction.

Objective: Studies have shown that iodinated radiocontrast use is associated with acute renal failure especially in the presence of chronic kidney disease and multiple factors modulate this risk. The purpose of this meta-analysis is to compare the incidence of renal failure requiring hemodialysis between transfemoral (TF) and transapical (TA) transcatheter aortic valve replacement using the Edwards valve. Methods: The PubMed database was searched from January 2000 through December 2014. A total of 10 studies (n = 2,459) comparing TF (n = 1,268) and TA (n = 1,191) TAVR procedures using the Edwards valve were included. Variables of interest were baseline logistic EuroSCORE, prevalence of diabetes mellitus, hypertension, peripheral arterial disease, chronic kidney disease and amount of contrast used. The primary endpoint was incidence of renal failure requiring hemodialysis. The odds ratio and 95% CI were computed and P < 0.05 was considered as the level of significance. Results: The logistic EuroSCORE was significantly higher in TA compared to TF (P = 0.001) TAVR. The amount of contrast (mL) used was significantly higher in the TF group compared to the TA group (mean difference: 36.9, CI: 25.7-48.1, P < 0.001). The incidence of hemodialysis following the procedure was significantly higher in the TA group compared to TF group (odds ratio = 4.3, CI: 2.4-7.8, P < 0.00001). Conclusions: This meta-analysis suggests that despite the lower amount of contrast used in TA-TAVR, the incidence of renal failure requiring hemodialysis was higher with the Edwards valve. This suggests that the incidence of renal failure requiring hemodialysis after TAVR is associated with baseline comorbidities in the TA-TAVR group rather than the volume of contrast used.

Objectives: In patients with severe aortic stenosis who are at high risk for surgery, transcatheter aortic valve replacement (TAVR) has emerged as an alternative procedure using EV or CV. The objective of this meta-analysis is to compare 1-year mortality and major adverse cardiovascular and cerebrovascular events (MACCE) between Edwards valve (EV) and Medtronic CoreValve (CV). Methods: PubMed and the Cochrane Center Register of Controlled Trials were searched through December 2014. Twenty seven studies (n = 12,249) comparing TAVR procedure that used EV (n = 5745) and CV (n = 6504) were included. End points were procedural success rates, post-procedural mortality, myocardial infarction (MI), stroke, major bleeding, major vascular complications, incidence of new permanent pacemaker (PPM) placement and new left bundle branch block (LBBB). The odds ratio (OR) with 95% confidence interval (CI) was computed and p < 0.05 was considered for significance. Results: There were no significant differences between EV and CV for post-procedural in-hospital, 30-day and 1-year all-cause mortality rates (p = 0.53, 0.33 and 0.94 respectively), cardiovascular mortality (p = 0.61), stroke (p = 0.54), major bleeding (p = 0.25) and major vascular complications (p = 0.27). MI was significantly lower with EV compared to CV (OR: 0.56, CI: 0.35-0.89, p = 0.01). Placement of new PPM and new onset LBBB were significantly higher in CV compared to EV (OR: 3.35, CI: 2.96-3.79, p < 0.00001 and OR: 6.55, CI: 4.76-9.03, p < 0.00001 respectively). Conclusions: The results of our meta-analysis suggest that TAVR procedure using CV may be associated with a higher incidence of MI, new PPM placement, and new onset LBBB compared to EV. However, the type of valve placed does not affect mortality.

No description available.

Ischemia caused by particles becoming dislodged during transcatheter aortic valve replacement (TAVR) is a possible complication of TAVR. The particles that become dislodged can travel out of the aortic valve, into the aortic arch, and then into either the brachiocephalic artery, the left common carotid artery, the left subclavian artery or continue into the descending aorta. If the particles continue into the descending aorta it poses no risk of causing ischemia however if it travels into the other arteries then it increases the possibility of the particle causing an ischemic event. The goal of this study is to determine what parameters cause the particle to enter one artery over another. The parameters analyzed are the particle diameter, the particle density, the blood pressure, and the diameter of the catheter used in the surgery. This was done by creating a finite element model in COMSOL Multiphysics® to track the particles flowing through a scan of an actual aortic arch. It was determined that the particle diameter, particle density, and the blood pressure affect which artery the particles take to exit the aortic arch. However the diameter of the surgical catheter used in a transaortic approach is not statistically significant when determining which artery the particles will exit. The study shows that larger diameter particle would lead to a higher transmissions probability into the brachiocephalic artery, the left common carotid artery, and the left subclavian artery while a smaller diameter particle would have a higher transmission probability for the descending aorta. Averaging all particle diameters, densities and blood pressure found that 54.95 ± 13.66% of the particles released will travel into the cerebral circulatory system.