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Obwohl immer mehr Patienten der TAVI zugänglich gemacht werden können, ist die Datenlage bezüglich des Langzeitüberlebens aktuell nicht ausreichend. Besonders rar sind Daten zur Langzeitauswertung bei den Patientengruppen mit mäßiggradig reduzierter Ejektionsfraktion (LVEF 40-49%) oder hochgradig reduzierter Ejektionsfraktion (LVEF < 40%). Daher hat sich diese Arbeit zum Ziel gesetzt, diese speziellen Patientengruppen auf das Langzeitüberleben hin zu untersuchen. Es wurden dazu die Daten von 142 Patienten ausgewertet, die von 2009 bis 2016 im Herzzentrum Dresden eine TAVI erhalten haben. Der Gruppe mit einer mäßiggradig reduzierten EF konnten 58 Patienten zugeordnet werden und der Gruppe mit hochgradig reduzierter EF 84 Patienten. Nach Erhebung der Basiswerte wurden beide Patientengruppen miteinander verglichen um Unterschiede zwischen präoperativen - und postoperativen Parametern sowie der Mortalität zu detektieren. Anschließend wurden die Patienten mit der stärker reduzierten EF gesondert in Bezug auf Hospitalmortalität und Gesamtmortalität hin untersucht. Weiterhin wurden die entsprechenden Prädiktoren isoliert und auf Relevanz untersucht. Das Langzeitüberleben wurde für jede Probandengruppe getrennt ermittelt und mittels Kaplan-Meier-Kurve graphisch dargestellt. In dieser Arbeit konnte bewiesen werden, dass die EF sich als Prädiktor für die Gesamtmortalität eignet, da diese statistisch signifikant höher ist, wenn der Basiswert der EF < 40 % beträgt (48,8 % für EF < 40 % vs. 24,1 % für EF ≥ 40 %; p = 0,003). Ebenfalls wies sie für den Prädiktor EF < 40 % eine statistisch signifikante Unabhängigkeit nach (p = 0,04989). Zudem konnte gezeigt werden, dass die Gesamtmortalität in der Gruppe der Patienten mit stärker reduzierter EF um 19 % statistisch signifikant höher ist als in der Gruppe der Patienten mit mäßiggradig reduzierter EF (28,9 vs. 9,9 %; p = 0,003). Auch Prädiktoren für die Hospitalmortalität bei stärker reduzierter EF konnten mit den Parametern postoperative PVL (p = 0,044), postoperative Vmax (p = 0,034), postoperativer dpmax (p = 0,023) und postoperativer dpmean (p = 0,044) ermittelt werden. Die Gesamtmortalität betrachtend konnte für diese Patientengruppe kein statistisch signifikanter Prädiktor gefunden werden. Der Unterschied zwischen den Überlebenswahrscheinlichkeiten beider Gruppen lag nach einem Jahr bei 6,9 % (77,8 ± 6,2 vs. 70,9 ± 5,4 %), nach zwei Jahren bei 17,6 % (75,5 ± 6,4 vs. 57,9 ± 5,9 %) und zum längsten vergleichbaren Zeitraum nach 4,5 Jahren bei 23,5 % (60,0 ± 10,4 % vs. 36,5 ± 7,0 %), jeweils zum Nachteil der Probanden mit EF < 40 %.:1 EINLEITUNG 1.1 MOTIVATION DER ARBEIT 1.2 KRANKHEITSBILDER DES HERZENS DIE TAVI INDIZIEREN 1.2.1 AORTENKLAPPENSTENOSE 1.3 KATHETERGESTÜTZTER AORTENKLAPPENERSATZ 1.3.1 ENTWICKLUNG DER INDIKATIONSSTELLUNG ZUR TAVI MIT HILFE FÜHRENDER STUDIEN 1.3.2 INDIKATIONSSTELLUNG ZUR TAVI 1.4 MORTALITÄT – EINSCHÄTZUNG UND VERRINGERUNG 1.4.1 VORUNTERSUCHUNGEN 1.4.2 KOMPLIKATIONEN NACH TAVI 1.5 ZIEL DER STUDIE 2 MATERIAL UND METHODEN 2.1 EINGESCHLOSSENE PATIENTEN 2.2 RETROSPEKTIVE DATENERHEBUNG MITTELS MCC UND SEPAVAS 2.2.1 ERHOBENE PARAMETER 2.3 POSTALISCHE PATIENTENANSPRACHE 2.4 DATENAUFBEREITUNG UND VERFEINERUNG 2.5 ETHIKVOTUM 3 ERGEBNISAUSWERTUNG 3.1 STATISTIK 3.1.1 DESKRIPTIVE STATISTIK 3.1.2 SCHLIEßENDE STATISTIK 3.2 ALLGEMEINE ANALYSE 3.2.1 PATIENTEN BASISPARAMETER 3.2.2 OP-DATEN 3.2.3 POSTOPERATIVE HÄMODYNAMIK 3.2.4 POSTOPERATIVE KOMPLIKATIONEN NACH TAVI 3.2.5 POSTOPERATIVES OUTCOME 3.3 MORTALITÄTSANALYSE 3.3.1 UNIVARIATE MORTALITÄTSANALYSE BEZOGEN AUF GESAMTMORTALITÄT 3.3.2 UNIVARIATE MORTALITÄTSANALYSE BEZOGEN AUF HOSPITALMORTALITÄT 3.4 SUBGRUPPENANALYSE 3.4.1 VERGLEICH DER GRUPPEN EF ≥ 40 % UND < 40 % 3.4.2 SUBGRUPPENANALYSE DER EF < 40 % FÜR DIE HOSPITALMORTALITÄT 3.4.3 SUBGRUPPENANALYSE DER EF < 40 % FÜR DIE GESAMTMORTALITÄT 3.5 WEITERE STATISTISCHE ANALYSE 3.5.1 MULTIVARIANZANALYSE 3.5.2 COX REGRESSION 2 3.5.3 ÜBERLEBENSANALYSE NACH KAPLAN-MEIER 4 DISKUSSION 4.1 BEDEUTUNG DER ERGEBNISSE UND VERGLEICH MIT ANDEREN STUDIEN 4.1.1 GEEIGNETE PRÄDIKTOREN FÜR DIE MORTALITÄT 4.1.2 DIE EJEKTIONSFRAKTION ALS PRÄDIKTOR FÜR DIE MORTALITÄT 4.1.3 LANGZEITÜBERLEBENSWAHRSCHEINLICHKEIT 4.2 LIMITIERUNGEN DER ARBEIT 5 FAZIT 6 ZUSAMMENFASSUNG 7 SUMMARY 8 LITERATURVERZEICHNIS 9 TABELLENVERZEICHNIS 10 ABBILDUNGSVERZEICHNIS 11 DANKSAGUNG 12 ANLAGE 1 13 ANLAGE 2

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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.

Objectives: As surgical experience with infective endocarditis following transcatheter aortic valve replacement is scarce, this study compared the perioperative and short-term outcomes of patients suffering from endocarditis following surgical aortic valve replacement and transcatheter aortic valve replacement. Methods: Between January 2013 and December 2020, 468 consecutive patients were admitted to our center for surgery for IE. Among them, 98 were operated on for endocarditis following surgical aortic valve replacement and 22 for endocarditis following transcatheter aortic valve replacement. Results: The median EuroSCORE II (52.1 (40.6–62.0) v/s 45.4 (32.6–58.1), p = 0.207) and STS-PROM (1.8 (1.6–2.1) v/s 1.9 (1.4–2.2), p = 0.622) were comparable. Endocarditis following transcatheter aortic valve replacement accounted for 13.7% of the aortic prosthetic valve endocarditis between 2013 and 2015; this increased to 26.9% in the years 2019 and 2020.Concomitant procedures were performed in 35 patients (29.2%). The operative mortality was 26.5% in the endocarditis following surgical aortic valve replacement group and 9.1% in the endocarditis following transcatheter aortic valve replacement group (p = 0.098). Upon follow-up, survival at 6 months was found to be 98% in the group with endocarditis following surgical aortic valve replacement and 89% in the group with endocarditis following transcatheter aortic valve replacement (p = 0.081). Conclusions: Patients suffering from endocarditis following surgical aortic valve replacement and transcatheter aortic valve replacement present with comparable risk profiles and can be surgically treated with comparable results. Surgery as a curative option should not be rejected even in this intermediate-risk cohort

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No description available.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23767号 / 医博第4813号 / 新制||医||1056(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 大鶴 繁, 教授 小西 靖彦, 教授 森田 智視 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Continuous-wave (CW) Doppler recordings of ascending aortic maximal blood flow acceleration (PkA), maximal velocity (PkV) and systolic velocity integral (SVI) were taken at each stage of a graded exercise treadmill test on two separate days with 30 physically active adult males. Signals were measured (Quinton Exerdop) for all cardiac cycles in the 3rd minute of each stage using a hand-held probe positioned at the suprasternal notch. A dedicated microcomputer, programmed to select "valid" beats on the basis of value consistency in the sample set, determined the acceptability of signals. No significant differences were found between the three trial means within each stage on either day for PkA, PkV or SVI. Significant (p <.01) intraclass reliability estimates ranged from r = 0.89 to 0.97 (Pk.A), r = 0.90 to 0.98 (PkV) and r = 0.85 to 0.95 (SVI) . Coefficients of variation were calculated at each stage to estimate the relative consistency of each measure. A gradual reduction of the coefficient of variation was observed for each blood flow measure between stages one and four. The test-retest (between days) reliability coefficients for PkA, PkV and SVI for stages one to four ranged between r = 0.51 to 0.78 (P <.004), but correlations for the pre-exercise baseline and stages five and six were lower. These results indicate that (1) PkA, PkV and SVI demonstrate greater measurement stability within each stage of a graded exercise test than is the case between separate days of measurement at the same stage; and (2) there is modest day-to-day response stability for clinical testing with the Doppler parameter of PkV. Reliability/stability was best in exercise stages which encompass the speed and grade range of 45.0 m•min⁻¹/10%. - 111.7 m•min⁻¹/14%, i.e., those in which all subjects can walk. / Master of Science

Aortic stenosis (AS) is a critical valvular disease often treated by Transcatheter Aortic Valve Replacement (TAVR). This thesis introduces several novel approaches for improving the assessment and management of AS and the associated TAVR procedure. The research presents new indices for characterizing AS progression, including the False Positive Rate (FPR) method for detecting and quantifying calcification in contrast-enhanced computed tomography (CT) images. This method adapts dynamically to the variability in calcium density and offers precise estimates of calcific burden. Additionally, a Minimal Variation Geometry Invariant Parametric Reconstruction (MVGIPR) method was developed to reconstruct the full geometry of the aortic valve complex (AVC). This approach enhances the accuracy of geometric models from routine CT scans, providing detailed 3D models of the aortic valve, including patient-specific anatomical and pathological features. Moreover, the Virtual Transcatheter Aortic Valve Replacement (VTAVR) framework is introduced for TAVR optimization and intervention planning using developments from both previous techniques. This novel simulation-based system incorporates kinematic modeling within a patient-specific parametric geometry to predict device deployment outcomes, including complications such as paravalvular leakage, patient-prosthesis mismatch, and left bundle branch block. By simulating patient-specific device deployment, the VTAVR framework may potentially enhance pre-procedural planning, leading to better surgical outcomes and reduced risks in TAVR procedures. / Thesis / Doctor of Philosophy (PhD) / Aortic stenosis (AS) is a condition where the heart’s aortic valve becomes narrowed due to calcification, restricting blood flow and leading to severe health risks, especially in older adults. This research introduces new ways to measure the progression of this disease and predict complications from the commonly used treatment called Transcatheter Aortic Valve Replacement (TAVR). Using advanced computational models, the study develops personalized aortic valve shape and structure assessment frameworks using routine clinical computed tomography (CT) imaging. Moreover, we introduce a virtual interventional simulation framework that can predict how a patient’s valve may respond to TAVR. This "Virtual TAVR" system may help treating physicians to plan surgeries more accurately by simulating different approaches, allowing them to identify the best treatment strategy for each patient. By improving our ability to predict complications, the system ultimately aims to increase the success rate of these life-saving procedures.