Comparison of Staphylococcus Aureus Endocarditis Risk Factors With Bacteremia

Introduction: Infective endocarditis (IE) is endothelial damage of the endocardium, which is caused by infection. The etiologic agents' highest mortality and morbidity rates are associated with staphylococcus aureus (S. aureus). Accordingly, the knowledge of different risk factors for IE caused by the S. aureus is necessary.Material and methods: This study is an observational-analytical retrospective cohort study on 139 patients with staphylococcus aureus bacteremia (SAB), who referred to a cardiac center during 2011-2019. This study aimed to evaluate the risk factors in 48 patients with staphylococcus aureus endocarditis, who were selected from139 patients with S. aureus bacteremia. Results: The mean age (±SD) of the patients is 56.61 (±16.58), and85 (61.2%) persons are male. Forty-eight patients (34.5%) are diagnosed with staphylococcus aureus endocarditis regarding Duke criteria. In this study, the following risk factors were significantly associated with S. aureus endocarditis: age (p=0.003), long-term bacteremia (p=0.041), prosthetic heart valve (p=0.016), pre-existing IE (p=0.048), and embolic events (p=0.039).Conclusion: According to the findings, a significant number of patients with staphylococcus aureus bacteremia (SAB) have IE with different risk factors. Future studies with a larger sample size are recommended to detect IE risk factors.

365 Combining mechanisms of prosthetic valve dysfunction

A 32-year-old female was referred to our outpatient clinic for exertional dyspnoea that had worsened in the preceding months. She had a history of mitral and aortic valve replacement with bileaflet mechanical prosthesis (St. Jude Master n. 25 and Medtronic Open Pivot n. 16, respectively) for rheumatic heart disease. A recent echocardiography showed borderline-high trans-aortic gradients (mean 26 mmHg, peak 42 mmHg). Transthoracic echocardiography revealed abnormal aortic transprosthetic flow (peak velocity 442 cm/s, mean gradient 48 mmHg). Continuous Wave Doppler signal was rounded with a long acceleration time (108 ms). Effective orifice area (EOA) was 0.8 cmq (index EOA 0.48 cmq/mq) and Doppler Velocity Index 0.28. Further investigations revealed no signs of infections but suboptimal anticoagulation (INR 2.5). Transesophageal 3D echocardiography was suggestive for hypomobility of the prosthetic leaflets and the presence of an isoechoic mass encircling the ventricular side of the aortic prosthesis compatible with pannus overgrowth. Cardiac CT confirmed the presence of a symmetrical reduction in the systolic opening of both leaflets. The patient underwent a redo of aortic valve replacement that confirmed the presence of an asymmetric subprosthetic pannus overgrowing on the previously implanted surgical pledgets. After pannus debritment a St. Jude Regent n. 21 was implanted. The patient experienced complete symptomatic resolution. We presented the case of a prosthetic aortic valve dysfunction due to a combination of patient-prosthesis mismatch and pannus overgrowth. In our patient, as assessed in the old echocardiographic examinations, the presence of mildly elevated transprosthetic gradients was suggestive for prosthesis undersizing related to body surface area. In this scenario, subvalvular pannus formation caused significant changes in prosthetic valve transvalvular flow dynamic leading to prosthesis dysfunction. This case emphasises the crucial role of echocardiographic follow up in detection of causes of prosthetic heart valve dysfunction and how optimal valve sizing is paramount in aortic valve replacement.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

Background Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles. Method The review is based on a PubMed literature search using the search terms “transcatheter heart valve”, “TAVI”, “TAVR”, “CT”, “imaging”, “MR” over a period from 2010–2020, combined with personal comments based on the author’s experience. Results and Conclusion CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration. Key Points: Citation Format

Abstract 1122‐000166: Stroke Severity Factors in patients with Acute Ischemic Stroke and Heart Failure Stratifying by Age

Introduction : The goal of this study is to investigate the clinical risk factors associated with acute ischemic stroke (AIS) severity in heart failure (HF) patients above and below 70 years old using the National Institutes of Health Stroke Scale (NIHSS) as a measure for stroke severity. Methods : This study uses retrospective analysis of AIS patients who were previously diagnosed with HF. Data was collected from a regional stroke center from January 2010 to June 2016. Multivariate logistic regression identified the factors associated with stroke severity, with a NIHSS score <7 indicating low severity and a score ≥7 indicating high severity. These results were stratified by patient ages of < and ≥70 years old. Results : A total of 590 patients presented with AIS and a previous diagnosis of HF. The AIS‐HF population contained 223 patients that were <70 years old and 367 that were ≥70 years old. In the AIS‐HF population, patients who were ≥70 years old who presented with coronary artery stenosis (CAS) (OR = 8.592, 95% CI, 2.123‐34.772, P <0.003), prosthetic heart valve (OR = 22.028, 95% CI, 1.454‐333.746, P <0.026), elevated systolic blood pressure (OR = 1.014, 95% CI, 1.002‐1.026, P < 0.024), and tissue plasminogen activator (tPA) administration (OR = 4.002, 95% CI, 1.912‐8.377, P < 0.001) were associated with a higher NIHSS. Alternatively, those that presented with gender differences (OR = 0.466, 95% CI, 0.235‐0.925, P < 0.029), family history of stroke (OR = 0.084, 95% CI, 0.010‐0.726, P < 0.024), obesity (OR = 0.493, 95% CI, 0.261‐0.930, P < 0.029), smoking (OR = 0.253, 95% CI, 0.063‐1.022, P < 0.054), serum creatinine (OR = 0.629, 95% CI, 0.399‐0.992, P < 0.046), INR level (OR = 0.457, 95% CI, 0.191‐1.094, P < 0.079) were associated with a lower NIHSS. Conclusions : The data revealed a variety of components that may affect Stroke Severity in AIS patients with HF. The associated factors exhibited significant differences between distinct age groups. AIS‐HF patients ≥70 years old who presented with CAS, prosthetic heart valve, elevated systolic blood pressure, and received tPA administration were associated with higher stroke severity (≥7 NIHSS) compared to <70 years old group. Identifying more concrete clinical and demographic associations may aid in the identification and evidence‐based management of patients who suffer from AIS.

Normal imaging findings after ascending aorta prosthesis implantation on 18F-Fluorodeoxyglucose Positron Emission Tomography with computed tomography

Background To diagnose abnormal 18F-Fluorodeoxyglucose (18F-FDG) uptake in suspected endocarditis after aortic root and/or ascending aorta prosthesis (ARAP) implantation, it is important to first establish the normal periprosthetic uptake on positron emission tomography with computed tomography (PET/CT). Methods Patients with uncomplicated ARAP implantation were prospectively included and underwent 18F-FDG-PET/CT at either 12 (± 2) weeks (group 1) or 52 (± 8) weeks (group 2) after procedure. Uptake on three different locations of the prosthesis (“cranial anastomosis (CA),” “prosthetic heart valve (PHV),” “ascending aorta prosthesis (AAP)”) was scored visually (none/low/intermediate/high) and quantitatively (maximum standardized uptake value (SUVmax) and target-to-background ratio (SUVratio). Results In total, 20 patients (group 1: n = 10, group 2: n = 10) (mean age 64±7 years, 70% male) were included. Both groups had similar visual uptake intensity for all measured areas (CA: mostly low-intermediate (16/20 (80%)), p = .17; PHV: low-intermediate (16/20 (80%)), p = .88; AAP: low-intermediate (19/20 (95%)), p = .48). SUVmax for CA was 5.6 [4.1-6.1] and 3.8 [3.1-5.9] (median [IQR], p = .19), and around PHV 5.0 [4.1-5.7] and 6.3 [4.6-7.1] (p = .11) for groups 1 and 2, respectively. SUVratio for CA was 2.8 [2.3-3.2] and 2.0 [1.7-2.6] (median [IQR], p = .07) and around PHV 2.5 [2.4-2.8] and 2.9 [2.3-3.5] (median [IQR], p = .26) for groups 1 and 2, respectively. Conclusion No significant differences were observed between PET/CT findings at 3 months and 1 year after ARAP implantation, warranting caution in interpretation of PET/CT in the first year after implantation.

Awareness of medical emergencies among dental practitioners in three Egyptian Dental Schools: A cross-sectional study

Objectives: To evaluate the awareness of medical emergencies among dental practitioners in three dental schools. Material and methods: The study group included 384 dental practitioners, including dental staff members, post-graduate students, and dental interns. These professionals were attending three dental educational institutions in Egypt. Two of them were governmental and one was a private school. The educational model is almost the same in most Egyptian dental schools. Results: The response rate was 100%. Most of the participants worked in private academia (44.16%) or practice (42.34%) and 65.20% of them were females. The participants recorded medical history and filled a form (91.17%, 80.52 % respectively) while only 41.82% obtained the vital signs. Among the participants, 48.57 % were confident about handling medical emergency and 74.29 % reported their capability of intramuscular injection while only 25.71 % for intravenous injection and 49.35% knew about emergency kits. Management knowledge of airway obstruction and prosthetic heart valve patients was reported by 80.27 % and 71.94 % respectively, while less percentage for activation of EMS, chest compression, CPR ratio, and infant rescue breathing. The mean preparedness percent score was 54.57% and it was inversely correlated to the years of experiences and directly correlated to the degree of confidence in their ability to manage the dental emergency. Conclusion: The current study results reflected a deficiency in the dental practitioner awareness about the medical emergency especially the practical part. Keywords Dentists; Cross-sectional studies; Emergencies; Educational models; Dental schools.

1258 Computational Modelling Of 3D Printed Scaffolds for Heart Valve Regeneration

Aim Prosthetic heart valve replacement remains the gold standard treatment for valvular heart disease. However, its durability is limited and there is thus a need to develop an understanding of the feasibility of alternative replacement therapies. 3-dimensional printing of heart valves has been explored due to its patient-specific design and control of desired biomechanical properties. Computational studies of the synthetic valves will contribute to optimisation of designs, as well as improved understanding of the biomechanical behaviour of the complex structures. Method Aortic valve dimensions at an average of 100mmHg were used for the computerised design of the valves. Fine Element Analysis modelling generated computational experiments alongside predicted results. Simulated radial pressures tests were conducted at pressures from 0mmHg to 140mmHg and compression tests were conducted at displacement levels between 0-10mm. A Young’s modulus of 0.5 MPa was used. All simulations were conducted in a quasi-static manner. Results As the radial pressure on the valves increased, the Mises stresses increased. The maxium Mises stress of the heart valve was 0.09MPa and 0.13MPa under the pressures of 90mmHg and 140mmHg respectively. As valve displacement increased, the Mises stress of the heart valves proportionally rose. In simulated radial pressures tests, the compressive force was 0.19N at 1mm compressive displacment and 1.8N at 10mm compressive displacment. Conclusions The simulations demonstrated that 3D-printed heart valve scaffolds can withstand simulated radial pressure and compression tests. A further mechanical tests of the printed scaffold and understanding of its response to hemodynamic dynamic flow is required for the continuity of further study.