Contemporary review of severe aortic stenosis

Incidence and Predictors of Readmissions to Non-Index Hospitals After Transcatheter Aortic Valve Implantation in the Contemporary Era in New South Wales, Australia

BACKGROUND

In Australia, transcatheter aortic valve implantation (TAVI) is only performed in a limited number of specialised metropolitan centres, many of which are private hospitals, making it likely that TAVI patients who require readmission will present to another (non-index) hospital. It is important to understand the impact of non-index readmission on patient outcomes and healthcare resource utilisation.

METHOD

We analysed linked hospital and death records for residents of New South Wales, Australia, aged ≥18 years, who had an emergency readmission within 90 days following a TAVI procedure in 2013-2022. Mixed-effect, multi-level logistic regression models were used to evaluate predictors of non-index readmission, and associations between non-index readmission and readmission length of stay, 90-day mortality, and 1-year mortality.

RESULTS

Of 4,198 patients (mean age, 82.7 years; 40.6% female) discharged alive following TAVI, 933 (22.2%) were readmitted within 90 days of discharge. Over three-quarters (76.0%) of those readmitted returned to a non-index hospital, with no significant difference in readmission principal diagnosis between index hospital and non-index hospital readmissions. Among readmitted patients, independent predictors of non-index readmission included: residence in regional or remote areas, lower socio-economic status, having a pre-procedure transfer, and a private index hospital. Readmission length of stay (median, 4 days), 90-day mortality (adjusted odds ratio [OR] 1.04, 95% confidence interval [CI] 0.56-1.96) and 1-year mortality (adjusted OR 1.01, 95% CI 0.64-1.58) were similar between index and non-index readmissions.

CONCLUSIONS

Non-index readmission following TAVI was highly prevalent but not associated with increased mortality or healthcare utilisation. Our results are reassuring for TAVI patients in regional and remote areas with limited access to return to index TAVI hospitals.

Prognostic impact of main pulmonary artery to ascending aorta diameter ratio in patients with severe aortic stenosis underwent transcatheter aortic valve implantation

BACKGROUND

Pulmonary hypertension (PH) and right ventricular dysfunction are poor prognostic predictors in patients underwent transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS).

AIMS

The prognostic impact of the main pulmonary artery/ascending aorta diameter ratio (MPA/AOr), measured simply by computed-tomographic angiography (CTA), was investigated in this patient group.

METHODS

A total of 374 retrospectively evaluated patients (mean age 78.1 ± 8.4 years, 192 [51.3%] females) who underwent TAVI for severe AS were included. MPA/AOr was measured on preprocedural CTA in all patients and the effect of this measurement on the presence of PH, in-hospital and 2-year-overall long-term mortality was investigated.

RESULTS

The presence of PH was defined as a systolic pulmonary artery pressure (sPAP) >42 mmHg measured by echocardiography. According to multivariate-logistic-regression analysis, MPA/AOr (adjusted [Adj] odds ratio [OR]: 1.188, confidence interval [CI] 95% [1.002-1.410], p = 0.048), tricuspid annular plane systolic excursion (TAPSE) (adj OR:0.736, CI 95% [0.663-0.816], p < 0.001) and left atrial diameter (adj OR:1.051, CI 95% [1.007-1.098], p = 0.024) were identified as independent predictors of PH. In addition, a statistically significant correlation was found between MPA/AOr and TAPSE (r: -0.283, p < 0.001). Furthermore, MPA/AOr was found to be an independent predictor of both in-hospital (adj OR:1.434, CI 95% [1.093-1.881], p = 0.009) and 2-year long-term (adj OR:1.518, CI 95% [1.243-1.853], p < 0.001) mortality in multivariate analysis including TAPSE, STS score and sPAP. In the 2-year Kaplan-Meier survival probability analysis, an MPA/AOr >0.86 was found to have a hazard ratio of 3.697 (95% CI: 2.341-5.840), with a log-rank p < 0.001.

CONCLUSION

MPA/AOr, which can be measured simply by CTA, may be useful as an indicator of the presence of PH and poor prognosis in patients planned for TAVI for severe AS.

Trends in Economic Burden and Mortality of Hospitalized Patients With Aortic Stenosis in Thailand

This study aimed to assess the temporal trends in aortic stenosis (AS)-related hospitalizations, in-hospital mortality, and economic burden in Thailand. The study cohort was derived from the electronic claim system of the National Health Security Office, which serves as a reimbursement database for all Thai beneficiaries under the Universal Health Coverage Scheme, covering ∼70% of the entire population. Hospitalization, mortality, and costs were estimated by year, with the primary diagnosis for AS-related hospitalizations identified using code I350. The Cochrane Armitage test was used to examine trends in AS-related hospitalization and in-hospital mortality, whereas a nonparametric trend test was used to analyze the trend of hospitalization costs. Of the 8-year period, 10,406 adults were admitted with a primary diagnosis of AS. AS-related hospitalizations increased from 1,274 in 2015 to 1,945 in 2022 (p = 0.251), with the most significant observed in the age group 60 to 79 years (p <0.001). In-hospital mortality increased from 4.8% to 6.1%. Hospitalization cost significantly increased from $2,879 to $3,443 (p <0.001), with an average length of stay of 6.6 ± 9.2 days. The trend of patients admitted with primary diagnosis of AS in Thailand has significantly increased in the age group 60 to 79 years. In-hospital admission is found at older age and is likely to have high mortality rate. The increased hospitalization cost may impose a substantial economic burden on the Thai health care system.

The transcatheter aortic valve implantation: an assessment of the generalizability of the economic evidences following a systematic review

OBJECTIVES

Scientific literature debates on the economic affordability of transcatheter aortic valve implantation (TAVI) in order to give a useful support to decision makers aiming at establishing a reimbursement scheme for TAVI. For this reason, it is important to assess the quality and the generalizability of the existing economic evidences.

METHODS

The first step was to run a literature search according to a predefined population, intervention, comparator, and outcome on the cost and effectiveness of the TAVI procedure in comparison to medical therapy and traditional surgery. Second, a manual search was carried out on the Web sites of the main HTA agencies. Third, the checklist developed by Augustovski et al. was applied in order to assess the quality and the generalizability of the articles resulting from the selection process.

RESULTS

Overall, 106 articles were obtained. Of these, sixty-five articles were excluded since the title was not consistent with the objective. Further selection took place after abstract and full-text reading. In the end, thirty-one documents were included for the review. According to the checklist, none of the articles was considered generalizable and only one was considered transferable which compares the TAVI procedure with Medical Management in inoperable patients.

CONCLUSIONS

Despite the overall quality of the selected studies was considered good, there is still a lack of evidence on whether evidences generated in different contexts can be considered generalizable. Further research on resource consumption and preferences is needed in order to provide decision makers with more robust evidences.

Trends in Transcatheter Aortic Valve Implantation in Australia

Aortic valve stenosis is the most common valvular lesion in Australia, with a rising prevalence in line with the ageing population. Recent trials have demonstrated the efficacy of transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement in consecutively lower surgical risk patient cohorts. Despite this, the current indication for TAVI in Australia is for the treatment of severe symptomatic aortic stenosis in patients who are of prohibitive or high surgical risk and ultimately deemed suitable by a heart team. This article summarises the trends in TAVI in Australia over the last 5 years in terms of funding, accreditation and service delivery, as well as advances in technique, technology, patient selection and local outcomes.

Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients

Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014−2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640−0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778−0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728−0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721−0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607−0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617−0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15−7.01), ischemic heart disease (OR 3.65; CI 1.01−13.2), diabetes (OR 3.88; CI 1.38−10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91−50.2), mitral valve repair (OR 4.47; CI 1.76−11.3), tricuspid valve repair (OR 3.06; CI 1.09−8.58), 3 and more procedures (OR 4.44; CI 1.67−11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions.

In silico modelling of aortic valve implants - predicting in vitro performance using finite element analysis

The competing structural and hemodynamic considerations in valve design generally require a large amount of in vitro hydrodynamic and durability testing during development, often resulting in inefficient "trial-and-error" prototyping. While in silico modelling through finite element analysis (FEA) has been widely used to inform valve design by optimising structural performance, few studies have exploited the potential insight FEA could provide into critical hemodynamic performance characteristics of the valve. The objective of this study is to demonstrate the potential of FEA to predict the hydrodynamic performance of tri-leaflet aortic valve implants obtained during development through in vitro testing. Several variations of tri-leaflet aortic valves were designed and manufactured using a synthetic polymer and hydrodynamic testing carried out using a pulsatile flow rig according to ISO 5840, with bulk hydrodynamic parameters measured. In silico models were developed in tandem and suitable surrogate measures were investigated as predictors of the hydrodynamic parameters. Through regression analysis, the in silico parameters of leaflet coaptation area, geometric orifice area and opening pressure were found to be suitable indicators of experimental in vitro hydrodynamic parameters: regurgitant fraction, effective orifice area and transvalvular pressure drop performance, respectively.

Frailty Assessment in a Cohort of Elderly Patients with Severe Symptomatic Aortic Stenosis: Insights from the FRailty Evaluation in Severe Aortic Stenosis (FRESAS) Registry

Background: Precise evaluation of the degree of frailty is a fundamental part of the global geriatric assessment that helps to avoid therapies that could be futile. Our main objective was to determine the prevalence of frailty in a specific consult of patients undergoing aortic valve replacement. Methods: From May 2018 to February 2020, all consecutive patients ≥75 years old, with severe symptomatic aortic stenosis, undergoing valve replacement in the Principality of Asturias (Northern Spain) were evaluated. Results: A total of 286 patients were assessed. The mean age was 84 ± 4.01 years old; 175 (61.2%) were female. The short performance physical battery score was 8.5 ± 2.4 and the prevalence of frailty was 19.6% (56 patients). In the multivariable analysis, age, Barthel index and atrial fibrillation were independent predictors of frailty. Conclusions: The prevalence of frailty in our sample patients undergoing aortic valve replacement, evaluated by a standardized protocol, was 19.6%.

Reproducible In Vitro Tissue Culture Model to Study Basic Mechanisms of Calcific Aortic Valve Disease: Comparative Analysis to Valvular Interstitials Cells

The hallmarks of calcific aortic valve disease (CAVD), an active and regulated process involving the creation of calcium nodules, lipoprotein accumulation, and chronic inflammation, are the significant changes that occur in the composition, organization, and mechanical properties of the extracellular matrix (ECM) of the aortic valve (AV). Most research regarding CAVD is based on experiments using two-dimensional (2D) cell culture or artificially created three-dimensional (3D) environments of valvular interstitial cells (VICs). Because the valvular ECM has a powerful influence in regulating pathological events, we developed an in vitro AV tissue culture model, which is more closely able to mimic natural conditions to study cellular responses underlying CAVD. AV leaflets, isolated from the hearts of 6-8-month-old sheep, were fixed with needles on silicon rubber rings to achieve passive tension and treated in vitro under pro-degenerative and pro-calcifying conditions. The degeneration of AV leaflets progressed over time, commencing with the first visible calcified domains after 14 d and winding up with the distinct formation of calcium nodules, heightened stiffness, and clear disruption of the ECM after 56 d. Both the expression of pro-degenerative genes and the myofibroblastic differentiation of VICs were altered in AV leaflets compared to that in VIC cultures. In this study, we have established an easily applicable, reproducible, and cost-effective in vitro AV tissue culture model to study pathological mechanisms underlying CAVD. The valvular ECM and realistic VIC-VEC interactions mimic natural conditions more closely than VIC cultures or 3D environments. The application of various culture conditions enables the examination of different pathological mechanisms underlying CAVD and could lead to a better understanding of the molecular mechanisms that lead to VIC degeneration and AS. Our model provides a valuable tool to study the complex pathobiology of CAVD and can be used to identify potential therapeutic targets for slowing disease progression.

Transcatheter aortic valve replacement: An alternative for severe aortic stenosis

ABSTRACT

Transcatheter aortic valve replacement (TAVR) is considered a lower-risk procedure for patients with severe aortic valve stenosis. Several FDA-approved trials performed in the United States support TAVR to be beneficial over surgical aortic valve replacement in certain patient populations. An optimal TAVR program consists of a multidisciplinary team that selects candidates for the procedure based on shared decision-making and the patient's anatomy and risk factors, and follows the patients through the Transcatheter Valve Therapy National Registry.

Improved Exercise Tolerance, Oxygen Delivery, and Oxygen Utilization After Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

Background

Transcatheter aortic valve implantation (TAVI) represents an effective therapeutic procedure, particularly in patients with severe aortic stenosis. We hypothesized that the decreased afterload induced by TAVI would improve exercise capacity by enhancing oxygen uptake in working muscles.

Methods

A standardized exercise test was performed in patients with severe aortic stenosis the day before TAVI and within 5 days thereafter. The main study endpoint was the workload achieved during a 5-minute standardized exercise test. Using electrical cardiometry and near-infrared spectroscopy, we explored and compared the changes in cardiac index (CI), as well as muscular and cerebral tissue oximetry, during the 2 exercise tests.

Results

Thirty patients completed the study protocol. Compared with the pre-TAVI period, patients achieved a higher median workload after TAVI (316 Joules [interquartile range {IQR}: 169–494] vs 190 Joules [IQR: 131–301], P = 0.002). Baseline CI increased from 2.5 l/min per m² (IQR: 2.1–2.9) to 2.9 l/min per m² (IQR: 2.5–3.2; P = 0.009), whereas CI at the end of the exercise test increased from 4.5 l/min per m² (IQR: 3.4–5.3) to 4.7 l/min per m² (3.4–6.4; P = 0.019). At the end of the exercise test, cerebral tissue oximetry increased from 70% (IQR: 65–72) to 74% (IQR: 66–78), and muscle tissue oximetry increased from 62% (IQR: 58–65) to 71% (65–74; P = 0.046 and P < 0.001, respectively).

Conclusions

Early improvement of exercise capacity after TAVI is associated with increased CI and better oxygen utilization in the brain and skeletal muscles.

[Cross-speciality geriatrics: A health-care challenge for the 21st century]

Increasing numbers of older persons are being treated by specialties other than Geriatric Medicine. Specialists turn to Geriatric Teams when they need to accurately stratify their patients' risk and prognosis, predict the potential impact of their, often, invasive interventions, optimise their clinical status, and contribute to discharge planning. Oncology and Haematology, Cardiology, General Surgery, and other surgical departments are examples where such collaborative working is already established, to a varying extent. The use of the term "Cross-speciality Geriatrics" is suggested when geriatric care is provided in clinical areas traditionally outside the reach of Geriatric Teams. The core principles of Geriatric Medicine (comprehensive geriatric assessment, patient-centred multidisciplinary targeted interventions, and input at point-of-care) are adapted to the specifics of each specialty and applied to frail older patients in order to deliver a holistic assessment/treatment, better patient/carer experience, and improved clinical outcomes. Using Comprehensive Geriatric Assessment methodology and Frailty scoring in such patients provides invaluable prognostic information, helps in decision making, and enables personalised treatment strategies. There is evidence that such an approach improves the efficiency of health care systems and patient outcomes. This article includes a review of these concepts, describes existing models of care, presents the most commonly used clinical tools, and offers examples of excellence in this new era of geriatric care. In an ever ageing population it is likely that teams will be asked to provide Cross-specialty Geriatrics across different Health Care systems. The fundamentals for its implementation are in place, but further evidence is required to guide future development and consolidation, making it one of the most important challenges for Geriatrics in the coming years.